Traumatismele Tendonului Ahilian Si Ale Articulatiei Gleznei

MUSCULAR SYSTEM - ANATOMY, FUNCTIONS AND INJURIES

ACHILLES TENDON AND ANKLE INJURIES BIOMECHANICS, MANAGEMENT AND CLINICAL IMPLICATIONS

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MUSCULAR SYSTEM - ANATOMY, FUNCTIONS AND INJURIES

ACHILLES TENDON AND ANKLE INJURIES BIOMECHANICS, MANAGEMENT AND CLINICAL IMPLICATIONS ARTHUR ADAMS EDITOR

New York

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Published by Nova Science Publishers, Inc. † New York

CONTENTS Preface Chapter 1

Chapter 2

vii Effectiveness of Different Physical Therapies in Conservative Treatment of Achilles Tendinopathy: Systematic Review Ana María Díaz López, Daniel Gómez López and Patricia Guzman Carrasco Evaluation of Achilles Tendon Length Changes in Humans Atsuki Fukutani, Akinori Nagano and Tadao Isaka

Chapter 3

The Evolution of the Achilles Tendon B. Tucker and W. S. Khan

Chapter 4

The Biomechanics of Ankle Joint and Its Relevance to Total Ankle Replacement M. R. Nannaparaju and W. S. Khan

1

39

65

77

Bibliography

89

Index

95

PREFACE In this book, the effectiveness of various physical therapies in the conservative treatment of Achilles tendinopathy are reviewed. An evaluation on the length changes in the Achilles tendon in humans is explored as well. The tendon is considered to have a significant role in human movement because it can store and release elastic energy, which enhances the forcegenerating capability of the muscle-tendon complex. The third chapter outlines the advantages and disadvantages of the Achilles tendon and highlights some theories as to why humans may have evolved to have it. The last chapter discusses the basic biomechanical characteristics and forces acting on the ankle under static conditions and their influences on artificial total ankle replacement designs. Chapter 1 - The prevalence of Achilles tendinopathy is unknown (although when considering the partial or complete ruptures is per 100,000 people the consequences of overuse). Its etiology is multi factorial, including increased weight bearing with the knee extension, sudden and violent dorsiflexion and direct trauma, as well as friction with the back of the shoes with high heels. If there is a bony prominence such as Heglund disease, rubbing intensifies and causes a chronic inflammatory painful process. Achilles tendinitis occurs most frequently in male than females by a ratio of 3:1 between the fourth and fifth decades of life. The clinic can be acute or chronic, the chronic understood by one with an evolution of more than 3 months. According to the predisposing factors that act, the lesion is located at different levels of the tendon, there are insertional tendinitis and other non insertional. The treatment of choice for Achilles tendinopathy is conservative, being used ortostatic measures, shock waves, laser, ultrasounds, therapy with

viii

Arthur Adams

eccentric exercises, and other less common techniques such as pulsed light, massage of Cyriax, iontophoresis, acupuncture, among others. It is often combined with anti-inflammatory drugs and injections. Surgical treatment is usually not performed and involves extensive rehabilitation, 3 to 6 months prior to loading on foot. The aim objective of this study was to determine the effectiveness of various physical therapies in the conservative treatment of Achilles tendinopathy. Methods: A systematic review of scientific studies addressing the treatment of Achilles tendinitis was performed by physical agents. A search was conducted on the bases Web of Science, The Cochrane Library, Medline, Lilacs, IBECS, IME, PEDro and ENFISPO, This search was made in both Spanish and English without restriction at the time of the items, performing the last search in February 2015. Randomized controlled trials were included adult patients diagnosed with Achilles tendinopathy, intervention studies, prospective studies and systematic reviews. Assessment of study eligibility was developed by three reviewers independently and unblinded standardized. To classify the critical reading PEDro scale was used along with a critical review of each abstract first, and if this was not conclusive assessment of the full text. Results: After identifying 398 articles 23 articles were analyzed, 3 prospective study (n = 115), 2 case-control studies (n = 258) and 18 controlled clinical trials (n = 889) also were consulted 9 systematic reviews, as well as a Clinical Practice Guideline. Conclusion: This review presented a variety of physical treatment alternatives can be seen in the Achilles tendinitis. The only one that seems effective in isolation and that its effectiveness continues long term are eccentric exercises. Chapter 2 - The tendon is considered to have a significant role in human movement because it can store and release elastic energy, which enhances the force-generating capability of the muscle-tendon complex. Therefore, sports scientists and physical therapists are interested in the behavior of tendons, such as the Achilles tendon, during movements such as running and jumping. Recently, imaging modalities, including ultrasonography and magnetic resonance imaging, have improved, enabling measurement of tendon length changes during muscle contractions in humans under certain physiologic conditions. With this situation in mind, first, the possible role of tendon length changes in force-generating capability of the muscle-tendon complex is introduced. Results obtained from animal studies also are included in this part.

Preface

ix

Second, methods to evaluate tendon length changes in humans, especially of the Achilles tendon, including ultrasonography, magnetic resonance imaging, and estimation equation methods, are described. Currently, these methods have been widely applied in the relevant scientific community. Finally, interpretation of the results obtained by using the above mentioned methods is provided. Because each method has some limitations, care should be taken when interpreting these results. Knowledge of these points would lead to better understanding of the behavior of tendons, and consequently, better understanding of the force-generating capability of the muscle-tendon complex. Chapter 3 - The Achilles tendon is a key structure separating humans from other primates, allowing the upright bipedal stance. There are many advantages to being a biped from hunting ability to energy expenditure. The Achilles tendon itself has the benefit of greatly enhancing endurance running. However, there are disadvantages to having an Achilles tendon such as its vulnerability to injury. This article outlines the advantages and disadvantages of the tendon and highlights some theories as to why humans may have evolved to have it. Chapter 4 - Ankle joint is one of the most complex joints in the human body. Anatomists, biomechanical engineers, and clinicians have studied the foot and ankle complex for centuries. Each discipline has provided its unique insight into the structure and function of this unit. The differences of approaches have also led to varying interpretations, resulting in considerable confusion regarding the operation of this complex. The purpose of this article is to discuss the basic biomechanical characteristics and forces acting on the ankle under static conditions and their influences on artificial total ankle replacement designs.

In: Achilles Tendon and Ankle Injuries ISBN: 978-1-63483-484-1 Editor: Arthur Adams © 2015 Nova Science Publishers, Inc.

Chapter 1

EFFECTIVENESS OF DIFFERENT PHYSICAL THERAPIES IN CONSERVATIVE TREATMENT OF ACHILLES TENDINOPATHY: SYSTEMATIC REVIEW Ana María Díaz López1, Daniel Gómez López2 and Patricia Guzman Carrasco3 1

Physiotherapist of Ntra. Sra. del Prado General Hospital, Spain Physiotherapist of Ntra. Sra. del Prado General Hospital, Spain 3 Physiotherapist of Villanueva de la Vera Health Center, Cáceres, Spain

2

ABSTRACT The prevalence of Achilles tendinopathy is unknown (although when considering the partial or complete ruptures is per 100,000 people the consequences of overuse). Its etiology is multi factorial, including increased weight bearing with the knee extension, sudden and violent dorsiflexion and direct trauma, as well as friction with the back of the shoes with high heels. If there is a bony prominence such as Heglund disease, rubbing intensifies and causes a chronic inflammatory painful process. Achilles tendinitis occurs most frequently in male than females by a ratio of 3:1 between the fourth and fifth decades of life. The clinic can be acute or chronic, the chronic understood by one with an evolution of more than 3

2

A. M. Díaz López, D. Gómez López and P. Guzman Carrasco months. According to the predisposing factors that act, the lesion is located at different levels of the tendon, there are insertional tendinitis and other non insertional. The treatment of choice for Achilles tendinopathy is conservative, being used ortostatic measures, shock waves, laser, ultrasounds, therapy with eccentric exercises, and other less common techniques such as pulsed light, massage of Cyriax, iontophoresis, acupuncture, among others. It is often combined with anti-inflammatory drugs and injections. Surgical treatment is usually not performed and involves extensive rehabilitation, 3 to 6 months prior to loading on foot. The aim objective of this study was to determine the effectiveness of various physical therapies in the conservative treatment of Achilles tendinopathy. Methods: A systematic review of scientific studies addressing the treatment of Achilles tendinitis was performed by physical agents. A search was conducted on the bases Web of Science, The Cochrane Library, Medline, Lilacs, IBECS, IME, PEDro and ENFISPO, This search was made in both Spanish and English without restriction at the time of the items, performing the last search in February 2015. Randomized controlled trials were included adult patients diagnosed with Achilles tendinopathy, intervention studies, prospective studies and systematic reviews. Assessment of study eligibility was developed by three reviewers independently and unblinded standardized. To classify the critical reading PEDro scale was used along with a critical review of each abstract first, and if this was not conclusive assessment of the full text. Results: After identifying 398 articles 23 articles were analyzed, 3 prospective study (n = 115), 2 case-control studies (n = 258) and 18 controlled clinical trials (n = 889) also were consulted 9 systematic reviews, as well as a Clinical Practice Guideline. Conclusion: This review presented a variety of physical treatment alternatives can be seen in the Achilles tendinitis. The only one that seems effective in isolation and that its effectiveness continues long term are eccentric exercises.

Keywords: Tendinitis, Achilles tendon, therapy, pain and physical therapy

INTRODUCTION The Achilles tendon is the thickest tendon in the human body. It is formed by the union of the tendons of the Soleus and Gastrocnemius muscles. It has

Effectiveness of Different Physical Therapies …

3

about 6 cm, a width of 12 mm and a thickness of 5 to 6 mm. Its function is plantar flexion [1, 2, 3] and due to the spiral arrangement of its fibers it is able to increase its extensibility releasing the energy needed for locomotion [4]. The prevalence of the injury is unknown (although considering the partial or complete ruptures the ratio is [10-37] per 100,000 people as a consequence of overuse) [1]. Its etiology is multi factorial, including an increasement on the weight bearing in the knee extension, sudden and violent dorsiflexion and direct trauma, as well as friction with the back of the high heels shoes. If there is a bony prominence such as Heglund disease, rubbing intensifies and causes a chronic inflammatory painful process [1, 2]. Achilles tendinitis occurs most frequently in male than females by a ratio of 3:1 between the fourth and fifth decades of life [1]. The clinic can be acute or chronic, being the chronic understood as one with an evolution of more than 3 months. According to the predisposing factors that act, the lesion is located at different levels of the tendon, there are insertional and non insertional tendinitis [3]. Sometimes an insertional tendinopathy is anterior to the tendon attachment on the part calcaneus of a widespread enthesopathy (ankylosing spondylitis, psoriasis, Reiter) [3]. The non insertional tendinopathy is called tendinosis. It appears on the weaker and less vascular tendon area, about 2-6cm cranial insertion into the calcaneus direction. Its cause is mechanical (pronation, club foot, varus tibia, arched feet with varus hindfoot, muscle hypertrophy) and it often occurs bilaterally being more common in the inner side than the outer. It is more common in young athletes [3]. The cause of Achilles tendinopathy (formerly called "Achilles tendinitis") is considered unnatural scar tissue which causes the tendon to weaken. A slow healing helps the blood supply to the tendon and it is often deficient in these cases [3, 5]. The pain appears in the middle of the tendon. At the beginning, the pain and the numbness generally occurs only in the morning, when performing the heating in case of athletes or after the activity. Resting sometimes decreases the symptoms, but these appears again with the increseamnet of the activity. In later stages, tendon pain is more constant and it can turn into a chronic pain [3, 6]. Clinically there is an indurated area over the Achilles tendon, more or less prominent, where deformity in the tendon is observed. The consistency is hard and can be very painful with palpation. Sometimes the change in the temperature is not detectable due to the poor vascularization of the tendon tissue. In peritendinitis fibrinous exudative formation on the surface of the tendon often appears resulting in a crackling form [2, 3, 5].

4

A. M. Díaz López, D. Gómez López and P. Guzman Carrasco

The clinical diagnosis is clear and can be seen through the practice of a nuclear magnetic resonance (NMR), but it is not necessary. Often an ultrasonography study is done, it is a less expensive and faster test that provides data about the inflammatory or regenerative state of collagen bundles, of the existence of a peritendinitis with increased serosity, or the evolution of process done [1, 3]. The first treatment for Achilles tendinopathy is conservative [3, 7], using ortostatic measures [8-11], shock waves [12-15], laser [16-19], ultrasounds [20, 21], therapy with eccentric exercises [9-13, 16, 18, 19, 21-27], and other less common techniques such as pulsed light [28], massage of cyriax [21], iontophoresis [29], acupuncture [27], among others [30]. It is often combined with anti-inflammatory drugs and injections. Surgical treatment is usually not performed and involves extensive rehabilitation, from 3 to 6 months prior to loading on foot [7]. Currently, few studies have evaluated the effectiveness of physical therapies in the conservative treatment of Achilles tendinitis. There are few clinical practice guides on the subject and scientific studies are scarce. Therefore the aim of this review is to determine whether there is scientific evidence on the effectiveness of different physical therapies in the conservative treatment of Achilles tendinitis. The aim objective of this study was to determine the effectiveness of various physical therapies in the conservative treatment of Achilles tendinopathy.

MATERIAL AND METHODS Design A systematic review of scientific studies addressing the treatment of Achilles tendinitis was performed by physical agents.

Search Strategy A search was conducted on the Web of Science Library, Medline, Lilacs, IBECS, IME, PEDro and strategy search descriptors (MeSH) tendinitis, Achilles and physical therapy. This search was made in both

basis, The Cochrane ENFISPO, using as tendon, therapy, pain Spanish and English

Effectiveness of Different Physical Therapies …

5

without restriction at the time of the items, performing the last search in February 2015. To search for original studies the Medline database was consulted using the following equations search: "Achilles tendon" [MeSH] AND "physical therapy specialty" [Mesh], treatment AND "Achilles tendon" [Mesh]. The search was not just limited by year of publication although language limit was introduced as the language of the studies was English or Spanish. The references of the items selected in order to include other potentially valid studies for review were also analyzed. Priority was given to studies and clinical trials about different conservative techniques in the treatment for Achilles tendinopathy either individually or combined with each other techniques.

Inclusion and Exclusion Criteria The evaluation of the eligibility of the studies was developed by three independent reviewers in an unblinded standardized manner. The critical reading PEDro scale was used along with a critical review of each summary first to classify, and to those whose abstract was inconclusive assessed the full text. In case of disagreement among reviewers it was resolved by consensus. The PEDro scale consists of 11 items (the first was not taken into account in the evaluation), which assess the methodological quality of randomized controlled trials giving priority to two points: the internal validity and the inclusion of statistical data provided for the interpretation of results. Moseley et al. [31], indicated that studies with a score equal to or greater than 5 are classified as high methodological quality and low risk of bias. Inclusion criteria of patients were the following: being over 18 years and diagnosed with unilateral or bilateral tendinopathy of at least two months' duration. Exclusion criteria were taken into account; the subjects did not suffer rheumatic or inflammatory diseases, congenital or acquired deformities of ankle and knee both anterior surgical treatment of ankle or Achilles tendon or rupture of the tendon. The treatments included in the review were: • •

Stretching programs, stretches and eccentric exercises [22-26]; Eccentric exercises programs combined or compared with other therapeutic modalities: shock waves [12, 13], ultrasounds [20],

6

A. M. Díaz López, D. Gómez López and P. Guzman Carrasco

• • • •

orthopedic braces [9-11] combined conservative therapies (US, Cyriax and stretching) [21], laser [16, 18], acupuncture [27]; Shock waves therapy [14, 15]; Treatment with orthopedic braces or splints [8]; Laser treatment [17, 19]; Treatment with other less conventional therapies such vibrating platform [30], iontophoresis [29] or using pulsed light [28].

Exclusive pharmacological and surgical treatments were excluded. Studies comparing conservative treatments and surgical treatments that were not published in English or Spanish were also excluded. In addition the results of previously published reviews were taken into account.

Data Extraction Three investigators identified individually potentially eligible to fulfill the inclusion criteria studies. For collection of relevant data for the study ad hoc a template to facilitate the assessment was designed by the researchers themselves. In case of disagreement this was resolved by consensus among the team members.

RESULTS After identifying 398 articles 23 articles were analyzed, 3 prospective studies (n = 115), 2 case-control studies (n = 258) and 18 controlled clinical trials (n = 889) also were consulted 9 systematic reviews [7, 32-39], as well as a Clinical Practice Guidelines [40] (Figure 1). In the 18 trials reviewed, the average score on the PEDro scale was 8,3 points. One controlled clinical trial [19] received the highest score (10), the lowest score was for a trial [11] with a score of 6 above the required minimum that was set on 5 (Table 2). The two case-control studies reviewed [15, 23] obtained a score of 6 and 7 respectively while three prospective studies [14, 20, 21] reached a score of 6, 7 and 6 (Annex 1) as the methodological quality criteria used to evaluate studies intervention and prospective.

Effectiveness of Different Physical Therapies …

7

Figure 1 Number of items identified by searching databases (n = 391) +Web of science (n=45) +MEDLINE (n= 206) +ENFISPO (n= 12) +PEDro (n= 13) +IME (n=1) +IBECS (n=1) +LILACS (n= 113) +COCHRANE (n= 6)

Articles excluded (n=59) +Surgery treatment (n=20) +Others (item about diagnose or pharmacology treatment) (n=30) +Language (n=9)

Items identified in other sources (n = 7)

Number of items after removing duplicates (n= 214)

Items excluded (n=16) +PEDro scale <5 (n = 2) +Case control studies (n = 1) +Name (n=7) + Full text (n=6)

Articles included for analysis full text

(n= 23)

+ Items included in the qualitative synthesis (n= 23) RCT (n=18) Prospective Studies (n=3) Case-Control Studies (n=2) +Systematic review (n=9) +Practice clinic guidelines (n=1)

Figure 1.

Characteristics of the Population The total number of subjects studied was n = 1.256 in total, with an age between 18-72 years, with a higher percentage of men over women. In three studies [9, 18, 30] the participants were athletes and in other study [17] all participants were required to have bilateral involvement. Regarding the variables of the subjects, the time evolution of tendinopathy are grouped in > 2

8

A. M. Díaz López, D. Gómez López and P. Guzman Carrasco

months [22, 27], > 3 months [8-12, 19-21, 23-29], > 6 months [6, 13, 15, 30]. Another variable in the population studied was the diagnostic method of the tendinopathy, which mostly relied on the history and physical exploration [812, 15, 16, 19-21, 24-27, 29, 30], only a ultrasonography [10, 13, 28],few used the echo Doppler [8, 17] or algometer [17].

Data Analysis The main scale used to assess pain and functionality was VISA-A [8, 9, 13, 16, 18, 19, 21, 22, 24-28]. This VISA-A questionnaire (Victorian Institute of Sport Assessment-Achilles) is a subjective scale that quantifies the symptoms and dysfunction Achilles tendon [41] is useful to assess the Achilles tendons and to assess the progress of the recovery during rehabilitation [42]. To assess pain Visual Analog Scale (VAS) [10, 12, 15, 16, 18-20, 23, 24, 26, 27, 29, 30], the NRS scale [13] (pain induced charge), the scale Foot and ankle outcome score (FAOS) [11], and scales type Likert [13, 30]. To measure the patient's functionality and ability to perform activities of daily living, some of the secondary outcome measures used were: LEFS scale [28], Single jump hop test [17], FILLA [20], American Orthopedic Foot and Ankle Society scale (AOFAS) [10, 12], Roles and Maudsley scale [14, 15]. For other secondary outcomes such as patient satisfaction or general health status were used: the questionnaire EUROQOL [20], Tegner [24], the health scale SF-36 [10], satisfaction survey [9]. Some of the instruments used for diagnosis were: algometer [17, 19], quantitative measurement of the thickness of the tendon through Doppler sonography [8, 17], ultrasonography [30] and toughness to palpation and inflammation [23]. The follow-up time was 6 weeks [26], 12 weeks [9, 13-15, 17, 18, 20, 21, 29, 30], 24 weeks [27] and one year [8, 10-12, 16, 19, 23, 28] after completing treatment. Table 1 shows the characteristics of each of the 23 studies included in this review classified with the name of the first author, publication year, sample size, type of study, technique, treatment performed and summary of the obtained results, with rating scales and statistical data used. Grouping the studies according to the techniques used, eccentric exercise programs were the most common (42.42%). In this technique the most used exercises were based on the work of Stanish [42] and Alfredson [43]. Stanish [42] was first proposed in 1986, a program of eccentric for each of the most common tendinosis exercises, including the Achilles tendon.

Table 1. Characteristics of each of the 23 studies AUTHOR

SUBJECTS

Stevens M. [26] 2014

28 subject

STUDY DESIGN RCT

TÉCHNIQUE

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

Eccentric exercise.

G1 = protocol Alfredson * = 15 G2 = the repetitions that the patient tolerates = 13 * Alfredson Protocol 180 repetitions / day drop in eccentric heel.

It assesses and compares the score scales VISA-A and EVA at 3 and 6 weeks, using factor analysis of variance mixed. Satisfaction with treatment was assessed at 6 weeks. The statistical program used was SPSS statistical mean 17. It was used as Chi-square test with Yates to analyze the association between satisfaction participants and the respective groups treatment. The differences in the number of repetitions per day groups were analyzed using the MannWhitney test. It was significant improvement in scores on the VISA-A level in both groups (p = 0.03 GE, GC p < 0.01). In the relationship between the scores between the two scales VISA-A EVA and there was statistical significance at 3 weeks both intention to treat analysis (p = 0.004) and protocol analysis (p = 0.007) There was no statistical significance at 6 weeks in scoring in both scales. It was significant that there was more satisfaction with the treatment in the control group but there is no relationship between this satisfaction and treatment received. There is also no correlation between the treatment received and the values on the questionnaire VISA and EVA (τ = 0.28, p = 0.09 and τ = -0.27, p = 0.10, respectively). No significant differences in the performance of one or another treatment to improve tendinitis middle portion of Achilles.

Table 1. (Continued) AUTHOR

SUBJECTS

Roos EM. [11] 2013

45 subject

STUDY DESIGN RCT

TÉCHNIQUE

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

+ Eccentric exercise + Previous night splint with foot in dorsiflexion.

Subjects with pain in the middle portion of the Achilles tendon. The exercises were 3x15 repetitions of eccentric Achilles with extended and flexed knee. 12 weeks of follow-up 3 groups. G1 = 1 group performing eccentric exercise = 16 G2 = 1 group using night splint = 15 G3 = both techniques = 13

Pain and function were assessed by the Foot and Ankle outcome score. It was applied at baseline, 6, 12, 26 and 52 weeks. Intended for treatment of patients was taken into account. The changes were observed by Friedman's test. If this was significant the data with the start using the Wilcoxon test were compared. The Kruskal-Wallis test was used to compare the 3 groups and the Mann-Whitney U test to compare two groups. W2 test was used to compare proportions. At 6 weeks there was a significant reduction of pain in the group that worked on eccentric, up 27% from baseline (p = 0.007) which lasted for one year (p = 0.001). The two groups had used the night splint reduced pain but smaller than the group that worked on eccentric tendon. The differences between the three groups were not significant. At 12 weeks the working group with eccentric contractions had much less pain than the group that only used the night splint (p = 0.04). Most of the subjects of the working group on sports eccentric again before 12 weeks. The study reinforces the previous idea that should implement a program of work in eccentric before other treatment options.

AUTHOR

SUBJECTS

Horstmann T. [20] 2013

58 patients athletes

STUDY DESIGN RCT

TÉCHNIQUE

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

G1 = whole body vibration vibrating platform = 23 G2 = eccentric tendon training = 19 G3 = Treatment expectant = 16

36 sessions vibration and eccentric tendon training were applied to each group. In the expectant group was no specific job tendon. All individual sessions conducted by preference recreational activities (housework, social activities, recreational activities and running).

Pain, tendon structure and PATH, muscle flexibility and strength at the beginning and end of treatment were measured. 12 weeks of follow-up. Tendon structure was analyzed by ultrasound, using a Likert pain and VAS (both in daily life and tenderness), pain location (on insertion of the tendon middle 2cm above the insertion scale myotendinous in union) and the force was measured with a computerized system chassis. Statistical analysis was performed using SPSS 19.0.0 system. Factor mixed analysis of variance. About pain, eccentric working group had more pain than the vibration group (p = 0.026). The improvement in pain in the middle was higher in the two working groups (vibration and eccentric work) than in the expectant group (-18.0, 95% [CI]: -35.0, -1.1 and -27.0; 95% CI: -50.9, -3.1, respectively). The reduction in the palpation tenderness was higher in the group of eccentric work in the vibration group (main difference in the vibration group -31.4; 95% CI: -60.7, -2.0; main difference -50.2 expectant group; 95% CI: -82.3, -18.1) There were changes in the structure especially in groups of vibration and eccentric work but there was no difference between the time and intervention (p> 0.05) As for the strength in both groups had more resistance in the higher ankle dorsiflexion was (p < 0.001). The two techniques (vibration and eccentric work) improve pain in the middle of the tendon, but only eccentric exercises improve pain in the muscle-tendon junction. As for changes in the structure and strength results with both techniques are similar. Vibration therapy can be complementary to an eccentric work and even an alternative when pain is insertional.

Table 1. (Continued) AUTHOR

SUBJECTS

De Vos RJ. [9] 2004

70 subject athletes

STUDY DESIGN RCT

TÉCHNIQUE

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

+ Night splint.

G1 = night splint and eccentric work = 36 G2 = eccentric work = 34

Patient satisfaction was assessed and they used the VISA-A questionnaire to pain. The patients had pain in the middle of the tendon. 12 weeks of follow-up The Wilcoxon test was used to show changes over time of variables between the groups and the Mann Whitney is used to detect changes between the two groups. The X2 test was used to assess patient satisfaction and compliance of the two groups. It was assumed to be statistically significant if p < 0.05. At 12 weeks the satisfaction was higher in group 2. The VISA-A questionnaire improved in both groups. G2 improved from 50.1 to 68.8 (p = 0.001) and in addition to exercise G1 increased from 49.4 to 67.0 (p < 0.001). Linking groups is not much difference or VISA-A (p = 0.082) or patient satisfaction (p = 0.26). Therefore the use of night splint to complement the eccentric work tendon not improves midportion Achilles tendinopathy.

+ Eccentric work tendon.

AUTHOR

SUBJECTS

Petersen W. [10] 2007

100 subject

STUDY DESIGN RCT

TÉCHNIQUE

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

Eccentric work splint AirHeel

G1 = 1 workgroup eccentric tendon = 37 G2 = 1 group using the splint AirHeel = 35 G3 = 1 group combined the two techniques = 28

Three groups of intervention were assessed at 6, 12 and 54 weeks. Pain by EVA, the scale for the ankle and foot of the AOFAS and the state of health by SF-36 was assessed. For statistical analysis the StatView 5.0, SAS Institute, Cary, NC commercial software was used. In the three measurements at follow-up there were no significant differences among the 3 groups, in all there were no differences in the thickness of the tendon during treatment. In the AOFAS scale improvement occurred throughout all measurements of monitoring, even after a year improved to ten points in the eccentric training group and up to 12 points in the group using both techniques (p < 0.001). The pain also improved in all three groups being significant than a year in all the decline in the group combined the two techniques (p < 0.001) had improved is even higher AirHeel conclude that the splint is as effective as exercise therapy, eccentric, but we found no evidence that the combination of both will improve over the results.

Table 1. (Continued) AUTHOR

SUBJECTS

Grävare K. [22] 2007

38 subject 51 tendons

STUDY DESIGN RCT

TÉCHNIQUE

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

Tendon normal work: jump, run. Specific activity resting tendon

G1 = tendon after normal activity (jumping and running) = 19 G2 = tendon rest for 6 weeks, a group of active rest = 19 The training schedule was identical except in those specific rest 6 weeks tendon.

Two intervention groups. Specific activity and rest for 6 weeks. The follow up to 6 months. Achilles scores functionality in the Swiss version of the VISA-A and EVA pain were evaluated. They were measured at 6 weeks, 3, 6 and 12 months. Groups were compared using the Mann-Whitney U test at the beginning and end. To assess improvement from baseline Wilcoxon test was used. Spearman correlation coefficient was used to assess the correlation between the improvement in symptoms and severity and duration of symptoms. The results were obtained in standard deviation. There were no significant differences in improvement in both groups, but both improved in relation to the initial evaluation (p < 0.01). At twelve months, the group that performed exercise had an improvement in VISA-A score of 57-85 at 12 months follow-up (p < 0.01). In the group of active rest improved VISA was 57-91 in scoring at 12 months follow-up (p = 0.01). The work of the specific tendon does not have a negative impact on the recovery of the Achilles tendinopathy.

AUTHOR

SUBJECTS

Tumilty S. [16] 2012

40 subject

STUDY DESIGN RCT

TÉCHNIQUE

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

+Low intensity laser therapy +Eccentric exercise program tendon

G1 = program therapy exercises and laser = 20 G2 = exercise program and placebo = 20 Exercise Program: 6 sets of 15 repetitions of eccentric, unilateral, twice a day, 7 days a week for 12 weeks. Laser method standardized 3-point contact on either side of the Achilles tendon (6 points in total, 2cm proximal and 2 distal lesion centimeters), 30 sec at an intensity of 18J/point 3J/session, 3 times/week.

Scores were evaluated in VISA-A scale and the EVA. Data were analyzed by ANCOVA Covariance analysis. Both participants and therapists were blinded. Measurements at baseline, 4, 12 and 52 weeks were performed. They completed the study at 52 weeks 17 subjects in the G1 and in G2 16. The analysis of data at 4 and 12 weeks were analyzed by physiotherapists blinded, at 52 weeks was evaluated by questionnaire by mailing. As for the results in the VISA-A scale at 4 weeks there was better data in the placebo group (p = 0.016), the remaining data were not significant. As to the difference pain throughout the week it was not significant, being better scores in the placebo group. The correlation between the score on the VISA-A and the pain is not significant or 4 (p = 0.131) or at 12 (p = 406), or at 52 weeks (p = 0.097). The study does not demonstrate the potential benefits of low level laser with a program of eccentric exercises for the treatment of Achilles tendinopathy.

Table 1. (Continued) AUTHOR

SUBJECTS

De Jonge S. [8] 2012

70 tendons 58 patients

STUDY DESIGN RCT

TÉCHNIQUE

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

G1 = 34, was applied eccentric exercise program. G2 = 36, night splint rest of Achilles and eccentric exercise program.

VISA score on the scale, the degree of patient satisfaction and neovascularization with Doppler ultrasound was measured. At baseline, 3 months and a year. SPSS 12.0 software and Chi-square test was used for statistical analysis. As for the score on the scale VISA-A improved in both groups but no significant differences relating both groups or the start a year (p = 0.36) or three months to one years (0.24). There were no differences in morning stiffness (although improved) at baseline (p = 0.19), at 3 months (p = 0.09) and years of follow-up (0.12). So does patient satisfaction, although improvement in both groups no statistical significance (p = 0.20) As neovascularization no significant differences relational VISA-A score with patients having or not new vessels at baseline (p = 0.71). This study does not prove the efficacy of the night splint with eccentric exercise.

AUTHOR

SUBJECTS

TÉCHNIQUE

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

20 subject

STUDY DESIGN RCT

Tumilty S. [19] 2008

+ Laser low frequency (LLLT) + Eccentric exercises

Experimental group: 12 weeks of eccentric exercises (2 times/day) + LLT (3 times/week) by 6 points, 3 J/sec point during 6. Total 18 J/session Placebo group: 12 weeks of eccentric exercise program twice/day + placebo laser.

48 subject

RCT

+ Shock-waves (ESWT) + Stretching exercises and eccentric

Experimental group: 4 sessions shockwaves 2000 pulses (0.12 to 0.51 mJ / mm2, 50 Hz) over 4 weeks + stretching exercises and eccentrics. Placebo group: Application of shockwaves 2000 pulses (0 mJ / mm2, 50 Hz) 4sessions/4 weeks + stretching exercises and eccentric.

An evaluation was conducted initially, at 4 weeks and 12 weeks, using VISA-A, the VAS for pain and stretch Biodex dynamometer for isokinetic scales. Statistical analysis was performed using SPSS version 14.00 program, performing the analysis of covariance (ANCOVA) At first there were no differences between groups were observed in both groups was observed p < 0.005 significant both 4 and 12 weeks unless p = 1,11en the placebo group at 4 weeks in the offset measurement stretch. The difference between the two groups was not significant (you cannot see the effectiveness of LLT) which may be due to the low number of subjects even if it is proved the effectiveness of eccentric exercises. Before and after the treatment, then 4, 8 and 12 weeks post treatment making use of the AOFAS scale and VAS assessment. Stata 9.2 program by a study of variance and T-test was used Bonferoni. It was considered P < 0.05 statistically significant and analysis of covariance to three months follow with 95% confidence interval Experimental group improved compared to P = 0.05 at the end of treatment control group was obtained in the result of the AOFAS scale, improving 8 more with P = 0.01 at 12 weeks P = 0.04. The best results were obtained in women after three months of completing treatment For pain both groups improved finding no significant difference between groups.

Rasmussen S. [12] 2008

Table 1. (Continued) AUTHOR

SUBJECTS

Verrall G. [23] 2011

190 subject

STUDY DESIGN Retrospective case-control study

TÉCHNIQUE

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

Eccentric exercise program with stretching maintained at least 15 seconds.

G1 = tendinitis insertional = 14 G2 = average tendinitis no inflammation = 21 G3 = average tendinitis inflammation = 121 Exercise program, 6 levels: Level 1: 1 series with both legs 1 once daily. Level 2: 1 series with both legs 2 times a day. Level 3:1 series with both legs 3 times daily. Level 4: 1 series with a leg affected, 1 time a day. Level 5: 1 series with a leg, 2 times a day. Level 6: 1 series with a leg 3 times daily.

Patients were evaluated at 2 and 6 weeks only to those who required, at 12 weeks was assessed at all and at 6 and 14 months at all. At the end of these six weeks could progress in doing exercise and even return to physical activity. If they were not able to return to sport after reaching level 6 is exercise, were given a pattern of eccentric exercises of greater intensity. VAS was used to assess pain, tendon hardness also tenderness and swelling was studied. Measures at baseline and at 12 weeks were compared and compared using the Wilcoxon test. Statistical significance was set at p < 0.05. The data at 6 and 14 months were collected by phone. They were also asked to rate how effective the treatment on a scale of 0-10 and if they had to be surgically operated on or if they continued with eccentric exercises. In the mean VAS score it was 7 at 12 weeks reduced by 2.9 (p < 0.01) and at 6 and 14 months was reduced 1.1, on average 0 (p < 0.01). Scores are classified according to the location of pain and whether there was inflammation in the middle of the tendon. There was improvement on the VAS at all locations. In the beginning, G1 scored 7.3, 3 after treatment and they had to be operated three of these 14 patients. In G2 they scored an average of 6.9 on the VAS at baseline and at the end thereof 3.6. They had to be operated three of these patients. In G3 121 patients with pain in the middle of the tendon and inflammation. They scored an average of 7.3 at

Hutchison AM. [28] 2013

47 subject

RCT

Intense pulsed light (IPL)

Experimental group: 3 IPL sessions (from 530 to 1100nm, 13J / cm2). Control group: the same treatment but without the machine running

baseline to 2.8 at the end of it. She had to undergo surgery 1 of these patients. In all groups when asked about the satisfaction they scored above 6, (8.0 highlights in the middle group with inflammation). There is an improvement in all groups being lower in the insertional group. The improvement was observed in pain, satisfaction, return to activity and fewer surgeries. VISA-A, the LEFS scales to assess the functionality and VAS pain scale at the beginning at 6 and 12 weeks after treatment were used. At first the tendon was examined by ultrasound to measure the thickness, this was repeated at twelve weeks to finish to make a quantitative comparison. Statistical analysis was conducted using SPSS software v.13.0, the t-test and The Mann-Whitney U test The difference between the two groups in any of the scales used was not significant at six to twelve weeks of followup. In ultrasonography studies no significant differences at P = 0.769 sectional view is found and P = 0.942 in the longitudinal improvements were seen or vascular or tendon regeneration level.

Table 1. (Continued) AUTHOR

SUBJECTS

Stergioulas A. [18] 2008

52 subject (atletas amateur)

Bjordal JM. [17] 2006

7 subject (Tendinitis bilateral, total = 4)

STUDY DESIGN RCT

RCT

TÉCHNIQUE

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

+ Laser low frequency (LLT) + Eccentric exercises (EE). + Stretches the sural triceps

Experimental group: + Eccentric exercises. + 12 LLT sessions (60mW/cm2 5.4J/session) applying in 6 points of the tendon over 8 weeks. + Stretching the sural triceps. Control group: + Eccentric exercises + LLT + Placebo. + Stretching the sural triceps. 2 sessions/week in the first 4 weeks and then 1 session a week is applied during the second 4 weeks.

Assessments of pain with VAS (100mm) at first, at 4, at 8 and 12 weeks were performed. The scale was also used VISA-A For statistical analysis the SPSS version 14.0 software was used, a level of significance P = 0.05 was considered. Roasted himself conducted the analysis covariance.

+ Laser low frequency (LLT)

As patients had bilateral tendinitis, considered in each case would be a stub and the other would control Experimental group: 1 session LLLT of 5000Hz at three points along the tendon for 3 minutes

Pain intensity during exercise

4 week

8 week

12 week

Experimental G. Control G. P

53.6 mm 71.5 mm 0.0003

37.3 mm 62.8 mm 0.0002

33.0 mm 53.0 mm 0.007

In the morning pain, active dorsiflexion, palpation of the tendon and crepitus showed the same pattern for the experimental group LLT applying accelerates the recovery process since the results of the experimental group at 4 weeks were similar to the control group at 12 weeks To assess pain was used to average three test with pain algometer pressure (Preassure pain threshold PPT) functionality test jump with one leg (Single hop jump test), tendon thickness was measured with calipers calibrated and structural alterations with Doppler. Results after treatment Doppler Less inflammation due to increased blood flow in 14 tendons and the like in 8 (95% CI)

AUTHOR

Rompe JD. [13] 2008

SUBJECTS

68 subject

STUDY DESIGN

RCT

TÉCHNIQUE

+ Program eccentric exercise + Shock waves of low frequency (SWT)

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

(5.4 J in total, 20 mW / cm2). Control group: placebo LLLT session (0J) in the same manner as in the experimental group

Results after treatment Prostglandins Decrease at 75, 90 and 105 min. in the experimental group compared to baseline P = 0.026 and in the control group P = 0.009 Pain threshold Significantly compared to the control pressure group P = 0.012 (95% CI) was increased in the experimental group For different assessments the VISA-A, Likert scales and scale of load induced pain (NRS) were used. To analyze continuous variables standard, median and mean deviation was used. The variables between groups were evaluated with the percentage. To compare the results of the Visa-A scales and NRS from principle and 4 months the Wilcoxon test was used and for comparison between groups analysis of variance.

Experimental group: + Eccentric exercise program: It started with a series of 10 repetitions /1 day progressing gradually to 3 sets of 15 repetitions on the 7th day to complete 3 sets of 15 repetitions / 2 times a day to the 2nd week and continuing it until 12 weeks / 7 days week. Charge progressive multiples of 5 kg. + Shockwaves (SWT): From the 4th week 3 sessions shockwaves 1 / week 2000 pulses (0.1 mJ / mm²). Control group: the same program that the experimental eccentric exercises.

4º month of treatment VISA-A

Experimental Group 2:87 + 16

Control Grupo

P*

1:73 + 9

0,0016

E. Likert (Complete recovery) NRS

82%

56%

2:6,8 + 0,9

1:7.0 + 0,8

0,0045

*P: patients in the experimental group performed better by making the comparison between groups One year after treatment, the differences between the two treatments had not changed significantly compared to the first evaluation.

Table 1. (Continued) AUTHOR

SUBJECTS

Ram R. [24] 2013

48 adults: +Group 1: 20 con Achilles tendinopathy +Group 2: 7 without tendinitis +Group 3: 21 control without tendinitis

STUDY DESIGN RCT

TÉCHNIQUE

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

+ Exercise program based protocol Alfredson eight stretches followed by genuflection and ankle jumping and lifting.

All groups had to perform a series of exercises with the knee in extension followed another series of knee and ankle slightly flexed, 3 sets of 15 repetitions respectively. 12 weeks. G1: to see the effectiveness of the treatment. G2: the effect of exercise on healthy tendon was evaluated. G3: the possible change was measured in the color Doppler (vascularization of the area)

The results were measured first by the degree of patient satisfaction, an initial assessment was made with Vas, VISA-A and Tegner scales and a study by doppler. Statistical analysis was performed using Stata program 10.Intervalo 95% confidence and the P value. For satisfaction the binomial probability test was used. Comparison from 0-12 weeks VISA-A Score VAS (tendon loading) VAS (ADL)

Tegner scale

Satisfied (n = 2)

No Satisfied (n = 18)

P

28.5 (-28.68, 85.68) -50.5 (-310.98, 209.98) -15 (-205.59, 175.59) 2.5 (-29.27, 34.27)

16.78 (6.31, 27.25)

0.4533

-22.22 (-37.14, -7.30)

0.2213

-8.11 (-19.24, 3.02)

0.6837

0.33 (-0.62, 1.28)

0.1702

AUTHOR

SUBJECTS

Stanisopoulos D. [25] 2013

41 subject +21 stanish group +20 Alfredson group

STUDY DESIGN RCT

TÉCHNIQUE

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

+ Program eccentric exercises and stretching according Stanish

Stanish Group: Exercise program of 5 steps: General 1.Heating. 2. Stretch sural triceps flexion and extension. 3estretches of 30 seconds and 60 seconds of rest. 3. 3 sets of 10 repetitions of eccentric exercises 1time a day in the first 6 weeks and then three times a week until the 12th week. 4. Exercises like to step 2. 5. Ice 5-10 minutes.

The degree of pain of functionality and the degree of neglect was measured. These assessments were performed at the beginning, at the end of treatment (12 weeks) and 6 months of completing treatment. For this, the VISA-A scale was used. For statistical analysis, independent t-test for between-group analysis was used and to compare between the beginning and end of treatment, the paired t-test was used. The statistical program was the SPPS 11.5 and a significance level of P = 0.05

Alfredson Group: Eccentric exercise at low speed 2 times a day, 7 days a week for 12 weeks. They were held in flexion and knee extension. All exercises in three sets of 15 repetitions with two minutes of rest between sessions.

The improvement between 12 to 36 weeks between groups was P < 0.05 in t-test depent. The conclusion is therefore that the exercise program based on the model of Alfredson was increased to reduce pain and improve function from the model Stanish, both at the end of treatment and follow-up.

+ Eccentric exercise program as Alfredson

VISA-A principle

12 week

G. Stanish 37 (95% CI 26-49) 25

G. Alfredson 37 (95% CI 26-49) 40

P p > 0.05 independent t -test; p < 0.05 paired t -test;

Table 1. (Continued) AUTHOR

SUBJECTS

Saxena A. [14] 2011

60 subject Heels 74

STUDY DESIGN prospective study

TÉCHNIQUE

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

+ Pulsed shock waves

3 sessions of 2500 shockwave impulses (2.4 bar, 11 to 13 Hz) 1/week

To assess the quality of the activities of daily life he was used at the beginning and the years after treatment the Roles and Maudsley (R & M) scale. The statistical program used was Systat 13, the statistical significance was defined P < 0.05 as well as the T-Student. R&M Paratendinosis n = 32 (43,24%) Tendinosis n = 23 (25,68%) insertional tendinopathy n = 19 (25,68)

Furia J. [15] 2008

68 subjects with no insertional tendinopathy

Casecontrol study

+ Shockwaves SWT (focal). +Conservative therapy

Experimental group: Single dose anesthetized SWT with 3000 pulses (0.21 mJ/mm2 Total 604 mJ/mm2) distributed in an area of 2-4cm. It started at a low intensity (200 pulses) and the remaining high intensity (2800) Control group: Each subject received one of the conservative therapy (rest, stretching, eccentric exercise, iontophoresis, splints…) for 6 months

Pre.Tto 3.22 ± 0.55 3.39 ± 0.5 3.32 ± 0.58

Post tto 1.84 ± 105 1.57 ± 0.66 1.47 ± 0.7

P < 0.0001 < 0.0001 = 0.0001

improvement n = 24 (75%) n = 18 (78.26) n = 16 (84.21)

The scales used were the Role and Maudley and VAS. For statistical analysis, the t-test and analysis of covariance was used to compare both groups. We considered p < 0.05 as significant, the statistical program used is the SAS version 8.2. Escala Vas Start 1 month 3 months 12 months

Experimental G. 8.2 4.4 2.9 2.2

Control G 8.4 8.4 6.5 5.6

P <0.001 <0.001 <0.001 <0.001

Scale R & M: the chi-square analysis showed that the percentage of patients with a score of excellent or good (positive) to both the 1, 3 and los12 months after treatment was statistically better in the experimental group than in the control group p < 0.001. No patient in both groups worsened comparing the scores at the beginning.

AUTHOR

SUBJECTS

Netter C. [29] 2003

25 subject

STUDY DESIGN RCT

TÉCHNIQUE

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

+ Dexamethasone iontophoresis +Saline iontophoresis

Experimental group: iontophoresis with dexamethasone (3ml) = 14 Control group: saline iontophoresis (3ml) = 11 Both groups performed the same exercise program for 10 weeks including: eccentric exercise, concentric and stretching of the Achilles tendon.

They were evaluated before and after 2 weeks and at 6 weeks, 3, 6 months and 1 year. Range of motion, tenderness and toe-raise test was evaluated. Pain during exercise, during the walk and climb stairs, and stiffness and swelling in the morning was assessed by questionnaire. To evaluate the effectiveness of treatment ANOVA, Wilcoxon, MPSR-T test and Mann-Whitney tests. The questionnaires were evaluated with the test of Friedman's. Fisher's exact was used to test the differences between groups. Significant value occurred when p = 0.05. Pain during activity decreased in both groups and after the activity was significantly decreased in the experimental group. At 6 weeks and 6 months it is significantly decreased pain in the dexamethasone, which also showed improvement when going up and down stairs at 6 months. As inflammation had improvements in both groups but was not in stiffness. Despite the small sample size it appears that the use of iontophoresis dexamethasone may be effective for the treatment of acute disease.

Table 1. (Continued) AUTHOR

SUBJECTS

Chester R. [20] 2008

16 subjects (2 bilateral, n = 18) Men 11 Women 5

STUDY DESIGN Study prospective

TÉCHNIQUE

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

+ Ultraso-unds. (US) + Eccentric load exercises

Group 1: Alfredson program, knee flexion and extension. All exercises in 3 sets of 15 repetitions with 1min rest between sessions. Once a day, 7 days/ week. Group 2: 2sessions/week pulsed US 2:8, 3MHz to 0.5W/cm2 for 2min/cm in the painful area inflamed tendon during (or before six weeks, if the pain or symptoms disappear worsen)

Patients were evaluated at 2, 4, 6 and 12 weeks from the start of treatment. The scale used for pain was VAS, to evaluate functionality and lower extremity leg (FILLA) was used and to evaluate satisfaction and overall health 5 questions of the general health questionnaire (EuroQol). These last two scales were evaluated together with a confidence interval of 95% were used. Pain in the ultrasound group improved during the first six weeks while in the 12 weeks the pain got worse at rest and in activity. In the exercise group, there were no marked differences in the results gradually decreasing. Functionality: In group ultrasound positive results were obtained in all assessments from the beginning to the 12th week. In the exercise group improvement was observed from 2- 12 weeks. Comparing both groups, differences significant statistics was not found in efficacy

AUTHOR

SUBJECTS

Herrington L. [21] 2007

25 subject

STUDY DESIGN Study prospective

TÉCHNIQUE

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

+ Eccentric exercises as Alfredson programs and Stanish.

Control Group: Cyriax massage lasting 15 minutes + continuous US 1.0 w / cm2, 1 MHz in the painful tendon area for 5 minutes. In total there were 6 sessions, 1 / week. They were also indicated a series of stretching exercises for knee flexion and extension to perform for 12 weeks once a day. Experimental group: Same treatment as control group, adding an eccentric exercise program three sets of 15 repetitions to continue for 12 weeks, to perform twice a day seven days a week.

It was held a 2x4 ANOVA (type of treatment and duration of the same, to analyze the effect over 12 weeks. The t -test was used to compare results with P < 0.001. The statistical program used was SPSS. Version 10. The scale used was the VISA -A at baseline at 4, 8 and 12 weeks.

+ Stretching exercises. + Ultrasounds. (US). + Deep transverse Massage (Cyriax)

Results VISA-A

4 weeks

8 weeks

12 weeks

Experimental G Control G P

30,4 9,7 0,01

15,8 12,8 0,01

5,6 9,4 0,01

Total Improvement (%) 51% 31,9% 0,01

All subjects were significantly improved after 12 weeks of treatment P < 0.01 as the result of VISA -A scale. We conclude that adding a program of eccentric exercises 12 weeks is more effective than treatment with US, Cyriax and stretching.

Table 1. (Continued) AUTHOR

SUBJECTS

Zhang B. [27] 2013

64 subject

STUDY DESIGN RCT

TÉCHNIQUE

INTERVENTION

TYPE OF IMPROVEMENT (OUTCOMES)

+Acupuncture treatment + Eccentric exercises.

Experimental group: 4 needles (0.35 mm in diameter and 40 mm long) were applied along the painful area with an inclination angle of 15 ° for 30 minutes, 3 / week quadrant times 8 weeks. Control group: eccentric exercise program in both length and knee flexion starting with 2 sets of 15 repetitions / meeting increasing a number more in each session.

VISA-A scale was completed at first, 8, 16 and 24 weeks. Pain at rest and after activity was evaluated at the beginning and at 8 weeks with the VAS scale. The t-test for continuous variables and Chi square for dichotomous and the Wilconxon intergroup comparison method was used. The statistical program used was SPSS version 16.0. Results VISAA 8ª week 16ª week 24ª week

Experimental G.

Control G

67.1 25.8 28.4

48.5 10 16.6

Results VAS at 8 weeks Experimental G Control G

Pain at rest

Pain after activity

-3.2 cm -1.5 cm

-3.7 cm -2 cm

There was a significant difference in pain reduction in the experimental group compared to control with a P = 0.000.

Author

Eligibily criteria

Random allocation

Concealed allocation

Baseline comparability

Blind subjects

Blind therapists

Blind assessors

Adequate follow-up 85%

Intention-to-treat analysis

Between-group comparisons

Point estimates and variability?

Score

Table 2. Results quality of the RCTs as PEDro Scale

Stevens M Horstmann T Roos EM Petersen W De Vos RJ Grävere K Tumilty S De Jonge S Tumilty S Rasmussen S Hutchison AM Stargioulas A Bjordal JM Rompe JD Rithesh Stasinopoulos D Netter C Zhang B

X X X X X X X X X X X X X X X X X X

X X X X X X X X X X X X X X X X X X

X X X X X X X X X X X X X X X X X X

X X O X X X X X X X X X X X O X O X

X X X X X X O X X X X X X O X X X X

O X O O O O X O X O O O O O O X X O

X O O O O O X O X X X X O X X O O X

O X O O X X O X X X X X X X X X X X

X X X X X X X X X X X X X X X X X X

X X X X X X X X X X X X X X X X X X

X X X X X X X X X X X X X X X X X X

8/10 9/10 6/10 7/10 8/10 8/10 8/10 8/10 9/10 8/10 8/10 8/10 7/10 8/10 8/10 9/10 9/10 9/10

Adapted from: PEDro scale. Available in: http://www.pedro.org.au/spanish/downloads/pedro-scale/

30

A. M. Díaz López, D. Gómez López and P. Guzman Carrasco

Regarding the level of improvement in the 5 trials where only exercises were held, significant efficacy was obtained in three trials [23, 25, 26] not reaching the degree of satisfaction expected from literature in one [24] although improvement was observed, the last trial [22] revealed no deterioration when performs normal activity versus resting. When combining with exercise and shock waves [12, 13] and US, Cyriax treatment, laser [18], and stretching [21] better results are obtained especially in functionality. It was less effective when comparing to US [20] regarding time of enhanced functionality and acupuncture [27] significant difference was found in the resulting pain relief more effective than exercise (ultrasound represent 6% of the techniques used). The following techniques most used were the use of shock waves, splints/orthopedic braces and laser 12.12% alone or combined each. Regarding the exclusive use of shock waves good results were obtained in 2 trials [14, 15] being the first one the best efficiencient in insertional tendinopathy. In the use of splints / orthoses when used in combination with exercises [8-11] they were not more effective than performing the exercises only. In the case of the application of laser, when applied to exclusively [17] was effective and when combined with exercises in two trials [16, 19] no difference in results was found with its use while another [18] use in combination with exercise accelerated the healing process. The techniques used only in one study (3.03% each) were: iontophoresis [29] using the dexamethasone can be effective in the treatment of acute Achilles tendinitis possibly due to decreased inflammation. With moderate results the Vibration therapy [30] shows an improvement of pain especially when insertional tendinopathy and no obvious improvement with the use of pulsed light [28] at vascular level or tendon regeneration as well as the ultrasound studies.

DISCUSSION As shown in this work there are multiple treatment options with physical therapy for conservative treatment of Achilles tendinopathy regarding the prospective studies (3), case-control (2) and randomized clinical trials (18) analyzed. The options are eccentric exercises (different program), shock waves, US, pulsed light, laser, vibration platform, iontophoresis and splints / orthotics. Due to this diversity and heterogeneity of the discussed techniques it has not been possible to make a quantitative analysis since there was no uniformity in the subjects selection, or methodology, different treatments and

Effectiveness of Different Physical Therapies …

31

even though when the technique was the same it was not applied in the same way. Among the physical therapies studied few showed a real and significant improvement of this condition so the generalization of eccentric exercise should be generalized as the only therapy that actually ameliorates short, medium and long-term Achilles tendinopathy improving the structure, pain, return to normal activity and sport and even being this therapy the one with the best satisfaction among the subjects [8, 10, 13, 16, 22, 23, 25]. Eccentric training programs have brought the most important change in the treatment of chronic forms of Achilles tendinopathy, but there is not enough data to say that the combination of other passive physical therapies with these programs improves the outcomes of isolated exercises [19]. When the application of eccentric exercises both non insertional tendinitis and insertion was studied in this review, these exercises are effective in both ways [9, 14, 23, 30]. Like other systematic reviews eccentric exercises show a real improvement of the affected tendon due to an improvement in the remodeling to facilitate venous flow by removing wastes [43]. The effectiveness of eccentric exercises has been compared and studied in different programs [23-25, 28] as well as eccentric exercises with other physical therapies other than exercises [12, 13, 16, 18-21, 27, 29, 30] and even exercises and resting with splints/braces [8-11] or without them [22]. Various types of eccentric exercises programs have been studied in this review, since treatment therapies developed by the authors of studies to standardized protocols eccentric exercises of the Achilles tendon as Alfredson and Stanish own protocol. According to Stanisopoulus it is the first which has a greater effectiveness in the treatment of tendinitis to reduce pain and to improve the functionality versus the Stanish protocol (values at 12 weeks with p < 0.05 paired t-test) [25]. It seems that the formalization of these exercises must be directed towards the patient's tolerance and since the beginning of the pathology [22-25, 30] taking into account the physical and professional subjects for its gradual integration into the sport and physical activity as pain and strength improve [8, 26]. The start of the eccentric activity from the beginning is in line with studies that have used the rest of the tendon both passively (use of splint) or active, as these have not significantly improved pain when they have been used in conjunction with eccentric exercises [9, 11]. However, Petersen in 2007, with a sample of 100 subjects found greater improvement in the group which they applied eccentric exercises and splint Airheel with higher scores on the scale for ankle and foot of the AOFAS, 12 points, with statistical significance relevance [10]. Studies show the effectiveness of these exercises then applying specific stretches of this tendon. There are multiple existing physical therapies but it seems that these are not the only way for monotherapy treatment as this form is ineffective, but

32

A. M. Díaz López, D. Gómez López and P. Guzman Carrasco

they should be used together with eccentric exercises treatment. Bjordal in 2006 in different RCTs tried to demonstrate the effectiveness of the low frequency laser. He found that there was a decrease especially in inflammation and pain threshold to pressure, but it is not a real improvement nowadays since measurements were made at 75, 90 and 105 minutes and the sample was only made of 7 subjects [17]. Not greater benefit was found in the application of low intensity laser in two RCTs conducted by the same author, Tumilty [16, 19]. In both RCTs comparing the application of shockwaves or not, more in depth the exercises application, there was an improvement in both the shockwaves group combined with long-term exercises although the improvement was not important [12, 13]. In the only prospective study that analyzed shock waves, Saxena 2011, these are both effective paratendinosis (75% improvement), tendinosis (78.26% and insertional tendinopathy (84.21%) were included. Intense pulsed light (IPL) is a kind of special lamp, which does not have the laser ability of being coherent and moving in the same direction and amplitude. The intense pulsed light source generates a high intensity polychromatic light with a spectrum of light between 515 nm and 1200 nm. It has been discovered the IPL effect on skin fibroblasts that stimulates them to produce more collagen. Hutchison, in an attempt to demonstrate the effectiveness of intense pulsed light in Achilles tendinopathy applied 3 sessions of treatment to 47 subjects. He found comparing the effectiveness VIS-A, the LEFS and the VAS [28] with placebo or scales or ultrasound objective evidence demonstrating changes at the vascular level or tendon regeneration. According to Horstmann using the vibration isolation platform decreases more eccentric pain and decreases in both work groups in the middle of the tendon (main difference in the vibration group -31.4; 95% CI -60.7, -2.0; main difference expectant group -50.2; 95% CI: -82.3, -18.1). But only improve musculotendinous level with eccentric exercises. The vibration treatment can be a complement to the eccentric and even alternative work insercional pain [30]. The US may be another alternative for improving Achilles tendinopathy. We reviewed two prospective studies that included it as a treatment. Chester in 2008 applied eccentric exercises with or without US performing better functionality and pain throughout the study in the group that applied both therapies [20]. Herrington applied Cyriax massages and US in a group and the same eccentric exercises finding more effectiveness in both groups but more on that also applied eccentric exercises. Iontophoresis applied with dexamethasone improves the inflammation especially at the beginning of the treatment [29] and acupuncture also decreases pain after 8 weeks of treatment and functionality for 24 weeks [27]. Shockwaves techniques, US vibrating laser platform, Cyriax, acupuncture and iontophoresis improved

Effectiveness of Different Physical Therapies …

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results of eccentric [12, 13, 15, 20, 21, 27, 29, 30] exercises. So the application of transverse Cyriax massages, shockwaves and US especially in subacute stage should be recommended. As to whether the laser is effective it can only base their recommendation to a prospective study but this does not give us adequate evidence for its recommendation. When laser therapy has been studied in clinical trials with group controls there has been a lack of effectiveness.

CONCLUSION Tendinopathies and particularly the Achilles tendinopathy is a condition in which it is still long way to go and investigate. It is known the part of the pathophysiology that produces this type of tendinopathy but there are still many of these mechanisms that are not known. Disorganization of the matrix, collagen, presence of pain-modulating substances or neuropeptides (substance P, glutamate, catecholamines, acetylcholine), neovascularization or structural alteration tenocytes level are the most significant findings that can be observed in this pathology. It seems that most authors agree that it is caused by overloading of the tendon that stars a degenerative process associated with histopathological changes. Traditionally conservative treatment of Achilles tendinopathy has placed special emphasis on measures aimed to control inflammation, but this approach is inappropriate given the absence of chemical inflammatory phenomena in chronic cases [44]. Bearing in mind that between 24 to 45.5% end up resorting to surgical option, even though this trend tends to dicrease and the conservative treatment has increasingly shown its effectiveness [45]. There are limitations to this review due to the the heterogeneity of the information found on the disparity of techniques applied, differences in the parameters in their application, duration of treatment and even subjects. There is no sufficient standardization in choosing the instruments for measuring the variables studied. There is also no standardization of instruments used to measure results using a variety of scales making it difficult to make a comparison between treatments. Studies with a small sample size can influence the results causing biased of treatment effects with the risk in the external validation. This presented review shows a variety of physical treatment alternatives that can be seen in the Achilles tendinitis. The only treatments that seem effective in isolation and that their effectiveness continues at the long term are

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eccentric exercises. These exercises can be made using standard protocols, or also proven progression levels as tolerated by patient, and followed by stretching. The rest does not seem justified in acute tendon pathology and the use of other therapies can increase the improvement with eccentric exercises especially at the level of inflammation and acute pain. These therapies are effective; shock waves, vibration platform, Cyriax, US, iontophoresis and acupuncture. Despite these results, it should increase effectiveness studies of these physical therapies in which are studied in isolation outside eccentric exercises. It should also study the effectiveness of physical therapy in insertional Achilles pathology. Nor yet we have enough data to stated that the combination of other passive additional therapies and progressive eccentric exercises programs improves the outcomes of isolated eccentric exercises.

ACKNOWLEDGMENT Our thanks to Ms. Patricia Torres Peso for their collaborations in the translation and proofreading.

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[17] Bjordal JM, Lopes‐Martins RA, Iversen VV. A randomised, placebo controlled trial of low level laser therapy for activated Achilles tendinitis with microdialysis measurement of peritendinous prostaglandin E2 concentrations. Br J Sports Med. 2006 Jan;40(1):76‐80. [18] Stergioulas A, Stergioula M, Aarskog R, Lopes‐Martins RA, Bjordal JM. Effects of low‐level laser therapy and eccentric exercises in the treatment of recreational athletes with chronic achilles tendinopathy. Am J Sports Med. 2008 May;36(5):881‐7. [19] Tumilty S, Munn J, Abbott JH, McDonough S, Hurley DA, Baxter GD. Laser therapy in the treatment of achilles tendinopathy: a pilot study. Photomed Laser Surg. 2008 Feb;26(1):25‐30. [20] Chester R, Costa ML, Shepstone L, Cooper A, Donell ST. Eccentric calf muscle training compared with therapeutic ultrasound for chronic Achilles tendon pain—a pilot study. Man Ther. 2008; 13(6):484‐91. [21] Herrington L, McCulloch R. The role of eccentric training in the management of Achilles tendinopathy: A pilot study. Phys Ther in Sport. 2007; 8(3):191-96. [22] Grävare K, Thomeé R, Eriksson BI, Karlsson J. Continued sports activity, using a pain-monitoring model, during rehabilitation in patients with achilles tendinopathy: A randomized controlled study. Am. J. Sports Med. 2007 Jan; 35(6): 897-906, originally published online Feb 16, 2007. [23] Verral G, Schofield S, Brustad T. Cronical Achilles tendinopathy treated with eccentric stretching program. J Foot Ankle Inter.2001 Sept;32 (9): 843-48. [24] Ram R, Meeuwisse W, Patel C, Wiseman DA, Wiley JP. The limited effectiveness of a home-based eccentric training for treatment of Achilles tendinopathy. Clin Invest Med. 2013; 36 (4): 197-206. [25] Stasinopoulos D, Manias P. Comparing two eccentric exercise programmes for the management of Achilles tendinopathy. A pilot trial. J Bodywork Move Therapies.ens. 2013 Jan; 17:309-15. [26] Steven M Tam CW. Effectiveness of the Alfredson protocol compared with a lower repetition-volume protocol for midportion Achilles tendinopathy: A randomized controlled trial. J Orth Sports Phys Ther. 2014 ; 44(2):59-67. [27] Zhang BM, Zhong LW, Xu SW, Jiang HR, Shen J. Acupuncture for chronic Achilles tendnopathy: a randomized controlled study. Chin J Integr Med. 2013;19(12):900-04.

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[28] Hutchison AM, Pallister I,Evans RM, Bodger O, Topliss CJ, Williams P, Beard J. Intense pulsed light treatment of chronic midbody Achilles tendinopathy. Bone Joint J 2013 March;95-B(3):??–?? [29] Neeter C, Thomee R, Silbernagel KG, Thomee P, Karlsson J. Iontophoresis with or without dexamethazone in the treatment of acute Achilles tendon pain. Scand J Med Sci Sports. 2003;13(6):376-82. [30] Horstmann T, Holger M, Fröhlich V, Mündermann A, Grau S. WholeBody vibration versus eccentric training or a wait-and-see approach for chronic Achilles tendinopathy. J Ortho Sport Phys Ther. 2013 Nov; 43(11):794-803. [31] Moseley AM, Herbert RD, Sherrington C, Maher CG. Evidence for physiotherapy practice: a survey of the Physiotherapy Evidence Database (PEDro). Aust J Physiother. 2002;48: 43-9. [32] Magnussen RA, Dunn WA, Thomson AB. Nonoperative Treatment of Midportion Achilles Tendinopathy: A Systematic Review. Clin J Sport Med 2009;19:54–64. [33] Tumilty S, Munn J, McDonough S, Hurley DA, Basford JR, Baxter GD. Low Level Laser Treatment of Tendinopathy: A Systematic Review with Meta-analysis. Photomed Laser Surg. 2009;00(00):1-14. [34] Sussmilch-Leitch, SP Collins NJ, Bialocerkowski NE, Warden SJ Crossley KM. Physical therapies for Achilles tendinopathy: systematic review and meta-analysis. J Foot Ankle Res. 2012;5:1-15. [35] Balado E, Rodríguez G. Tratamiento fisioterápico en la tendinopatía crónica de Aquiles. Revisión bibliográfica. Fisioterapia. 2012; 34(6):257-266 [36] Malliaras P, Barton CJ, Reeves ND, Langberg H. Achilles and Patellar Tendinopathy Loading Programmes A Systematic Review; Comparing Clinical Outcomes and Identifying Potential Mechanisms for Effectiveness. Sports Med. 2013;43(4):267-86. [37] Al-Abbad H, Simon JV. The Effectiveness of Extracorporeal Shock Wave Therapy on Chronic Achilles Tendinopathy: A Systematic Review. Foot Ankle Inter.2013;34(1): 33–41. [38] Scott A, Huisman E, Khan K. Conservative treatment of chronic Achilles tendinopathy. CMAJ. 2011; 183(10):1159-65. [39] McLauchlan G, Handoll HHG. Interventions for treating acute and chronic Achilles tendinitis. Cochrane Database of Systematic Reviews 2001, Issue 2. Art. No.: CD000232. DOI: 10.1002/14651858.CD000232. [40] Carcia CR, Martin RL, Houck J, Wukich DK. Achilles Pain, Stiffness, and Muscle Power Deficits: Achilles Tendinitis Clinical Practice

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A. M. Díaz López, D. Gómez López and P. Guzman Carrasco Guidelines Linked to the International Classification of Functioning, Disability, and Health from the Orthopaedic Section of the American Physical Therapy Association. J Orthop Sports Phys Ther. 2010;40(9): A1-A26. Robinson JM, Cook J, Purdam C, Visentini P, Ross J, Maffulli N, et al. The VISA-A questionnaire: a valid and reliable index of the clinical severity of Achilles tendinopathy. Br J Sports Med 2001;35:335–41. Stanish WD, Rubinovich RM, Curwin S. Eccentric exercise in chronic tendinitis. Clin Orthop Rel Res. 1986; 208: 65-8. Alfredson H, Pietilä T, Jonsson P, Lorentzon R. Heavy-load eccentric calf muscle training for the treatment of chronic Achilles tendinosis. Am J Sports Med. 1998; 26:360-6. Rees JD, Wilson AM, Wolman RL. Current concepts in the management of tendon disorders. Rheumatology. 2006; 45: 508-21. Maffulli N, Sharma P, luscombe K. Achilles tendinopathy: Aetiology and management. J of the Royal Societty of Med. 2004; 97(10):472-76.

ANNEX 1 Methodological quality criteria used to assess intervention studies and prospective A. Representativeness of the final study sample 1. At least one occurrence of the following elements in the study: full target population, randomly selected sample or indicated to represent the population. 2. At least one of the following: description of the target population, diagnostic method used, time of evolution of the disease. 3. Dropout rate or failure rate. B. Quality of data 1. If it specifies the assessment scales used. 2. Comparative assessments were made before and after interventions or between groups. 3. If it specifies statistics outcomes. 4. Consent report signed by the patient or approval by an ethics committee to develop the study

In: Achilles Tendon and Ankle Injuries ISBN: 978-1-63483-484-1 Editor: Arthur Adams © 2015 Nova Science Publishers, Inc.

Chapter 2

EVALUATION OF ACHILLES TENDON LENGTH CHANGES IN HUMANS Atsuki Fukutani1,2,3, Akinori Nagano4 and Tadao Isaka4 1

Research Organization of Science and Technology, Ritsumeikan University, Shiga, Japan 2 Japan Society for the Promotion of Science, Research Fellowship for Young Scientists, Tokyo, Japan 3 The Faculty of Kinesiology, Human Performance Laboratory, University of Calgary, Alberta, Canada 4 Faculty of Sport and Health Science, Ritsumeikan University, Shiga, Japan

ABSTRACT The tendon is considered to have a significant role in human movement because it can store and release elastic energy, which enhances the force-generating capability of the muscle-tendon complex. Therefore, sports scientists and physical therapists are interested in the behavior of tendons, such as the Achilles tendon, during movements such as running and jumping. Recently, imaging modalities, including ultrasonography and magnetic resonance imaging, have improved, enabling measurement of tendon length changes during muscle contractions in humans under certain physiologic conditions. With this situation in mind, first, the possible role of tendon length changes in force-generating capability of

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Atsuki Fukutani, Akinori Nagano and Tadao Isaka the muscle-tendon complex is introduced. Results obtained from animal studies also are included in this part. Second, methods to evaluate tendon length changes in humans, especially of the Achilles tendon, including ultrasonography, magnetic resonance imaging, and estimation equation methods, are described. Currently, these methods have been widely applied in the relevant scientific community. Finally, interpretation of the results obtained by using the above mentioned methods is provided. Because each method has some limitations, care should be taken when interpreting these results. Knowledge of these points would lead to better understanding of the behavior of tendons, and consequently, better understanding of the force-generating capability of the muscle-tendon complex.

INTRODUCTION Human movement is generated by rotation of bones. Rotation of bones is induced by force generated by muscles. Such muscle force is transmitted to bones via tendons. Thus, not only muscles but also tendons are related to performance of human movement. For transmitting muscle force efficiently to bones, tendons should be stiff. However, tendons have another role in human movement. Because tendons have some compliance, tendons can be elongated by muscle force. Consequently, tendons can store and release elastic energy during dynamic movement (Alexander and Bennet-Clark 1977, Morgan et al. 1978, Biewener et al. 1998). According to a study by Ker (1981), magnitude of dissipation of elastic energy stored in a tendon examined by oscillation test was only 7%. This result indicates that approximately 93% of negative work done during the eccentric contraction phase is converted to positive work during the subsequent concentric contraction phase (Alexander 2002). Thus, tendons have a significant role in performance of human movement. As such, the behavior of tendons (i.e., tendon length changes) during human movement is an intriguing topic, especially in the fields such as sports science and physical therapy for better understanding of mechanism of human movements. In this chapter, we introduce (1) the role of tendon length changes in forcegenerating capability of the muscle-tendon complex, (2) how to measure

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tendon length changes in humans, and (3) what we have to consider when interpreting tendon length changes calculated by using current methods.

Figure 1. Muscle fiber length, muscle force, and activity for the lateral gastrocnemius of a turkey running at 3m/s on level ground (A) and up a 12° incline (B). Muscle fiber length was measured by sonomicrometry implanted into the muscle. During stance phase, muscle fiber length contracted isometrically (From Roberts et al. 1997 with permission).

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ROLE OF TENDON LENGTH CHANGES IN FORCE-GENERATING CAPABILITY Roberts et al. (1997) found that during running in turkey, muscle fascicle length of the lateral gastrocnemius behaved isometrically, whereas joint angle clearly changed (Figure 1). This result shows that the tendon is elongated instead of the muscle during movement, as consequently, tendons can store and release elastic energy (Alexander and Bennet-Clark 1977, Morgan et al. 1978, Biewener et al. 1998). This elastic energy is considered to have a significant role in the human movements, especially in stretch-shortening cycle, which is comprised of an eccentric contraction and the subsequent concentric contraction (Cavagna et al. 1968, Komi 2000). Specifically, elastic energy is stored in the tendon during the eccentric (lengthening) contraction phase, and the stored elastic energy is released during the subsequent concentric (shortening) contraction phase. Due to this spring-like behavior of the tendon, work done by the muscle-tendon complex during the concentric contraction phase is larger in a stretch-shortening cycle than in a pure concentric contraction condition (i.e., without prior eccentric contraction). In addition to the function of storing and releasing elastic energy, tendon length changes can modulate force-generating capability of muscle because tendon length changes directly affect muscle length changes. Specifically, the muscle-tendon complex is elongated during the eccentric contraction phase. In this phase, if the tendon is elongated instead of the muscle, muscle length does not change or magnitude of muscle elongation decreases (Figure 2). Because length and shortening/lengthening velocities of muscle affect force-generating capability according to the force-length relationship (Edman 1966, Gordon et al. 1966, ter Keurs et al. 1978) and the force-velocity relationship (Gasser and Hill 1924, Fenn 1924, Hill 1938), tendon length changes directly affect forcegenerating capability of muscle. This phenomenon is often called muscletendon interaction (Fukunaga et al. 2002, Ishikawa et al. 2005b, Sano et al. 2013). Because of this muscle-tendon interaction, muscle (muscle fascicle) can behave isometrically while joint angle changes, in such movement patterns as walking (Fukunaga et al. 2001) and countermovement exercise (Kawakami et al. 2002). Compared with concentric contraction, isometric contraction can produce larger force because of the force-velocity relationship (Gasser and Hill 1924, Fenn 1924, Hill 1938). Thus, muscle-tendon interaction can augment muscle force.

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Figure 2. Schematic illustration of the length changes of muscle-tendon complex. When tendon length does not change, muscle length change is identical with muscletendon complex length change. On the other hand, if tendon elongates during elongation of the muscle-tendon complex, the extent of muscle elongation is attenuated.

Tendon elongation is also beneficial from the viewpoint of preventing muscle damage induced by eccentric contraction. It is widely known that compared with isometric and concentric contractions, eccentric contraction (muscle lengthening) induces muscle damage (Clarkson and Hubal 2002, Peake et al. 2005, Proske and Allen 2005). During eccentric contraction, muscle is elongated actively, which can lead to the muscle damage. However, if the tendon is elongated instead of the muscle at a given muscle-tendon complex elongation, magnitude of muscle elongation decreases, which can attenuate muscle damage. In this regard, Hoffman et al. (2014) reported that tendon contribution to overall muscle-tendon complex elongation of the medial gastrocnemius during backward downhill walking was approximately 91%. This finding indicates that muscle fascicle elongation was attenuated by tendon elongation, which is beneficial for preventing muscle damage. In addition, Peñailillo et al. (2014) examined muscle damage during eccentric cycling exercise, and reported that extent of muscle soreness was associated with extent of muscle fascicle elongation, suggesting that smaller muscle fascicle elongation (i.e., larger tendon elongation) would reduce muscle soreness. Considering these results, tendon elongation can function as a ―shock absorber‖ for preventing muscle damage.

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Figure 3. Example of an ultrasonographic image of the anterior leg at a point 50% distal to the length of tibial bone. The intersection between muscle fascicle and deep aponeurosis (η) was traced (From Fukashiro et al. 1995 with permission).

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TECHNIQUES TO MEASURE TENDON LENGTH CHANGES IN HUMANS Ultrasonography Because tendons lie under the skin, tendon length changes cannot be confirmed outside of the skin. Consequently, it is difficult to measure tendon length changes in humans under certain physiologic conditions. However, due to advancements in the technology of ultrasonography, which can visualize the inside of the human body, we can easily evaluate tendon length changes under physiologic conditions. In 1995, Fukashiro et al. (1995) examined tendon length changes during isometric contraction in vivo. In their study, the intersection between muscle fascicle and aponeurosis (i.e., the internal tendon) was visualized by using ultrasonography (Figure 3). They considered that displacement of this intersection was equivalent to the magnitude of tendon elongation of the tibialis anterior. Based on this displacement and force calculated by joint torque divided by moment arm, the force-length relationship of the tendon was evaluated. After this article was published, this measurement method was accepted, and has been widely used in many studies (Kubo et al. 2002, Maganaris and Paul 2002, Muraoka et al. 2004). In these studies, tendon characteristics were evaluated mainly by stiffness. The stiffness index is calculated by using the following equation: stiffness (N/m) = force (N) / tendon elongation (m) Generally, it is difficult to measure force applied to the tendon directly in vivo. Therefore, force is calculated by using the following equation: force (N) = joint torque (Nm) / moment arm (m) Joint torque is obtained directly by using a dynamometer, and moment arm is obtained by using the tendon travel method (Spoor and van Leeuwen 1992, Ito et al. 2000, Fath et al. 2010) or the center of rotation method by using magnetic resonance imaging (MRI) (Rugg et al. 1990, Akagi et al. 2012, Sugisaki et al. 2014). In addition to these methods, constant values obtained in previous studies have been adopted in some cases in which measurement of moment arm is difficult (In this case, we cannot consider inter-individual differences of the moment arm). Using the above equations, tendon stiffness is calculated from the force-length relationship of the tendon (Figure 4) (Wang

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2006). The slope of the force-length relationship demonstrates tendon stiffness. Because the first phase of the slope (―toe region‖ in Figure 4) shows smaller stiffness values compared with the latter phase (―linear region‖ in Figure 4), due to the influence of eliminating the ―crimp‖ shape of tendon (i.e., eliminating the zigzag pattern of collagen fiber), the mechanical property of the tendon (stiffness) is generally calculated within 50% to 100% of the maximal voluntary contraction region (Kubo et al. 1999, 2012). Calculated tendon stiffness is affected by morphologic properties, including tendon length and tendon cross-sectional area. Specifically, magnitude of elongation is larger in longer tendons than in shorter tendons, even if the material property is identical. In addition, tendons with a small cross-sectional area are easy to be elongated compared with tendons with a large cross-sectional area, at a given muscle force. Taking these factors into consideration, the stiffness index is not necessarily sufficient to evaluate tendon characteristics. Therefore, an index of Young‘s modulus is also calculated to evaluate tendon ―quality‖ (Kubo et al. 2001, Magnusson et al. 2003, Waugh et al. 2012). Young‘s modulus is calculated by using the following equation:

Figure 4. Length (strain) and force (stress) relationship of the tendon. Stiffness (Young‘s modulus) is calculated at the ―linear region‖ (From Wang 2006 with permission).

Young‘s modulus (Pa) = stress (Pa) / strain

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Stress is calculated as force (N) normalized by cross-sectional area (m2). The unit of stress is pascal (or N/m2). On the other hand, strain is calculated as amount of tendon elongation (m) normalized by initial tendon length (m). Thus, the unit of strain is dimensionless. Considering these facts, for calculating Young‘s modulus, data on muscle force, tendon cross-sectional area, amount of tendon elongation, and initial tendon length are required. As described above, muscle force is calculated by using joint torque and moment arm. Tendon cross-sectional area is obtained by using ultrasonography or MRI. Amount of tendon elongation is obtained by using ultrasonography measurement around the proximal muscle-tendon junction (or the intersection between muscle fascicle and aponeurosis). Initial tendon length is obtained by using a flexible ruler or MRI. Generally, Young‘s modulus is used to evaluate the material property (quality) of the tendon, while the stiffness is used to evaluate the mechanical property (not only quality but also morphologic properties, such as length and cross-sectional area, are taken into consideration) of the tendon. Thus, stiffness is more strongly related to the actual performance of human movements

Magnetic Resonance Imaging Ultrasonography is widely used to evaluate tendon characteristics because measurement can be performed noninvasively with sufficient time resolution (30 Hz or higher). However, field of view of ultrasonographic measurement is limited, i.e., an ultrasonographic image is obtained with a limited range (6-10 cm) in two dimensions projected to a given plane that is not necessarily the actual plane of tendon elongation. To overcome these problems, MRI has been used instead of ultrasonography (Shin et al. 2008, Kinugasa et al. 2010, Iwanuma et al. 2011b). Because MRI has a larger field of view compared with ultrasonography, MRI can visualize the whole tendon. In addition, it is much easier to obtain three-dimensional (3D) information using MRI compared with ultrasonography. Taken together, MRI seems to be a better method for calculating tendon elongation compared with ultrasonography. As such, recent studies have attempted to evaluate tendon characteristics by using MRI. For example, Iwanuma et al. (2011b) used MRI to measure Achilles tendon length changes during submaximal isometric contraction, and reported that length changes of the aponeurosis in the longitudinal direction were 1.1% and 1.6% for 30% and 60% of maximal voluntary contraction, respectively. In addition to longitudinal strain, the researchers also measured transverse strain (i.e.,

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perpendicular to the longitudinal direction), and reported that transverse strain seemed to be larger than longitudinal strain (5-10%) (Figure 5). In the case of ultrasonography measurement, obtaining data on transverse strain is difficult. Furthermore, MRI can visualize the whole Achilles tendon unlike ultrasonography measurement. Thus, the value obtained by using MRI seems to be more reasonable than that obtained by using ultrasonography. Taken together, MRI would be currently the best method to evaluate tendon characteristics.

Figure 5. Longitudinal (upper) and transverse (lower) length changes (i.e., strain) of the Achilles tendon. ATapo means aponeurosis of the Achilles tendon. ATten means free tendon of the Achilles tendon (From Iwanuma et al. 2011 with permission).

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Estimation Equation As described above, MRI is currently the best method to obtain accurate values of tendon characteristics. However, because time resolution of MRI is very low (at least several seconds is required), MRI cannot be applied to dynamic movements, such as jumping or running, which complete within one second. In light of this fact, another method for evaluating tendon characteristics has been developed (Fukunaga et al. 2001, Ishikawa et al. 2007, Lichtwark et al. 2007). In this method, tendon length changes are evaluated by using an estimation equation and an ultrasonographic measurement of muscle fascicle length (Figure 6). First, muscle-tendon complex length change is estimated by using joint angle changes with an assumption that both ends of the muscle-tendon complex (i.e., origin and insertion) change in accordance with joint angle changes. This estimation equation was published by Grieve et al. (1978) and Hawkins and Hull et al. (1990). Joint angles are measured by using a goniometer or a motion analysis system. Second, muscle length (i.e., muscle fascicle length) is obtained by using ultrasonography. Unlike aforementioned ultrasonographic measurement, this ultrasonographic measurement is for obtaining the muscle fascicle length, not the location of intersection between tendon and muscle fascicle (or aponeurosis and muscle fascicle). Pennation angle is also considered (i.e., muscle fascicle length obtained by using ultrasonography is divided by the cosine of pennation angle). Third, calculated muscle fascicle length change is subtracted from calculated muscle-tendon complex length change. As a result, tendon length changes can be calculated. This method has been widely used in many studies. For example, Fukunaga et al. (2001) examined Achilles tendon length changes during walking by using above estimation equation, and found that the muscle contracted near-isometrically in the stance phase, while the Achilles tendon elongated and shortened. From these results, they suggested that elastic energy stored in the Achilles tendon and muscle-tendon interaction contribute to improving the performance of human movement. This concept has been reconfirmed in other movements as well. For example, Kawakami et al. (2002) examined Achilles tendon length changes during countermovement of ankle joint, and confirmed the same phenomenon as Fukunaga et al. (2001), i.e., the muscle fascicle behaved near-isometrically while muscle-tendon complex length changed substantially.

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WHAT WE HAVE TO CONSIDER WHEN INTERPRETING TENDON LENGTH CHANGES CALCULATED BY USING CURRENT METHODS During Isometric Contraction As described above, Achilles tendon length changes during isometric contraction have been obtained by evaluating displacement of the muscletendon junction (or the intersection between muscle fascicle and aponeurosis) (Fukashiro et al. 1995, Ito et al. 1998). In other words, whole Achilles tendon length was not visualized in these studies (Figure 7). They presumed that the ankle joint was perfectly fixed (i.e., the distal end of the Achilles tendon did not move at all), so that displacement of the proximal end of the tendon (or the intersection between muscle fascicle and aponeurosis) represents Achilles tendon length change. However, it is difficult to completely prevent any joint angular rotation during muscle contraction, even if the joint is tightly fixed with a non-elastic strap (Magnusson et al. 2001, Arampatzis et al. 2005). In other words, not only the proximal end but also the distal end of the Achilles tendon moves during isometric contraction. This ankle joint angle change leads to overestimation of Achilles tendon elongation. Thus, Achilles tendon length changes should be corrected by subtracting the amount of Achilles tendon length change induced by ―joint angle rotation‖ during passive ankle joint rotation from the amount of Achilles tendon length change induced by both ―muscle force‖ and ―joint angle rotation‖ during isometric contraction. Furthermore, Iwanuma et al. (2011a) reported that the calcaneus where the Achilles tendon attaches can be moved (rotated) by muscle contraction, indicating that the distal end of the Achilles tendon changes during isometric contraction. Thus, we have to consider that Achilles tendon length changes estimated from displacement of the proximal end of the tendon (or the intersection between muscle fascicle and aponeurosis) do not necessarily represent Achilles tendon elongation. Moreover, the above ultrasonography method assumes that the Achilles tendon behaves as a straight line. Because ultrasonography tracks only displacement of the proximal end of the Achilles tendon, this method neglects the shape of the Achilles tendon. However, because the shape of the Achilles tendon changes (Fukutani et al. 2014), the above assumption should be reconsidered. Specifically, even if actual Achilles tendon length does not

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Figure 6. Achilles tendon length change calculated by the estimation equation. 1 shows muscle-tendon complex length change. 2 shows muscle fascicle length change (corrected by cosine alpha). 3a shows (distal) free tendon length change. 3b shows aponeurosis (and proximal free tendon). Achilles tendon length change is obtained by subtracting muscle fascicle length change from muscle-tendon complex length change. Note that calculated tendon length change includes not only length change in free Achilles tendon but also that in aponeurosis.

Figure 7. Schematic illustration of the measurement of tendon length. Visualizing area by ultrasonography is limited only around the proximal end of the Achilles tendon.

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change, the straight distance between distal and proximal ends of the tendon becomes shorter if the shape of the tendon changes from straight to curved (Figure 8). As mentioned in the above paragraph, ankle joint angle changes to some extent even during isometric contraction from neutral (or dorsiflexion) to plantar flexion. As a result, the curved shape of the Achilles tendon is emphasized during isometric contraction compared with during relaxation. This leads to overestimation of Achilles tendon length changes. Thus, not only the proximal end of the tendon but also the whole shape of the tendon should be visualized in order to accurately evaluate characteristics of the Achilles tendon. We have to mention the influence of orientation of the ultrasonographic probe on measurement accuracy. Information obtained from ultrasonographic measurement is two-dimensional (2D) data projected onto a given plane that is not necessarily identical to the actual plane of tendon excursion. Thus, magnitude of displacement measured on a plane projected onto a given plane is not necessarily identical to actual magnitude of displacement in a 3D space.

Figure 8. Schematic illustration of the shapes of the Achilles tendon. At the dorsiflexion position (left figure), the Achilles tendon length is almost straight, whereas Achilles tendon shows curved shape at the plantar flexion position (right figure). When the Achilles tendon seems as straight line, its length is underestimated at the plantar flexion position although its length is almost same at the dorsiflexion position. This underestimation only in plantar flexion position leads to the overestimation of the Achilles tendon length change (muscle-tendon complex length change) when ankle joint angle moves from dorsiflexion position to plantar flexion position.

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Figure 9. Schematic illustration of the change in triceps surae shape according to muscle contractions. If ultrasonographic probe is attached near the muscle-tendon junction (in the black circle), the orientation of the ultarsonographic probe (imaging plane) may be changed according to the muscle contraction.

A similar problem was pointed out by Klimstra et al. (2007). In their study, orientation of the ultrasonographic probe affected measurement of fascicle length and pennation angle. With regard to the influence of orientation of the ultrasonographic probe, we also have to consider deformation of the triceps surae induced by muscle contraction. During stiffness measurement of the Achilles tendon, the shape of the triceps surae will change in accordance with muscle contraction (Figure 9). This deformation may change the orientation of the ultrasonographic probe attached on the triceps surae. As a result, location of the proximal end of the Achilles tendon seems to move, though the actual location does not change at all (Figure 10). One of the ways to overcome this problem is to obtain a local coordinate system for the ultrasonographic probe and a global coordinate system for correcting the influence of changes in orientation of the ultrasonographic probe. This correction may work in some cases, unless the actual muscle-tendon junction leaves the field of view of the ultrasonographic image. However, it is quite difficult to know how much the ultrasonographic probe is misaligned relative to the actual plane of tendon excursion because we cannot confirm the actual plane of tendon excursion outside of the skin, even though obtaining a local coordinate system for the ultrasonographic probe is relatively easy. Taken together, the current tracking

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method for displacement of the actual muscle-tendon junction by using 2D ultrasonographic images includes some problems. As such, MRI seems to be potentially useful because it can visualize the whole Achilles tendon in 3D. However, because the time resolution of MRI is very low (at least several seconds), MRI is generally used only in constant joint angle conditions, such as during relaxation or isometric contraction (Iwanuma et al. 2011a, 2011b). In addition, another problem we have to consider is that because the Achilles tendon does not have a simple straight configuration like straight pole, the definition of Achilles tendon ―length‖ is ambiguous. Specifically, how do we measure Achilles tendon length? Straight distance from proximal end to distal end? Or curved distance along the edge of the tendon? Because it is obvious that Achilles tendon length differs depending on the measurement method, this point should be considered when evaluating calculated Achilles tendon length changes using MRI.

During Dynamic Contraction Because MRI cannot be applied during dynamic movements, such as jumping and running, due to limited time resolution, the estimation equation has been applied for evaluating Achilles tendon length changes (Fukunaga et al. 2001, Ishikawa et al. 2007, Lichtwark et al. 2007). As described above, this method includes some assumptions. In brief, Achilles tendon length changes are estimated by subtracting change in muscle length (i.e., muscle fascicle length) from change in muscle-tendon complex length of the triceps surae, which is estimated by using knee and ankle joint angle changes. However, this concept involves the following three problems, as pointed out partly by Fukutani et al. (2014). First, this estimation equation is accurate only when changes in knee and ankle joint angles accurately represent changes in muscle-tendon complex length. However, as described above, Iwanuma et al. (2011a) reported that a change in ankle joint angle does not necessarily represent a change in muscletendon complex length because the calcaneus, which is the insertion of the Achilles tendon, undergoes rotation by muscle force, even without changing ankle joint angle. Thus, changes in muscle-tendon complex length estimated by using joint angle changes do not necessarily represent actual muscle-tendon complex length changes. As a result, Achilles tendon length changes are overestimated.

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Figure 10. Influence of change in orientation of the ultrasonographic probe. Although the location of muscle-tendon junction does not change, its location obtained by ultrasonographic image changes when orientation of ultrasonographic probe changes (the angle of upper figure is 0 degree, and that of lower figure is 30 degree).

Second, previous studies have calculated changes in muscle fascicle length from a single muscle (e.g., the medial gastrocnemius) (Fukunaga et al. 2001, Kurokawa et al. 2003, Hoffrén et al. 2012). However, the triceps surae is composed of not only the medial gastrocnemius but also the lateral gastrocnemius and the soleus. These muscles share the same tendon, the Achilles tendon. Considering the fact that extent of changes in muscle fascicle length may not necessarily be identical among these three muscles (Ishikawa et al. 2005a), changes in muscle fascicle length obtained from one muscle alone cannot accurately reflect changes in Achilles tendon length. In concrete, estimated Achilles tendon length changes may be different depending on the muscle tested.

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Figure 11. Experimental set up of Fukutani et al. (2014). Achilles tendon length in 3D curve was calculated as the sum of the 3D distances between adjacent markers. Achilles tendon length in 2D straight was calculated as the straight distance between the markers attached to both ends of the Achilles tendon projected onto the sagittal plane (X-Z). Achilles tendon length in 3D straight was calculated from the 3D coordinates of two makers attached to both ends of the Achilles tendon. Achilles tendon length in 2D curve was calculated as the sum of the distances among the 2D coordinates of all markers projected onto the sagittal plane (From Fukutani et al. 2014 with permission).

Third, the estimation equation assumes that the muscle-tendon complex behaves as a straight line. However, the muscle-tendon complex of the triceps surae has a curved shape (Stosic and Finni 2011, Fukutani et al. 2014), especially in the plantar flexion region. In the presence of curvature, muscletendon complex length calculated by using a straight-line model is inevitably underestimated compared with that calculated by using a curved-line model. Because the shape of the Achilles tendon is almost straight in the dorsiflexion region but curved in the plantar flexion region, Achilles tendon length obtained by using a straight-line model would be underestimated only in the

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plantarflexion region. Consequently, muscle-tendon complex length changes would be overestimated. This overestimation of muscle-tendon complex length changes leads to overestimation of Achilles tendon length changes (muscle-tendon complex length changes). The influence of neglecting the curved shape of the Achilles tendon on its changes in length was clearly illustrated in a previous study (Fukutani et al. 2014), which compared Achilles tendon length changes obtained by using four different surface marker methods (3D curved line model, 3D straight line model, 2D curved line model, and 2D straight line model) (Figures 11, 12). In their study, Achilles tendon length changes were obtained when the ankle joint was moved from 15° dorsiflexion to 30° plantarflexion. In the 2D and 3D straight line models, which ignored the curved shape of the tendon, calculated Achilles tendon length changes were larger than those obtained in the 2D and 3D curved line models, which considered the curved shape of the tendon. These results show that if the curved shape of the Achilles tendon is not considered, magnitude of Achilles tendon length changes is overestimated.

Figure 12. Achilles tendon length changes calculated by four different methods. Achilles tendon length change was overestimated in 3D straight and 2D straight (which ignored curved shape of the Achilles tendon) compared to the 3D curve (reference value) (From Fukutani et al. 2014 with permission).

In addition, we have to consider that Achilles tendon length changes calculated by using the estimation equation represent not only free Achilles tendon length changes (i.e., the distal side from the muscle-tendon junction, Figure 6. 3a) but also aponeurosis length changes (i.e., inside the muscle, which is the proximal side from the muscle-tendon junction, Figure 6, 3b).

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Consequently, the values obtained by using the estimation equation cannot evaluate the free Achilles tendon and the aponeurosis separately. Previous studies have reported that magnitude of elongation of the free Achilles tendon and the aponeurosis were different depending on the location tested (Kaya et al. 2003, Iwanuma et al. 2011b). In addition, Herzog (Nigg and Herzog 2007) reported that the aponeurosis was shortened even during muscle contraction (Figure 13), indicating that the aponeurosis does not behave like simple elastic material in series, such as the free Achilles tendon. Taking these findings into account, we have to evaluate characteristics of the free Achilles tendon and the aponeurosis separately. Hence, care must be taken when interpreting the physiologic meaning of Achilles tendon length changes obtained by using the estimation equation.

Figure 13. Experimental setup for the aponeurosis length measurement by sonomicrometry (A), and result (B) of aponeurosis length changes. Note that aponeurosis was shorten even the medial gastrocnemius (MG) force increased. This result clearly shows that aponeurosis does not behave simple elastic spring in series (From Nigg and Herzog with permission).

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CONCLUSION Because tendon length changes have a significant role in human movement, especially dynamic movement, their measurement is crucial to clarify the mechanism of human movement. Thus, understanding how to measure tendon length changes is of importance. Because the current methods have some limitations, however, reasonable interpretation of the results considering these limitations is required, and a better method for evaluating tendon length changes should be developed in the future.

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[45] Morgan, DL; Proske, U; Warren, D. Measurements of muscle stiffness and the mechanism of elastic storage of energy in hopping kangaroos. J Physiol. 1978. 282, 253-261. [46] Muraoka, T; Muramatsu, T; Fukunaga, T; Kanehisa, H. Geometric and elastic properties of in vivo human Achilles tendon in young adults. Cells Tissues Organs. 2004. 178(4), 197-203. [47] Peake, J; Nosaka, K; Suzuki, K. Characterization of inflammatory responses to eccentric exercise in humans. Exerc Immunol Rev. 2005. 11, 64-85. [48] Peñailillo, L; Blazevich, A; Nosaka, K. Muscle Fascicle Behavior during Eccentric Cycling and Its Relation to Muscle Soreness. Med Sci Sports Exerc. 2014 (In press) [49] Proske, U; Allen, TJ. Damage to skeletal muscle from eccentric exercise. Exerc Sport Sci Rev. 2005. 33(2), 98-104. [50] Roberts, TJ; Marsh, RL; Weyand, PG; Taylor, CR. Muscular force in running turkeys: the economy of minimizing work. Science. 1997. 275(5303), 1113-1115. [51] Rugg, SG; Gregor, RJ; Mandelbaum, BR; Chiu, L. In vivo moment arm calculations at the ankle using magnetic resonance imaging (MRI). J Biomech. 1990. 23(5), 495-501. [52] Sano, K; Ishikawa, M; Nobue, A; Danno, Y; Akiyama, M; Oda, T; Ito, A; Hoffrén, M; Nicol, C; Locatelli, E; Komi, PV. Muscle-tendon interaction and EMG profiles of world class endurance runners during hopping. Eur J Appl Physiol. 2013. 113(6), 1395-1403. doi: 10.1007/ s00421-012-2559-6. [53] Shin, D; Finni, T; Ahn, S; Hodgson, JA; Lee, HD; Edgerton, VR; Sinha S. In vivo estimation and repeatability of force-length relationship and stiffness of the human achilles tendon using phase contrast MRI. Magn Reson Imaging. 2008. 28(4), 1039-1045. doi: 10.1002/jmri.21533. [54] Spoor, CW; van Leeuwen, JL. Knee muscle moment arms from MRI and from tendon travel. J Biomech. 1992. 25(2), 201-206. [55] Stosic, J1; Finni, T. Gastrocnemius tendon length and strain are different when assessed using straight or curved tendon model. Eur J Appl Physiol. 2011. 111(12), 3151-3154. doi: 10.1007/s00421-011-1929-9. [56] Sugisaki, N; Wakahara, T; Murata, K; Miyamoto, N; Kawakami, Y; Kanehisa, H; Fukunaga, T. Influence of muscle hypertrophy on the moment arm of the triceps brachii muscle. J Appl Biomech. 2014. (In press)

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In: Achilles Tendon and Ankle Injuries ISBN: 978-1-63483-484-1 Editor: Arthur Adams © 2015 Nova Science Publishers, Inc.

Chapter 3

THE EVOLUTION OF THE ACHILLES TENDON B. Tucker1,* and W. S. Khan2 1

University College London Medical School, Gower Street, London, UK University College London Institute of Orthopaedics and Musculoskeletal Sciences, Royal National Orthopaedic Hospital, Stanmore, Middlesex, UK

2

ABSTRACT The Achilles tendon is a key structure separating humans from other primates, allowing the upright bipedal stance. There are many advantages to being a biped from hunting ability to energy expenditure. The Achilles tendon itself has the benefit of greatly enhancing endurance running. However, there are disadvantages to having an Achilles tendon such as its vulnerability to injury. This article outlines the advantages and disadvantages of the tendon and highlights some theories as to why humans may have evolved to have it.

Keywords: Achilles tendon, evolution, bipedal stance, injury

*

Corresponding author: Mr Wasim S Khan, Clinical Lecturer, University College London Institute of Orthopaedics and Musculoskeletal Science, Royal National Orthopaedic Hospital, Stanmore, Middlesex, London, HA7 4LP, UK, Telephone number: +44 (0) 7791 025554, Fax number: +44 (0) 20 8570 3864 E-mail address: [email protected].

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The Achilles tendon plays a major part in modern human bipedalism. The evolution of the Achilles tendon is not well known but there are many theories of the origin of bipedalsim. This article outlines the advantages and flaws of this form of locomotion in relation to the Achilles tendon. The Achilles tendon is the common tendon of the soleus and gastrocnemius. It attaches these muscles to the calcaneus bone of the heel. Its key role is therefore in elevation of the heel. The effect of the Achilles tendon is to lift the whole body weight and it‘s therefore the toughest and strongest of human tendons (Palastanga, et al. 2010). The Achilles tendon is absent in Australopithecus and modern apes (Bramble and Lieberman 2004). It is likely to have originated in Homo over 3 million years ago. The Achilles tendon in humans is very long, making about 65% of the total muscle length. In quadrapedal animals, including gorillas orang-utans and chimpanzees (Sellers and Williams 2007), this tendon is a lot shorter, too short to store any elastic potential. In both humans and apes the attachment is at mid-level to the calcaneus. Therefore at some point humans have evolved to have a much longer tendon that allows them to move on their hind legs. Apes can stand on two legs but choose to walk on four. Their tendon must therefore be strong enough to stabilise them whilst doing this and to hold their weight.

COMPOSITION In a healthy state a tendon is composed of 70% water and 21% collagen, of which 95% is type I collagen providing tensile strength, and a small amount of elastin. Collagen type III and collagen type V are also present: types III and V help to regulate the diameter of the collagen type I fibril. The flexibility of the tendon is obtained by allowing the collagen fibrils partial independence. The collagen fibres have a wavy course which also contributes to their flexibility. This composition of the Achilles tendon varies to that of an ape, for example. The tendon in apes does not contain as much elastin, reducing its elasticity recoil property which is essential for efficient running. The ape tendon is stiffer allowing one-off propulsive movements, needed for moving their body weight up trees (Scott et al. 2010).

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EXERCISE It is shown that exercise strengthens a tendon by causing the synthesis of type I collagen and increases the cross-links of the collagen fibrils. Exercise increases the diameter of collagen fibres allowing them to withstand greater tensile forces as they contain a higher number of intrafibrillar covalent crosslinks (Palastanga et al. 2010). The development of the Achilles tendon may be due to the load placed on the Achilles tendon when an ape stands up. This will increase collagen production making the tendon bigger and stronger. Whilst wading through a lake, for example, the force of the water would promote the upright position and this will have to be maintained, again making the tendon stronger. As this happens over time the tendon will be getting bigger and become more able to hold these forces. The advantages of standing and moving on two feet will increase the frequency at which the tendon is being used until the tendon is strong enough to hold the body upright constantly. Early humans had a much shorter Achilles tendon than we do now, this would not have had much effect on their walking, but running would be greatly affected (Highfield and Fleming 2007). Efficient running is needed to move from a herbivorous diet to a carnivorous diet where hunting skills are needed.

THE ORIGIN OF BIPEDALISM It has been suggested that humans evolved from an arboreal primate, suggesting the upright posture originated in trees rather than on the ground (Meldrum and Hilton 2004). There are many theories suggesting the origin of bipedalism, including the postural feeding hypothesis in which apes stood on two feet to pick fruit from trees (Hunt 1996). The behavioural model suggests the male will hunt and bring food back to the female and offspring. If they are better at bipedal locomotion they will bring back more food and the offspring will survive (Lovejoy 1981). Another theory is that the pressure of a hot climate forced the upright stance as this causes greater heat loss and decreased heat gain. Standing upright will put the body higher up where the air will be cooler and the amount of direct sunlight onto the skin will be reduced (Wheeler 1991). There is an adaptationist hypothesis that the reduced energy cost of upright walking would have provided advantages by decreasing the energy cost of foraging. Bipedalism uses less energy than quadrupedal knucklewalking (Tyler 2007). Animals often stood on two feet to appear a

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threat to other animals, another theory suggests bipedalism is an extension of this (Fleagle 1999).

ADVANTAGES OF BIPEDALISM The change from quadrapedal to bipedal locomotion is largely attributed to the change of the Achilles tendon, as well as other physical factors such as a narrower hip, straighter back and others (Tyler 2007). Bipedal locomotion has many benefits over quadrapedal locomotion such as having the upper limb free to carry things. Although bipedalism isn‘t what freed the hands for activities, sitting was, it did allow things to be carried whilst moving (Meldrum and Hilton 2004). This has allowed humans to carry food away from the site it was found in, to a safer location. This will stop the risk of predators whilst eating and will inhibit other animals from eating their food. They can also carry water, allowing them to hunt in dry land, which was previously inaccessible (Aiello and Dean 1990). As well as carry water they could carry their young allowing early humans to travel further for food. As the human brain developed humans began to use their hands to make and carry things such as tools to help with hunting. The upright stance of bipedalism means they can walk through deeper rivers and can see over long grass and bushes. All of these will increase their chances of catching prey and they should not go without food. Being highly nutritional will increase strength allowing them to further their hunting and other skills. Being bipedal minimises the amount of direct sunlight onto the skin at midday reducing the chance of heat stress especially on the brain. Respiration in quadrupeds is linked to upper limb activity, whereas for humans it is not. This means our respiration is independent of our speed, allowing us to run long distances by reducing the problems associated with thermal stress and heat exhaustion (Meldrum and Hilton 2004).

ENERGY EXPENDITURE In order to stand upright the centre of gravity must fall into the rectangle formed by the feet. The posture muscles must maintain balance to keep the centre of gravity in this rectangle. In humans this can be done by the iliofemoral ligament and the cruciate ligaments of the knees. Due to the small

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parameters of the body, only small adjustments need be made. This reduces the oxygen consumption needed to maintain an upright posture. A quadruped has a much larger rectangle in which its centre of gravity must fall into, which makes it easier to remain upright. However, the legs of a quadruped must be kept flexed to stand, this requires continuous muscle activity. Bipedal standing therefore has smaller oxygen consumption than quadrupedal standing. There is a lot more energy expenditure by a chimpanzee on two feet than a bipedal human. The bent-legged chimpanzee is very inefficient because it requires constant use of the hamstrings, the quadriceps and the gluteal muscles to keep the hip and knee joint from collapsing under the weight of the body (Aiello and Dean 1990). This shows our bipedal posture is very energy efficient.

ENDURANCE RUNNING The Achilles tendon has reinvented the way we move, allowing us to maintain an upright posture. Compared to other animals, which do not have Achilles tendons and are quadrapedal, we have a much lower top running speed. This may be due to the decreased muscle mass. However, humans can sustain running over much longer distances compared to other animals. For example, in a distance race a trained human can out run a horse (Venton 2010). This is likely to be due to the Achilles tendon allowing us to run efficiently. It acts like a spring to store and release energy. It has elastic potential which, when combined with the leg muscles, can give very efficient force production (Scott and et al. 2010). Stretching a tendon, as when running, produces a store of elastic energy, since tendons have low mechanical hysteresis, the majority of this energy is returned during the recoil. Thus saving energy that would otherwise be needed to propel the body forward. Other primates do not have an Achilles tendon like ours, and are poor runners. It would therefore appear that we have sacrificed speed for endurance.

ELASTICITY OF THE TENDON Bill Sellers designed a computer model of human running (model A) (Urquhart and Sellers 2000). He then made all the tendons in the body 100 times stiffer (model B). This tripled the energy usage and almost halved their top speed. He then restored the Achilles tendon back to normal stiffness

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(model C) this allowed them to run a lot faster but still not as fast as a normal human with full elasticity in all tendons. The other design was of a human with all elastic tendons except the Achilles tendon which remained stiff (model D). Model C ran faster than models B or D. This shows the importance of elasticity in the Achilles tendon for efficient, high-performance running. Elasticity minimises the total energy spent by the body and increases the power of the push-off. Cyclic tensile loading, as in running, has been shown to significantly increase the elastic modulus compared to underused tendons (Palastanga et al. 2010). Model A ran faster than model C showing elasticity in all tendons is important and not just in the Achilles tendon.

OTHER BIPEDAL ANIMALS The bipedal ostrich is able to run up to 40mph for a short distance and can maintain a speed of 30mph over long distances (Theys 2009). A condor, on the other hand, which is also a large bird but is not adapted to land running, can only run very slowly and only for short distances. Ostriches have long (about 80cm), thin tendons of the gastrocnemius and digital flexors (Rubenson et al. 2004). This allows the tendon to be more compliant than the human equivalent, the Achilles tendon. This means to stretch the tendon by a given amount, the ostrich will not need as much muscle force as a human would require to stretch the tendon by the same amount. This tendon is well suited to elastic energy storage and it is this tendon which generates most of the force needed during locomotion (Smith et al. 2006). In the condor however, this tendon no longer exists (Raikow et al. 1979).

DISADVANTAGES OF THE ACHILLES TENDON The structure of tendons gives them high tensile strength in the direction of the collagen fibre. For the Achilles tendon, this will be vertically to withstand forces produced during locomotion. This means, however, in the other direction, horizontally, it will be a lot weaker as only a few collagen fibres will run this way, leaving the tendon vulnerable to lateral forces. Whilst running off-road may be better for the tendon in terms of stress, it also gives uneven terrain which places greater shear loads onto the tendon which will act sideways (2010b).

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ANATOMICAL POSITION A number of properties of bipedal locomotion put the Achilles tendon under strain, making it vulnerable to both sudden and chronic injuries. This includes its anatomical position as it is the first structure to take up the impact forces involved with many activities. The upright stance of a biped puts the foot at a right angle to the leg thus generating heavy torque (Scott et al. 2010).

MUSCLE FUNCTIONS The different functions of the muscles soleus and gastrocnemius, which make up the Achilles tendon, add to its vulnerability. The soleus plantar flexes the foot and mainly acts in posture maintenance to ensure we do not fall forward when standing; it thus contains mainly slow twitch fibres. The gastrocnemius on the other hand, flexes the knee as well as plantar flexing the foot and contains mainly fast twitch fibres necessary for propulsive movements needed during sprinting and jumping. The fibres of gastrocnemius attach to the lateral part of the calcaneus and the fibres of soleus to the medial part. When the knee is flexed it can rotate; as the gastrocnemius crosses the knee joint, the tendon derived from these fibres can be twisted relative to the fibres of soleus. This causes the gastrocnemius fibres to cut into the soleus fibres causing a ‗sawing‘ action on them (Theobald et al. 2007).

HEAT STRESS Stretching of the tendon during running will cause the energy to be released during recoil. Some of this energy is lost as heat. The amount of heat lost during a single stretch cycle is small and does not affect the tendon. However, if this is done repeatedly as in running or walking, the heat may accumulate and cause thermal damage and injury to the tendon, predisposing the tendon to rupture. Hyperthermia may be involved in exercise related trauma (Scott et al. 2010).

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OVERUSE INJURY During running the Achilles tendon can transmit up to seven times body weight compared to its normal half body weight that it transmits whilst standing. Running and standing on two legs compared to four legs increases the strain on the tendon as each one will be carrying more weight. This will make the Achilles tendon more prone to overuse injuries. The most common overuse injury being tendinosis (Scott et al. 2010). When walking on two legs, injury to the Achilles tendon will have a larger negative effect than when walking on four legs. If one leg is injured, for a biped this is 50% of their legs which would have a greater effect than 25% as would be seen in a quadruped. The hypovascularity of the Achilles tendon means it has a low healing capacity and therefore takes a long time to repair itself (Benazzo 2000). This lack of blood flow and oxygen predisposes the tendon to injury (Scott et al. 2010). There are a number of intrinsic properties of the Achilles tendon which makes it more susceptible to chronic overuse injuries. For example, the Achilles tendon attaches medially to the subtalar joint axis, producing a supinatory force. Excessive pronation will cause internal tibial rotation, moving the tendon medially. There may be supination of the subtalar joint, to counteract this. This force can cause microtears in the Achilles tendon. This further decreases the blood flow to the tendon, over time this can lead to degeneration (2010a).

IMMOBILISATION Immobilsation of the tendon during a sedentary lifestyle causes it to atrophy (Scott et al. 2010). Both the density and size of the collagen fibres decreases causing impaired tensile strength. When the tendon is then used for unaccustomed exercise, it is very prone to rupture as it has lost its strength. It therefore appears the Achilles tendon has to be used to the correct degree. If it is overused it is prone to overuse injuries such as tendinosis and if it is not used it becomes prone to rupture.

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AGE Degeneration of the tendon occurs with ageing. The amount of collagen type III in the tendon increases with age which causes a decrease in collagen fibril diameter. The amount of collagen crosslinks increases (Torbert 2010), increasing the stiffness and decreasing the elasticity of the tendon, making it more likely to rupture, as it is less resistant to tensile forces (Woo et al. 2000). Low-load training can increase the elasticity of the tendon. Ageing of the tendon will occur faster in a biped than a quadruped as it is being used more frequently.

CONCLUSION The modern anatomy of a human Achilles tendon puts many intrinsic stresses onto the structure. These can predispose the tendon to injury. It is also liable to degeneration with age. There are precautions that can be taken to minimize the risk of injury, such as wearing padded, correctly fitting shoes or gradually increasing exercise intensity, rather than suddenly. A balance is required between a sedentary lifestyle in which tendon ruptures are common and an athletic lifestyle which may lead to tendinosis. The benefits of bipedalism must be weighed up against the probability of injury. In our opinion, the benefits we have gained through bipedalism, such as finger dexterity and all the skills it has allowed us to develop, far outweigh the risk of injury.

REFERENCES Achilles Tendon Injuries. Simple Foot Solutions (2010a). 14-10-2010a. [Electronic Citation www.simplefootsolutions.com/achilles-tendon-injury] Aiello, L. & Dean, C. (1990). "Bipedal Locomotion and the Postcranial Skeleton," in An Introduction to Human Evolutionary Anatomy, L. Aiello & C. Dean, eds., Elsevier. Benazzo, F. (2000). "An Operative Approach to Achilles Tendinopathy," Sports Medicine and Arthroscopy Review, vol. 8, no. 1. Bramble, D. M. & Lieberman, D. E. (2004). "Endurance Running and the Evolution of Homo," Nature, vol. 432.

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Fleagle, J. G. (1999). "Hominids, The Bipedal Primates," in Primate Adaptation and Evolution, 2nd edn, Elsevier. Highfield, R. & Fleming, N. (2007). Ancient Humans walked but 'Struggled to Run.' The Telegraph. 11-9-2007. [In Press] Hunt, K. D. (1996). "The postural feeding hypothesis: an ecological model for the evolution of bipedalism," South African Journal of Science, vol. 92, (77-90). Lovejoy, C. O. (1981). "The Origins of Man," Science, vol. 211, no. 4480, (341-350). Meldrum, D. J. & Hilton, C. E. (2004). From Biped to Strider: The emergence of Modern Human Walking, Running and Resource Transport. Palastanga, N. et al. (2010). Anatomy and Human Movement, 5th edn, Butterworth Heinemann. Raikow, R. J. et al. (1979). "The Evolutionary Re-Establishment of a Lost Ancestral Muscle in the Bowerbird Assemblage," The Condor, vol. 81, no. 2, (203-206). Rubenson, J. et al. (2004). "Gait selection in the Ostrich: mechanical and metabolic characteristics of walking and running with and without an aerial phase," The Royal Society. Scott, A. et al. (2010). Tendinopathy in Athletes Blackwell. Sellers, W. & Williams, R. (2007). Development of the Modern Human, The Science Show, (Radio). Smith, N. C. et al. (2006). Muscle Architecture and functional anatomy of the pelvic limb of the ostrich. Sports injuries: (2010b). Achilles Tendinitis. Peak Performance, Sporting Excellence. [Electronic Citation] Theobald, D. et al. (2007). The Achilles Tendon Springer. Theys, M. (2009). The Fastest Animals in Africa. Africa Freak. 12-11-2009. [Electronic Citation] Torbert, J. T. Achilles Tendon Rupture. & Veillette, C. (2010). Orthopaedia: Collaberative Orthopaedic Knowledge Base. 11-6-2010. [Electronic Citation] Tyler, D. A. (2007). Design Perspective on Human Bipedalism. Science Literature. [Electronic Citation] Urquhart, J. & Sellers, W. (2000). How Humans Run. New Scientist. [Video Recording] Venton, D. & Achilles Tendon A. (2010). Blessing, Not A Curse. International Science Grid This Week. 6-10-2010. [Magazine Article]

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Wheeler, P. E. (1991). The thermoregulatory advantages of hominid bipedalism in open equatorial environments: the contribution of increased convective heat loss and cutaneous evaporative cooling. Journal of Human Evolution 21[2], 107-115. [Magazine Article] Woo, S. L. Y. et al. (2000). Orthopaedic Basic Science Biology and Biomechanics of the Musculoskeletal System., 2nd edn.

In: Achilles Tendon and Ankle Injuries ISBN: 978-1-63483-484-1 Editor: Arthur Adams © 2015 Nova Science Publishers, Inc.

Chapter 4

THE BIOMECHANICS OF ANKLE JOINT AND ITS RELEVANCE TO TOTAL ANKLE REPLACEMENT M. R. Nannaparaju and W. S. Khan UCL Institute of Orthopaedics and Musculoskeletal Sciences, Royal National Orthopaedic Hospital, Stanmore, London, UK

ABSTRACT Ankle joint is one of the most complex joints in the human body. Anatomists, biomechanical engineers, and clinicians have studied the foot and ankle complex for centuries. Each discipline has provided its unique insight into the structure and function of this unit. The differences of approaches have also led to varying interpretations, resulting in considerable confusion regarding the operation of this complex. The purpose of this article is to discuss the basic biomechanical characteristics and forces acting on the ankle under static conditions and their influences on artificial total ankle replacement designs.

INTRODUCTION The ankle joint has been an area of study for centuries. It is a complex joint form by the articulation of many bones and helps in transforming body load onto the foot. It is one of the most important joints of the body as pain,

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discomfort and other pathology may have significant impact on the functional life of an individual. Due to its structure, the biomechanical forces acting on the ankle are very different and complicated to those acting on the hip or knee. Having a clear understanding of these is very important for a clinician to diagnose the ankle pathology and choose the appropriate means of treatment. This article discusses the anatomy, biomechanical aspects of the ankle and their implications in designing total ankle replacement prosthesis.

ANATOMY OF THE ANKLE JOINT The ankle joint complex consists of three joints namely the ankle joint (or talocrural), the subtalar joint and the midtarsal joints. The ankle joint consists of three bones namely, the tibia, fibula, and talus (Figure 1). The average thickness of the ankle cartilage is approximately 1.6 mm whereas the thickness of the knee cartilage is 6–8mm (Shepherd and Seedhom 1999). The ankle joint experiences higher forces than any other articulation. During the stance phase, the ankle joint experiences forces of magnitude 5 to 7 times the body weight (BW) whereas it is 3 to 4BW in the knee joint and 2 to 3BW in the hip joint (Stauffer et al. 1977). Although the surface area of the ankle joint is similar to that of the hip and knee joints,the contact area during loading is only one-third of these (Kimizuka et al., 1980; Brown and Shaw, 1983; Ihn et al. 1993). The ankle joint gains its stability from bony congruence, the joint capsule as well as ligamentous support.Medial ankle stability comes from the medial malleolus and the deltoid ligament, which is by far the strongest stabilizer of the ankle with a tensile strength of 714N. CFL is the strongest ligament on the lateral side with a tensile strength of 346N (Attarian et al. 1985).

GAIT CYCLE The proper concept of gait cycle is very important to understand the biomechanics of ankle. Gait cycle has two different phases, the stance phase and the swing phase. The stance phase constitutes about 60% of the gait cycle in order of occurrence it is divided into these divisions : heel strike, foot flat, heel rise, pushoff and toeoff. The swing phase takes up the other 40% of the gait cycle and is divided into acceleration, toe clearance, and deceleration. Muscular activity during gait affords control of the foot such that the centre of

The Biomechanics of Ankle Joint and Its relevance to Total Ankle … 79 gravity of the body progresses smoothly forward without excessive frontal plane motion. Gait may also be specifically considered in relation to foot motion in the sagittal plane using the rocker theory (Perry 1992). During the first rocker the ankle plantarflexes after heel-strike bringing the forefoot into contact with the ground. Ankle plantarflexion is brought under control by eccentric (lengthening) contraction of the extrinsic anterior compartment. Next during the second rocker the ankle dorsiflexes as the centre-of-gravity of the body moves over the joint muscles. The final third rocker occurs as the metatarsophalangeal joints dorsiflex in preparation for toe-off. Here the windlass mechanism is activated, tensioning the plantar fascia under the metatarsophalangeal joints and transforms into a rigid lever which can transmit a propulsive force to the ground.

(http://www.szote.u-szeged.hu/Radiology/Anatomy/skeleton/ankle1.htm) 1. Fibula 2. Tibia 3. Distal tibiofibular joint 4. Malleolar fossa malleolus 6. Ankle joint 7. Medial malleolus 8. Talus Figure 1. The anteroposterior view of ankle joint.

5. Lateral

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BIOMECHANICS OF THE STATIC ANKLE Patil et al. (1993) developed a 2D finite element(FE) model of a normal foot and simulated the joint forces acting on it to determine the ground reaction forces in different stages of the gait cycle. In their study the foot bone material was assumed to be isotropic, homogenous and linearly elastic with a young‘s modulus of 7.3Gpa and poisson‘s ratio of 0.3. Table 1 shows the ankle joint forces, ground reaction forces, highest principal tensile stresses, highest principal compressive stress, and highest vonMises stress contour during various phases of gait cycle (Patil et al.,1993). This data reveals that the ankle joint exerts almost twice the magnitude of ground reaction forces to maintain stability during each phase of gait cycle. Although a 2D model gives us a good understanding of the distribution of forces (ankle joint force, ground reaction force) and stresses (highest principal tensile, compressive stresses and vonMises stress contour) it cannot effectively depict the inticacies of the ankle joint complex. Gefen et al. (2000) designed a 3D foot model using MRIs from the feet of a 27 year old male, a 25 year old female and a cryosection from a 39 year ols male. They used a young‘s modulus of 7.3Gpa for the foot bones and 1Mpa for cartilage. The finite element method was selected for numerical analysis of the model. The results are shown in Tables 2 and 3 which show the areas experiencing increased vonMises stresses and the loads acting on the ankle joint during various subphases of gait cycle respectively. Table 1. Ankle Joint stresses during various subphases of gait

Model phase

Ankle joint force, N

Ground reaction force, N

Highest principal tensile stress, %a

Highest principal compressive stress, %a

Midstance

2.0W

600

52.0

38

Highest vonMises stress contour, %a 32.5

Heel phase

2.25W

961(0.77W)

--

24

22.0

Push-off

3.5W

904.8(1.51W)

82.5

61

60.0

W-Body weight of a person weighing 600N. a-Percentage of yield stress of the bone material.

The Biomechanics of Ankle Joint and Its relevance to Total Ankle … 81

Initial contact Heel strike Midstance Forefootcontact Push-off Toe-off

Plantar calcaneus Medial Calcaneus Posterior calcaneus Posterior calcaneus Posterior calcaneus Posterior calcaneus

0.45

1.21

1.24

Posterior & medial calceneus --

3.48

Dorsal talus

2.72

3.18

Dorsal talus

3.80 0.61

Maximum stress value (Mpa)

Location of stress

Maximum stress value (Mpa)

Location of stress

Location of stress

Sub-stage

Maximum stress value (Mpa)

Table 2. Areas experiencing increased vonMises stresses during gait

Dorsal talus -

1.07

2.61

3.37

Lateral talus -

Dorsal talus

3.55

-

-

Dorsal talus

1.04

-

-

--

-

-

Table 3. Loads acting on ankle joint during various subphases of gait cycle Region Ankle joint load

Initial contact 675

Heel strike, N 1350

Midstance, N 2100

Forefoot contact, N 2550

Pushoff, N 3000

Toeoff, N 300

Cheung et al. (2005) also used a 3D finite element model to study the peak vonMises stresses, during balanced standing, in the talus and calcaneum. They used the MRI of right foot from a normal male aged 26, height 174cm and weight 70 kg. Young‘s modulus of 7.3Gpa and poisson‘s ratio of 0.3 for foot bones, 1Mpa and 0.4 for cartilage, 260Mpa and 0 for ligaments were used respectively. The nominal stress values were multiplied by a factor of 2, 3, and 5 to investigate the biomechanical effect of soft tissue stiffening in different stages. The results are summarized in Table 4 which show that with a 5% increase in tissue stiffness there is a reduction in the peak vonMises stress of 0.78Mpa at the talus and 0.95Mpa at the calcaneum.

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M. R. Nannaparaju and W. S. Khan Table 4. vonMises stress of the foot during standing Bone Talus Calcaneum

Normal 2.89 3.94

F2 2.47 3.50

F3 2.33 3.27

F5 2.11 2.99

F2,F3 and F5 correspond to simulations of 2,3and 5 times the stiffness of normal tissue.

As ligaments play a vital role in various motions of the ankle joint, the relationship between the changes in ligament strain during these motions is very important. Renstrom et al. (1988) used Hall effect transducers to determine the strain in the anterior talofibular and calcaneofibular ligaments. Measurements of 5 cadaveric ankles were made in neutral position and during the motion from 10deg dorsiflexion to 40deg plantar flexion. It was found that the strain increased in the anterior talo fibular ligament when the ankle motion ranged from 10deg dorsiflexion through 40deg plantarflexion to 3.3% as well as in the calcaneofibular ligament with supination and eversion. The strain was found to decrease in the calcaneofibular ligament with increased plantarflexion and in the anterior talofibular ligament with eversion to 1.9%. In conclusion, these two ligaments were found to be synergistic, that is when one of the ligaments is strained the other one is relaxed and vice versa. Another important parameter which has been widely studied is the stress change in the articulating surface of the tibio-talar (TT) interface during various motions of the joint. To study the relationship between the stress changes in the TT interface, geometry of the articulating surface of the TT interface was modelled through an experiment conducted with six normal cadaveric ankles with a material testing system, Bionix MTS (Tochigi et al. 2006).The contact stress at the TT articulation was monitored by realtime contact stress sensor (Tekscan 5033). The ankles were loaded with the normal body weight (primary axial force). Also, the anterior/posterior shear forces, the inversion/ eversion torques and the internal/external rotation torque were applied independently while the other two were constrained. From the experiment it was found that the anterior/posterior shear forces produce reproducible positive changes (elevation in the values) in the anterior/posterior regions respectively. Similarly, the version torques produce corresponding reproducible positive changes in the medial/lateral regions while internal/external rotation torques produce reproducible positive changes in two diagonal locations namely anterolateral and posteromedial or anteromedial, and posterolateral. With these forces and torques as input, a model of the

The Biomechanics of Ankle Joint and Its relevance to Total Ankle … 83 articulating surface was generated using MATLAB, version 7.0. The talus consists of two domes adjacent to each other on its upper surface in the frontal plane (Saltzman et al. 2005). Hence the surface was modelled as two adjacent spheres with radii of 25 mm and the distance between the centres of the spheres was 20 mm. The radius of the sphere is taken to be 25 mm since the radius of the talar dome is 21.3 ± 1.8 mm. The analysis of the articulating surface revealed that the changes were seen with respect to altered external load to retain stability. The contribution of the articulating surface to the joint stability was 70% of the anterior/posterior stability, 50% of inversion/eversion stability and 30% of internal/external rotation stability.

APPLICATION OF BIOMECHANICS IN DESIGNING TOTAL ANKLE REPLACEMENTS TAR‘s were first developed in early 1970‘s (Alvine 2000).They are broadly discussed as the first and second generation prostheses.

FIRST GENERATION TAR’S The first generation TARs were of two types namely constrained and unconstrained. Constrained prostheses limit motion to the sagittal plane. They were typically spherical, spheroidal, conical, cylindrical or sliding cylindrical in shape (Lewis 1994). They provided greater stability (Waugh et al. 1976), minimized impingement of the malleoli against the talus (Conti and Wong 2001), and decreased wear of the polyethylene insert due to larger contacting surfaces. The only disadvantage of the prostheses was increased stresses at the bone cement implant interfaces leading to early failure due to aseptic loosening. Examples of this prostheses type are Imperial College London Hospital (ICLH), Conaxial, St.Georg/ Buchholz. Unconstrained prostheses were typically trochlear, bispherical, concaveconvex, and, convexconvex in shape (Lewis 1994). They provided improved range of motion but stability was greatly reduced.The results of unconstrained prostheses proved to be a total failure (Evanski and Waugh 1977). Though the constrained prostheses produced comparatively better initial results they also proved to be discouraging.

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SECOND GENERATION TAR’S The second generation prostheses were developed to overcome the disadvantages and complications associated with the first generation prostheses (Thomas and Timothy 2003). These implants were intended to reproduce the anatomical characteristics of the ankle joint, joint kinematics, ligament stability and mechanical alignment. The sliding and rotational motions of the ankle joint were achieved by the two or three component designs. Agility ankle is the prototype of the two component semiconstrained design. The incongruency between the talar and tibial articulations in this design allows sliding as well as the rotational motions that mimic ankle kinematics (Saltzman et al. 2000). Examples of threecomponent TARs are Scandinavian total ankle replacements (STAR), Mobility, Ankle evolutive system (AES), Bologna Oxford (BOX) TAR and Eclipse Total Ankle Implant. Michael et al. (2008) compared the long term outcomes of the second generation prostheses and concluded that the survivability rate of TAR models is influenced by various factors such as component loosening, component migration, deep or superficial infection, delayed wound healing, nonunion of bones, intraoperative fractures of malleoli, tibia, or talus. Out of these, the major reason for TAR failure is the loosening of components, the cause being either malposition of the components during initial procedure or wear debris of the cement (polymethyl methacrylate, PMMA) particles that leads to abrasive wear in the polyethylene liner. Though the clinical outcomes of TARs are reported extensively, the reasons behind the failure are not explained. A broad comparison of their outcomes revealed that the results of most of the existing TAR models are unsatisfactory (Leardini et al., 1999a,b; Leardini 2001) developed A computer based geometrical model, fourbar linkage (4BL), to describe the ankle motion in passive conditions in the sagittal plane. They concluded that the shape of the articulation surface compatible with the ligament rotation during various ankle motions was an arc of a circle which is polycentric and polyradial in nature. Michael et al. (2008) developed three models of TAR‘s based on the above model but further analysis is to be carried out to review the biomechanics of the ankle after replacement with these designs.

The Biomechanics of Ankle Joint and Its relevance to Total Ankle … 85

CONCLUSION Understanding the complex anatomy and the effects of the different biomechanical forces acting on the ankle joint is very important for orthopaedic practice. A clear knowledge of these aids the correct decision making in treating ankle pathology. The unique bony structure and multi ligamentous configuration render the stability needed in ankle which exerts almost twice the magnitude of ground reaction forces during each gait cycle phase. As it is very difficult to mimic this natural configuration with an artificial joint, research is ongoing to design a total ankle replacement system with satisfactory long term results.

REFERENCES Alvine, F. G. (2000). In: Myerson, M.S. (Ed.), Total Ankle Arthroplasty. In: Foot and Ankle Disorders, vol. 2. Saunders, Philadelphia, p. 1087. Attarian, D. E., McCrackin, H. J., Devito, D. P., McElhaney, J. H. & Garrett, Jr. W. E. (1985). Biomechanical characteristics of human ankle ligaments. Foot Ankle, Oct, 6, 54e8. Brown, T. D. & Shaw, D. T. (1983). In vitro contact stress distributions in the natural human hip. Journal of Biomechanics, 16, 373–384. Stauffer, R. N., Chao, E. Y. S. & Brewster, R. C. (1977). Force and motion analysis of the normal, diseased, and prosthetic ankle joint. Clinical Orthopedics, 127, 189–196. Cheung, J. T. M., Zhang, M., Leung, A. K. L. & Fan, Y. B. (2005). Threedimensional finite element analysis of the foot during standing — a material sensitivity study. Journal of Biomechanics, 38, 1045–1054 Conti, S. F. & Wong, Y. S. (2001). Complications of total ankle replacement. Clinical Orthopaedics and Related Research, 391, 105–114. Evanski, P. M. & Waugh, T. R. (1977). Management of arthrodesis of the ankle: An alternative to arthrodesis. Clinical Orthopaedics and Related Research, 122, 110–115 Gefen, A., Ravid, M. M., Itzchak, Y. & Arcan, M. (2000). Biomechanical analysis of the three dimensional foot structure during gait: A basic tool for clinical applications. Journal of Biomechanical Engineering, 122 (6), 630–639

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Ihn, J. C., Kim, S. J. & Park, I. H. (1993). In vitro study of contact area and pressure distribution in the human knee after partial and total meniscectomy. International Orthopaedics, 17 (4), 214–218. Kimizuka, M., & Kurosawa H. Fukubayashi. (1980). Load bearing pattern of the ankle joint: Contact area and pressure distribution. Archives of Orthopaedic and Trauma Surgery, 96, 45–49. Leardini, A., O‘Connor, J. J., Catani, F. & Giannini, S. (1999a). A geometric model of the human ankle joint. Journal of Biomechanics, 32, 585–591. Leardini, A., O‘Connor, J. J., Catani, F., Stagni, R. & Giannini, S. (1999b). Lever arm lengths of the flexor and extensor muscles at the ankle joint complex. In: Proceedings of the 45th Annual Meeting of the orthopaedic Research Society, Anaheim, CA. p. 216. Leardini, A. (2001). Geometry and mechanics of the human ankle complex and ankle prosthesis design. Clinical Biomechanics, 16 (8), 706–709. Lewis, G. (1994). The ankle joint prosthetic replacement: Clinical performance and research challenges. Foot and Ankle International, 15 (9), 471–476 Michael, J., Golshani, A., Gargac, s. & Goswani, T. (2008). Biomechanics of the ankle joint and clinical outcomes of total ankle replacement. Journal of the mechanical behaviour of biomedical materials, 276-294. Patil, K. M., Braak, L. H. & Huson, A. (1993). Stresses in a simplified two dimensional model of a normal foot — A preliminary analysis. Mechanics Research Communications, 20 (1), 1–7. Perry J. (1992). Gait analysis: normal and pathological function. Thorofare, NJ: SLACK Inc. Renstrom, P., Wertz, M., Incavo, S., Pope, M., Ostgaard, H. C., Arms, S. & Haugh, L. (1988). Strain in the lateral ligaments of the ankle. Foot Ankle, 9 (2), 59–63. Saltzman, C. L., Salamon, M. L., Blanchard, G. M., Huff, T., Hayes, A., Buckwalter, J. A. & Amendola, A. (2005). Epidemiology of ankle arthritis: Report of a consecutive series of 639 patients from a tertiary Orthopaedic center. Iowa Orthopaedic Journal, 25, 44–46. Saltzman, C. L., McIff, T. E., Buckwalter, J. A. & Brown, T. D. (2000). Total ankle replacement revisited. Journal of Orthopaedic & Sports Physical Therapy, 30 (2), 56–67. Shepherd, D. E. & Seedhom, B. B. (1999). Thickness of human articular cartilage in joints of the lower limb. Annals of the Rheumatic Diseases, 58 (1), 27–34.

The Biomechanics of Ankle Joint and Its relevance to Total Ankle … 87 Thomas, R. H. & Timothy, R. D. (2003). Ankle arthritis. Journal of Bone & Joint Surgery, 85, 923–936. American Volume. Tochigi, Y., Rudert, M. J., Saltzman, C. L., Amendola, A. & Brown, T. D. (2006). Contribution of articular surface geometry to ankle stabilization. Journal of Bone & Joint Surgery, 88, 2704–2713. American Volume. Waugh, T. R., Evanski, P. M. & McMaster, W. C. (1976). Irvine ankle arthroplasty. Prosthetic design and surgical technique. Clinical Orthopaedics, 114, 180–184.

BIBLIOGRAPHY Managing and treating common foot and ankle problems LCCN: 2014381877 Managing and treating common foot and ankle problems / editor, John A. Dipreta; consulting editors Douglas S. Paauw, Edward R. Bollard. Published/Produced: Philadelphia, Pennsylvania: Elsevier, [2014] Description: xviii, [181]-389 pages: illustrations (some color); 24 cm. ISBN: 9780323263986 (hbk) 0323263984 (hbk) LC classification: RD781. M36 2014 Related names: Dipreta, John A., editor Contents: The foot and ankle examination -- Gait: the role of the ankle and foot in walking -- Nail and skin disorders of the foot -- Hallux valgus -- Metatarsalgia, lesser toe deformities, and associated disorders of the forefoot -Arthritides of the foot -- Ankle arthritis: review of diagnosis and

operative management -- Officebased management of adultacquired flatfoot deformity -- The cavus foot -- Ankle sprains and instability -- Achilles tendon disorders -- Plantar heel pain -Outpatient assessment and management of the diabetic foot. Subjects: Foot--Abnormalities-Treatment. Foot--Diseases-Treatment. Arthritis--Treatment. Foot Diseases--therapy Notes: "March 2014" Includes bibliographical references and index. Series: Medical clinics of North America, 0025-7125; volume 98, number 2 Medical clinics of North America; 98, no.2. Minimally invasive surgery for achilles tendon disorders in clinical practice LCCN: 2012951635 Minimally invasive surgery for achilles tendon disorders in clinical practice / [edited by] Nicola Maffuli.

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Bibliography Published/Created: New York: Springer, 2012. Description: p. cm. ISBN: 9781447144977 (soft cover: alk. paper)

Rehabilitation for the postsurgical orthopedic patient LCCN: 2012031888 Rehabilitation for the postsurgical orthopedic patient / [edited by] Lisa Maxey, Jim Magnusson. Edition: 3rd ed. Published/Created: St. Louis, Mo.: Elsevier/Mosby, c2013. Description: xiv, 650 p.: ill. (some col.); 29 cm. ISBN: 9780323077477 (hardcover: alk. paper) 0323077471 (hardcover: alk. paper) LC classification: RD736.P47 R44 2013 Related names: Maxey, Lisa. Magnusson, Jim. Contents: Part One: Introduction -- -- Pathogenesis of Soft Tissue and Bone Repair -Soft Tissue Healing Considerations After Surgery -- -Part Two: Upper Extremity -- -Acromioplasty -- Anterior Capsular Reconstruction -Rotator Cuff Repair -- Superior Labral Anterior Posterior Repair - Total Shoulder Arthroplasty -Tennis Elbow: Extensor Brevis Release and Lateral Epicondylectomy -Reconstruction of the Ulnar Collateral Ligament with Ulnar Nerve Transposition -- Platelet Rich Plasma Injection (PRP) for the Ulnar Collateral Ligament --

Surgery and Rehabilitation for Primary Flexor Tendon Repair in the Digit -- Carpal Tunnel Syndrome -- Transitioning the Throwing Athlete Back to the Field -- -- Part Three: Spine -- -Anterior Cervical Discectomy and Fusion -- Posterior Lumbar Arthroscopic Discectomy -Lumbar Spine Fusion -- Lumbar Spine Disc Replacement -- -- Part Four: Lower Extremity -- -- Total Hip Arthroplasty -- Total Hip Mini Invasive -- Hip Arthroscopy -- Open Reduction and Internal Fixation of the Hip -- Anterior Cruciate Ligament Reconstruction -- Arthroscopic Lateral Retinaculum Release -Meniscectomy and Meniscal Repair -- Autologous Chondrocyte Implantation -Patella Open Reduction and Internal Fixation -- Total Knee Arthroplasty -- Lateral Ligament Repair of the Ankle -- Open Reduction and Internal Fixation of the Ankle -- Ankle Arthroscopy -- Achilles Tendon Repair -- Surgical Correction for Hallux Valgus Deformity -Transitioning the Jumping Athlete -- Transitioning the Running Athlete. Subjects: Physical therapy. Orthopedic surgery--Patients--Rehabilitation. Postoperative care. Physical Therapy Modalities. Postoperative Care--

Bibliography rehabilitation. Orthopedic Procedures--rehabilitation. Notes: Includes bibliographical references and index. Sports injuries sourcebook: basic consumer health information about sprains and strains, fractures, growth plate injuries, overtraining injuries, and injuries to the head, face, shoulders, elbows, hands, spinal column, knees, ankles, and feet ... / edited by Sandra J. Judd. Edition: 3rd ed. Published/Created: Detroit, MI: Omnigraphics, c2007. Description: xix, 651 p.: ill.; 24 cm. ISBN: 9780780809499 (hardcover: alk. paper) 0780809491 (hardcover: alk. paper) LC classification (full): RD97 .S736 2007 LC classification (partial): RD97 Related names: Judd, Sandra J. Summary: "Provides basic consumer health information about the causes of sports injuries, their prevention, and treatment options. Includes index, glossary of related terms, and other resources"--Provided by publisher. Contents: pt. I. Sports and health -- 1. Sports and exercise sometimes lead to injury -- 2. Sports and the young child: risks and benefits -- 3. Questions and answers about sports nutrition -- 4. Sprains and strains -- 5. Fractures -- 6. Growth plate

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injuries -- 7. Overtraining injuries -- section 7.1. Overuse injuries: an overview -- section 7.2. Stress fractures -- 8. Heat injuries -section 8.1. Heat stress and athletic participation -- section 8.2. Hydration and hyponatremia -- 9. Sudden cardiac arrest in athletes -- 10. Sports-related skin disorders -- 11. Sports injuries and arthritis -- 12. Exerciseinduced disorders -- section 12.1. Exercise-induced urticaria (hives) -- section 12.2. Exercise-induced asthma -- 13. Female athlete triad -- 14. Performance-enhancing substances -- section 14.1. Steroids -- section 14.2. Sports supplements -- pt. II. Sports injury prevention -- 15. Childhood sports injuries and their prevention -- 16. Preparticipation sports physicals -17. Emergency preparedness helps prevent serious injury -section 17.1. Developing an emergency action plan -- section 17.2. First aid for sports injuries - 18. Protective equipment -section 18.1. Wear a helmet to reduce sports-related head injuries -- section 18.2. Selecting athletic shoes -- section 18.3. Uses and abuses of orthotics -section 18.4. Sports eye protection -- section 18.5. Mouth guards -- 19. Preventing injuries in contact sports -- section 19.1. Football safety -- section 19.2.

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Bibliography How to fit football equipment -section 19.3. Preventing injuries in ice hockey -- section 19.4. Fitting hockey equipment -- 20. Team sports safety -- section 20.1. Baseball and softball safety -- section 20.2. Breakaway bases and the prevention of baseball and softball injuries -- section 20.3. Basketball safety -- section 20.4. Tips for preventing soccer injuries -- 21. Tips to improve cheerleading safety -- 22. Biking and running injury prevention -section 22.1. Preventing bicycling injuries -- section 22.2. Preventing running injuries -- 23. Preventing golf injuries -- 24. Preventing tennis injuries -- 25. Water sports safety -- 26. Winter sport safety -- section 26.1. Preventing Alpine skiing and sledding injuries -- section 26.2. Properly fitting ski boots -section 26.3. Preventing snowboarding injuries -- section 26.4. Preventing ice skating injuries -- section 26.5. Don't let winter chill your training -- pt. III. Head injuries and facial injuries -- 27. Head injuries -section 27.1. Sports-related head injuries -- section 27.2. Concussion -- 28. Facial sports injuries -- 29. Injuries to the eyes, ears, and teeth -- section 29.1. Eye injuries in sports -- section 29.2. Cauliflower ear -- section 29.3. Dental injuries -- pt. IV.

Shoulder and upper arm injuries - 30. Injuries to the shoulder -section 30.1. Questions and answers about shoulder problems -- section 30.2. Rotator cuff tears -- section 30.3. Shoulder impingement -- section 30.4. Frozen shoulder (adhesive capsulitis) -- section 30.5. Shoulder separation -- section 30.6. Shoulder dislocation -section 30.7. Shoulder sprain -section 30.8. Shoulder instability -- 31. Collarbone injuries -section 31.1. Broken collarbone - section 31.2. New techniques in the treatment of broken collarbones -- section 31.3. Rehabilitation of the broken collarbone -- 32. Injuries to the biceps -- section 32.1. Rupture of the biceps tendon -- section 32.2. Biceps tendonitis -- pt. V. Injuries to the elbows, wrists, and hands -- 33. Taking care of your hand, wrist, and elbow -- 34. Elbow injuries -- section 34.1. Throwing injuries in the elbow -section 34.2. Tennis elbow (lateral epicondylitis) -- section 34.3. Botulinum toxin as a treatment for tennis elbow -section 34.4. Golfer's elbow (medial epicondylitis) -- section 34.5. Elbow fractures -- section 34.6. Elbow fracture rehabilitation -- section 34.7. Elbow (olecranon) bursitis -section 34.8. Dislocated elbow --

Bibliography section 34.9. Ulnar nerve entrapment -- 35. Arm and wrist injuries -- section 35.1. Forearm fractures -- section 35.2. Wrist fractures -- section 35.3. Scaphoid fractures -- section 35.4. Wrist sprains -- 36. Injuries to the bones of the hand -- section 3 .1. Hand fractures -- section 3 .2. Boxer s fracture -- 37. Injuries to the fingers and thumb -- section 37.1. Extensor tendon injuries: mallet finger and boutonni re deformity -- section 37.2. Flexor tendon injuries (Jersey finger) -- section 37.3. Finger sprains -- section 37.4. Thumb sprains (skier's thumb) -pt. VI. Injuries to the back and spine -- 38. Back injuries -section 38.1. Lower back pain in athletes -- section 38.2. Lumbar strain (weight lifter's back) -- 39. Spondylolysis and spondylolisthesis -- 40. Prehospital care of the spineinjured athlete -- 41. Injuries to the neck and cervical spine -section 41.1. Neck injuries -section 41.2. Cervical spine fractures -- 42. Injuries to the spine (backbone) -- section 42.1. Spinal cord injuries -- section 42.2. Tailbone injuries -- 43. Nerve injuries: stingers and neurapraxia -- pt. VII. Injuries to the trunk, groin, upper legs, and knees -- 44. Spleen injuries in athletes -- 45. Rib injuries -- 46.

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Groin pulls -- 47. Testicular injuries -- 48. Injuries to the hips -- section 48.1. Hip bursitis -section 48.2. Hip flexor strains -section 48.3. Quadriceps contusions and hip pointers -- 49. Injuries affecting the upper leg -section 49.1. Compartment syndrome -- section 49.2. Hamstring strain -- section 49.3. Femur fracture -- section 49.4. Quadriceps tendon rupture -- 50. Questions and answers about knee problems -- 51. OsgoodSchlatter disease: a common cause of knee pain in children -52. Anterior cruciate ligament (ACL) and other knee ligament injuries -- section 52.1. Knee ligament injuries -- section 52.2. The injured ACL -- section 52.3. ACL injuries in skeletally immature athletes -- section 52.4. Knee injuries and the female athlete -- 53. Injuries to the patella and the patellar tendon -section 53.1. Patellar tendon ruptures -- section 53.2. Patellar tendonitis (jumper's knee) -section 53.3. Dislocated patella -54. Knee cartilage injuries -section 54.1. Chondromalacia patella (runner's knee) -- section 54.2. Meniscal injuries -- section 54.3. Osteochondritis dissecans -55. Bursitis of the knee -- 56. Iliotibial band syndrome -- pt. VIII. Injuries to the lower legs, ankles, and feet -- 57. Shin splints

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Bibliography -- 58. Achilles tendon injuries: tendonitis and tears -- 59. Injuries to the ankles -- section 59.1. Ankle sprain -- section 59.2. Ankle fracture -- section 59.3. Osteochondritis dissecans-talus -60. Foot conditions -- section 60.1. Plantar fasciitis -- section 60.2. Sever disease -- section 60.3. Sesamoiditis -- 61. Toe injuries -- section 61.1. Turf toe - section 61.2. Toe sprains -section 61.3. Toe and forefoot fractures -- pt. IX. Diagnostic techniques, treatment methods, and rehabilitation -- 62. Diagnosing sports injuries -section 62.1. Orthopaedic imaging techniques -- section 62.2. Magnetic resonance imaging and ultrasound -- section 62.3. Arthroscopy -- 63. Commonly prescribed medications for sports injuries -64. Corticosteroid and nerveblocking injections -- 65. Specialized surgical treatment techniques -- section 65.1. Arthroscopic surgery -- section 65.2. Cartilage transfer -- section 65.3. Meniscal repair -- section 65.4. Thermal surgery -- section 65.5. Extracorporeal shock wave therapy -- 66. Functional exercise in rehabilitation of injured athletes -- 67. Return to play -pt. X. Additional help and information -- 68. Glossary of terms related to sports injuries --

69. Sports injuries resource list. Subjects: Sports injuries. Sports medicine. Wounds and injuries. Notes: Includes bibliographical references and index. Series: Health reference series Health reference series (Unnumbered) LCCN: 2007011758 The Achilles tendon; treatment and rehabilitation LCCN: 2008930711 The Achilles tendon; treatment and rehabilitation / edited by James A. Nunley. Published/Created: New York, NY; Springer, c2009. Description: xv, 255 p.; ill.; 26 cm. ISBN: 9780387792057 (hbk.; alk. paper) 0387792058 (hbk.; alk. paper) 0387792066 (ebk.) 9780387792064 (ebk.) LC classification: RD593 .A25 2009 Related names: Nunley, James A. Subjects: Achilles tendon-Wounds and injuries. Sports injuries. Achilles Tendon-injuries. Rupture--rehabilitation. Tendinopathy--rehabilitation. Tendon calcanéen--traumatismes. Rupture--rééducation et réadaptation. Tendinopathie-rééducation et réadaptation. Tendon d'Achille--Lésions et blessures. Notes: Includes bibliographical references and index.

INDEX # 3D finite element model, 81

aseptic, 83 assessment, viii, 2, 6, 17, 22, 38, 89 asthma, 91 athletes, 3, 7, 11, 12, 36, 91 atrophy, 72

A acetylcholine, 33 Achilles tendinopathy, vii, viii, 1, 2, 3, 4, 5, 12, 14, 15, 22, 30, 33, 35, 36, 37, 38 Achilles tendon, vii, viii, ix, 2, 3, 4, 5, 8, 10, 15, 25, 31, 36, 37, 39, 40, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 89, 94 ACL, 93 acupuncture, viii, 2, 4, 6, 30, 32, 34 acupuncture and iontophoresis, 32 adhesive capsulitis, 92 Africa, 74 Alfredson, 8, 9, 22, 23, 26, 27, 31, 36, 38 Alfredson and Stanish, 31 anatomy, 73, 74, 78, 85 ankles, 82, 91 ankylosing spondylitis, 3 ANOVA, 25, 27 anti-inflammatory drugs, viii, 2, 4 ARs, 83 arthritis, 86, 87, 89, 91 arthrodesis, 85 arthroplasty, 87 articular cartilage, 86 articulation, 77, 78, 82, 84

B back pain, 93 benefits, 68, 73, 91 bilateral, 5, 7, 20, 26 biomechanical characteristics, vii, ix, 77 biomechanics, 78, 84 bipedal, ix, 65, 67, 68, 69, 70, 71 blood, 3, 20, 72 blood flow, 20, 72 blood supply, 3 body weight, 66, 72, 78, 82 bones, 40, 44, 66, 77, 78, 80, 81, 83, 84, 93 braces, 6, 31 brain, 68 bursitis, 93

C cardiac arrest, 91 carnivorous diet, 67 cartilage, 78, 80, 81, 93 catecholamines, 33 challenges, 86 children, 93 chimpanzee, 69

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Index

classification, 89, 90, 91, 94 clinical application, 85 clinical diagnosis, 4 clinical trials, viii, 2, 5, 6, 30 collagen, 4, 32, 33, 46, 66, 67, 70, 72, 73 complement, 12, 32 compliance, 12, 40 complications, 84 congruence, 78 consensus, 5, 6 contour, 80 control group, 9, 17, 20, 21, 24, 27 controlled trials, viii, 2, 5 cooling, 75 correlation, 14, 15 correlation coefficient, 14 cost, 67 crepitus, 20 cycling, 43 Cyriax, viii, 2, 4, 6, 27, 30, 32, 34 Cyriax massages, 32 Cyriax treatment, 30

D daily living, 8 database, 5 deformation, 53, 61 deltoid, 78 detectable, 3 diet, 67 discomfort, 78 dislocation, 92 displacement, 45, 50, 52, 62 distribution, 80, 86 diversity, 30 doctors, 65 DOI, 37 doppler, 22 dorsiflexion, vii, 1, 3, 10, 11, 20, 52, 56, 82

E eccentric exercise, viii, 2, 4, 5, 8, 10, 11, 15, 16, 17, 18, 21, 23, 24, 25, 27, 28, 30, 34, 35, 36, 63 eccentric exercises, viii, 2, 4, 5, 11, 15, 17, 18, 21, 23, 27, 30, 34, 35, 36 eccentric exercises (different program), 30 elastic energy, vii, viii, 39, 40, 42, 49, 61, 69, 70 elastin, 66 elbows, 91 elongation, 42, 43, 45, 46, 47, 50, 58, 59 emergency, 91 EMG, 63 endurance, ix, 63, 65, 69 energy, vii, viii, ix, 3, 39, 40, 42, 49, 59, 60, 61, 63, 65, 67, 69, 70, 71 energy expenditure, ix, 65, 69 entrapment, 93 environments, 75 equipment, 91 ethics, 38 etiology, vii, 1, 3 evidence, 4, 13, 32 evolution, vii, 1, 3, 4, 7, 38, 65, 66, 74 exercise, 8, 9, 10, 12, 13, 14, 15, 16, 17, 18, 20, 21, 22, 23, 24, 25, 26, 27, 28, 30, 31, 35, 36, 38, 42, 43, 61, 63, 67, 71, 72, 73, 91 exercise program, 8, 15, 16, 17, 18, 21, 23, 25, 27, 28, 36 exercise programs, 8 exercises, viii, 2, 4, 5, 8, 10, 11, 15, 17, 18, 20, 21, 22, 23, 26, 27, 28, 30, 34, 35, 36 extensor, 86 external validation, 33

F factor analysis, 9 fascia, 79 fiber, 3, 41, 46 fibroblasts, 32

97

Index fibula, 78 finite element method, 80 first generation, 83, 84 flaws, 66 flexibility, 11, 66 flexor, 59, 70, 86, 93 food, 67, 68 football, 92 Football, 92 force, vii, viii, 11, 39, 40, 41, 42, 45, 46, 47, 50, 54, 58, 59, 63, 67, 69, 70, 72, 79, 80, 82 force-generating capability, vii, viii, 39, 40, 42 fractures, 84, 91 friction, vii, 1, 3

G gait, 78, 80, 81, 85 gastrocnemius, 41, 42, 43, 55, 58, 59, 60, 61, 62, 66, 70, 71 glutamate, 33 gravity, 68, 79 growth, 91

H hardness, 18 head injuries, 91 healing, 3, 30, 72 health, 8, 13, 26, 91 health information, 91 health status, 8 heat exhaustion, 68 heat loss, 67, 75 Heglund disease, vii, 1, 3 height, 81 heterogeneity, 30, 33 hip joint, 78 hives, 91 human body, ix, 2, 45, 77 human brain, 68 human movements, 40, 42, 47, 60

hunting, ix, 65, 67, 68 hypertrophy, 3, 62, 63 hyponatremia, 91 hysteresis, 69

I images, 44, 47, 53, 54, 55 imaging modalities, viii, 39 implants, 84 improvements, 19, 25 impulses, 24 in vivo, 45, 59, 60, 62, 63 independence, 66 individual differences, 45 infection, 84 inflammation, 8, 18, 20, 25, 30, 32, 33, 34 inflammatory disease, 5 inflammatory responses, 63 injections, viii, 2, 4, 94 injury, ix, 3, 65, 71, 72, 73, 74, 91, 94 injury prevention, 91 insertion, 3, 11, 31, 49, 54 integration, 31 Intense pulsed light, 19, 32, 37 internal validity, 5 intervention, viii, 2, 6, 11, 13, 14, 38 iontophoresis, viii, 2, 4, 6, 24, 25, 30, 34 Iontophoresis, 32, 37 iontophoresis and acupuncture, 34 iontophoresis and splints / orthotics, 30 isolation, viii, 2, 32, 33

J joints, ix, 77, 78, 79, 86 jumping, 14, 22, 49, 54, 62

K knee extension, vii, 1, 3, 23 knees, 68, 91

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Index

L laser, vii, 2, 4, 6, 15, 17, 30, 35, 36, 37 lateral epicondylitis, 92 lead, ix, 40, 43, 72, 73, 91 legs, 18, 66, 69, 72, 93 ligament, 68, 78, 82, 84, 93 Likert scale, 21 low frequency laser, 32 low risk, 5

M magnetic resonance imaging (MRI), viii, 39, 40, 45, 47, 49, 54, 63, 81 magnitude, 40, 42, 43, 45, 46, 52, 57, 58, 78, 80, 85 massage, viii, 2, 4, 27 massage of Cyriax, viii, 2 materials, 60, 86 measurement, viii, 8, 17, 36, 39, 45, 47, 49, 51, 52, 54, 58, 59, 62 measurements, 13, 32, 59 mechanical properties, 64 medial epicondylitis, 92 median, 21 medicine, 94 meta-analysis, 37 metabolism, 62 methodology, 30 microdialysis, 36 migration, 84 models, 57, 70, 84 modulus, 46, 47, 70, 80, 81 morning stiffness, 16 MTS, 82 muscle contraction, viii, 39, 50, 53, 58 muscle mass, 69 muscles, 2, 40, 55, 66, 68, 69, 71, 79, 86 muscle-tendon complex, vii, viii, 39, 40, 42, 43, 49, 51, 52, 54, 56

N neovascularization, 16, 33 nerve, 93 neuropeptides, 33 North America, 89 NRS, 8, 21 nuclear magnetic resonance (NMR), 4 numerical analysis, 80 nutrition, 91

O orthopedic braces, 6, 30 ortostatic measure, vii, 2, 4 ortostatic measures, vii, 2, 4 oscillation, 40 overtraining, 91 oxygen, 69, 72 oxygen consumption, 69

P pain, 2, 3, 4, 8, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 23, 25, 26, 28, 30, 31, 33, 34, 36, 37, 77, 89, 93 palpation, 3, 8, 11, 20 participants, 7, 9, 15 patella, 93 patellar tendon, 93 pathology, 31, 33, 34, 78, 85 pathophysiology, 33 Philadelphia, 85, 89 physical activity, 18, 31 physical therapies, vii, viii, 2, 4, 31, 34 physical therapist, viii, 39 physical therapy, 2, 4, 5, 30, 34, 40 pilot study, 36 placebo, 15, 17, 21, 32, 36 plantar flexion, 3, 52, 56, 61, 82 platform, 6, 11, 30, 34 PMMA, 84 population, 8, 38 potential benefits, 15

Index practice guides, 4 predators, 68 preparedness, 91 prevention, 91 primates, ix, 65, 67, 69 probability, 22, 73 probe, 52, 53, 55, 62 prostaglandin, 36 prostheses, 83, 84 prosthesis, 78, 86 protection, 91 prototype, 84 psoriasis, 3 pulsed light, viii, 2, 4, 6, 19, 30, 37

Q quadriceps, 69

R race, 69 radius, 83 rating scale, 8 recovery, 8, 14, 20, 21 recovery process, 20 recreational, 11, 36 regeneration, 19, 30, 32 rehabilitation, viii, 2, 4, 8, 36, 91, 93, 94 relaxation, 52, 54 repair, 72, 94 repetitions, 9, 10, 15, 21, 22, 23, 26, 27, 28 resistance, 11 resources, 91 respiration, 68 risk, 33, 68, 73 risks, 91

S safety, 92 SAS, 13, 24 scar tissue, 3 second generation, 83, 84

99

sedentary lifestyle, 72, 73 sensitivity, 85 sensor, 82 shape, 46, 50, 52, 53, 56, 57, 83, 84 shear, 70, 82 sheep, 61 shock, vii, 2, 4, 5, 24, 30, 34, 43, 94 shock wave, vii, 2, 4, 5, 24, 30, 34, 94 shockwaves techniques, 32 showing, 70 significance level, 23 simulations, 82 skeletal muscle, 63, 64 skeleton, 79 skin, 32, 45, 53, 67, 68, 89, 91 soccer, 92 social activities, 11 software, 13, 16, 20 soleus, 55, 61, 66, 71 South Africa, 74 Spain, 1 spine, 93 spine fractures, 93 splint, 10, 12, 13, 16, 31, 35 splint Airheel, 31 splinting, 35 splints, 6, 24, 30, 31, 94 splints/braces, 31 splints/orthopedic braces, 30 spondylolisthesis, 93 sprains, 89, 91, 92 SPSS software, 19 stability, 78, 80, 83, 84, 85 stabilization, 87 standard deviation, 14 standardization, 33 Stanish, 8, 23, 27, 31, 38 stars, 33 storage, 63, 70 stress, 46, 47, 68, 70, 80, 81, 82, 85, 91 stretches, 5, 22, 31 stretching, 6, 17, 18, 23, 24, 25, 27, 30, 34, 36, 62 structure, ix, 11, 31, 65, 70, 71, 73, 77, 78, 85

100

Index

subacute, 33 surface area, 78 surgical technique, 87 swelling, 18, 25 symptoms, 3, 8, 14, 26 synthesis, 67

T target population, 38 team members, 6 techniques, viii, 2, 4, 5, 8, 10, 11, 13, 30, 33, 92 technology, 45 teeth, 92 tendinitis, vii, viii, 1, 2, 3, 4, 18, 20, 22, 30, 31, 33, 36, 37, 38 tendon, vii, viii, ix, 2, 3, 4, 5, 8, 10, 11, 12, 13, 14, 15, 18, 19, 20, 22, 25, 26, 27, 30, 31, 33, 34, 36, 37, 38, 39, 40, 41, 42, 43, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 89, 92, 94 tendons, viii, 2, 8, 14, 16, 20, 39, 40, 42, 45, 46, 66, 69, 70 tennis elbow, 92 tensile strength, 66, 70, 72, 78 tension, 59, 60, 64 therapeutic effect, 35 therapy, vii, 2, 4, 6, 11, 13, 15, 24, 30, 31, 35, 36, 89, 90, 94 tibia, 3, 78, 84 tibialis anterior, 45 time resolution, 47, 49, 54 tissue, 3, 81, 82 total ankle replacement, vii, ix, 77, 78, 84, 85, 86 total energy, 70 toxin, 92 training, 11, 13, 14, 31, 35, 36, 37, 38, 62, 73, 92 training programs, 31 translation, 34

trauma, vii, 1, 3, 71 treatment, vii, viii, 2, 4, 5, 6, 8, 9, 10, 11, 13, 15, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 30, 33, 35, 36, 37, 38, 78, 91, 94 treatment methods, 94 trial, 6, 30, 35, 36 triceps, 20, 23, 53, 54, 55, 56, 62, 63

U ultrasonography, viii, 4, 8, 19, 39, 40, 45, 47, 49, 50, 51, 61 ultrasound, 2, 4, 5, 11, 16, 19, 26, 30, 32, 36, 60, 62, 94 urticaria, 91 US vibrating laser platform, 32

V valgus, 89 varus, 3 vascularization, 3, 22 vessels, 16 vibrating platform, 6, 11 vibration, 11, 30, 34, 37 vibration isolation platform, 32 vibration platform, 30, 34 Vibration therapy, 11, 30 viscoelastic properties, 62 vulnerability, ix, 65, 71

W walking, 42, 43, 49, 60, 61, 62, 67, 71, 72, 74, 89 wallabies, 59 water, 66, 67, 68 wear, 83, 84 wound healing, 84 wrists, 92