Journal of Orthopaedic & Sports Physical Therapy® Downloaded from www.jospt.org at University of Pittsburgh on June 2, 2014. For personal use only. No other uses without permission. Copyright © 2014 Journal of Orthopaedic & Sports Physical Therapy®. All rights reserved.
[
editorial
]
Does One Size Fit All When It Comes to Exercise Treatment for Achilles Tendinopathy? KARIN GRÄVARE SILBERNAGEL, PT, PhD, ATC Associate Editor J Orthop Sports Phys Ther 2014;44(2):42-44. doi:10.2519/jospt.2014.0103
C
linical studies have repeatedly shown that exercise is crucial in musculoskeletal rehabilitation. Our bodies need to be chal lenged to respond with improved strength and function. At the cellular level, studies indicate that mechanical loading helps maintain healthy muscle, bone, and tendon tissue. An important aspect of physical therapy is the prescription and implementation of exercise. The goals of exercise include improvement of impairments and disabilities identified during clinical evaluation. However, exercise as treatment can also be used to promote tissue adaptation and healing after injury. Mechanotransduction refers to the continuum of processes in which cells convert mechanical stimulus into cellular responses that promote structural changes.10 Tendinopathy provides a pertinent example of how changes in prescribed exercise treatment have resulted in improved clinical and functional outcomes. Historically, painful tendon injuries were called tendinitis and assumed to be an inflammatory condition.9 Most patients were therefore recommended to discontinue the activity that caused pain, and loading of the injured tendon was minimized to provide additional rest. Then, in the late 1990s, the condition was shown not to be inflammatory but a degenerative change in tendon, such as tendinosis.3 Overload-
ing of the tendon, without enough time for recovery, causes this type of injury, but underloading of the tendon has also been shown to be detrimental.17 Today, we know that mechanical loading of injured tendons is of major importance to promote healing, and also for maintaining healthy tendon tissue.12,13 The authors of systematic reviews performed in the late 2000s have concluded that heavy, painful eccentric exercises had the greatest evidence of effectiveness in athletic patients with Achilles tendinopathy.11,18 However, this approach has been shown to be less effective in nonathletic and older patients.6,21 The most widely recommended exercise protocol is the Alfredson protocol,1 which consists of eccentric exercise, performed twice a day, every day, for 12 weeks. This recommended approach conflicts with other studies that have found that tendon needs 72 hours to achieve a net collagen synthesis after heavy loading.16
Therefore, the above widely accepted protocol might provide an inappropriate dosage of mechanical stimulus for older and nonathletic patients, and therefore might not result in positive treatment outcomes. For tendons at the elbow and shoulder, this treatment protocol has also been less successful, and this might also be due to using less than optimal exercise dosage.7,23 Furthermore, it is not known if the tendon actually responds differently to eccentric compared to concentric loading, and there are indications that as long as the tendon is loaded, the type of muscle contraction might not matter.20 It could be that other combinations of exercise frequency, duration, and type of muscle contraction may be of similar or even greater benefit. Animal studies indicate that the specifics of exercise are of great importance, both for promoting faster tendon healing and return of function and for avoiding long-term or even permanent deficits.2,5 Tendons increase their tensile strength, stiffness, and total weight with exercise, and the injured tendon requires mechanical loading in all phases of healing to recover.8,12 There is also indication that tendinopathic and healthy tendons respond differently to eccentric exercise.15 An animal study found that treadmill en-
42 | february 2014 | volume 44 | number 2 | journal of orthopaedic & sports physical therapy
44-02 Editorial.indd 42
1/17/2014 4:57:11 PM
Journal of Orthopaedic & Sports Physical Therapy® Downloaded from www.jospt.org at University of Pittsburgh on June 2, 2014. For personal use only. No other uses without permission. Copyright © 2014 Journal of Orthopaedic & Sports Physical Therapy®. All rights reserved.
durance training changed the mechanical properties of the Achilles tendon but did not cause tendon hypertrophy,4 suggesting that the Achilles tendon may respond to repeated stress by improving its capacity to withstand mechanical fatigue but not necessarily higher loads. Even studies on the cellular level indicate that tendon stem-cell proliferation with mechanical loading is magnitude dependent.24 In summary, clinical, animal, and cellular studies all suggest that the type and dosage of exercise are important for achieving optimal recovery and function of tendon tissue. Despite this, clinically, there is a tendency to apply the principle that one size fits all when it comes to exercise as treatment of injured tendon tissues. The importance of the dosage of mechanical loading, as treatment for Achilles and patellar tendinopathy, was addressed in a recent systematic review by Malliaras et al.19 The authors concluded that there is a paucity of evidence comparing various loading programs and that the current simplistic approach of the eccentric training program should be questioned. Only 1 study,14 performed in individuals with patellar tendinopathy, had compared the twice-daily eccentric exercise protocol with a heavy strengthening program performed 3 times a week. This study14 found that both groups improved in symptoms, but the heavy strengthening program had superior results in tendon recovery. This month’s issue of JOSPT includes a paper by Marc Stevens and Dr CheeWee Tan22 that questions this notion of having a one-size-fits-all eccentric exercise treatment protocol for patients with Achilles tendinopathy. This study22 compares the eccentric-only protocol that requires the patients to perform 180 repetitions per day with, as they call it, a “do-as-tolerated” exercise protocol. Both groups performed exactly the same exercise, the eccentric heel drop, but the do-as-tolerated group was told that they could choose to complete as many repetitions as they could tolerate. After 6 weeks
of treatment, both groups had significant improvement, with no significant difference between the groups in the amount of change. Despite this study22 only using a short follow-up (6 weeks), the results suggest that the dosage can be changed and a positive response can still be achieved. Although one has to be somewhat cautious when interpreting the results of this study,22 because no functional outcome measures or evaluation of tendon structure or mechanical properties were performed, this study provides support for further research into understanding the effect of dosage of exercise on outcome. The results have a direct impact on the clinical application of this treatment protocol, as they indicate that it may not be necessary to push the patients to perform more repetitions than they perceive tolerable. We all know that having patients be comfortable with their treatment protocol helps with compliance. In summary, we still have more questions than answers concerning the appropriate dose of exercise for tendinopathy. I would argue, however, that it is crucial for us as physical therapists to pursue these research questions so that we can better individualize the exercise treatment protocols. There is a tendency, especially with Achilles tendinopathy, to quickly dismiss exercise as treatment, just because a patient does not quickly respond to the onesize-fits-all program, and instead pursue other more costly and invasive treatment options. However, all the evidence points toward exercise and mechanical loading as the most potent “medication,” superior to other interventions such as low-level laser, extracorporeal shockwave therapy, nitric oxide, injection therapies, and surgery for the treatment of tendinopathy. With drugs, we would not just arbitrarily give every patient the same dosage, then dismiss the medication as useless if not everybody has the same response. Similar reasoning is needed when considering dosage of exercise. Physical therapists, as the movement and exercise experts, need to pursue research on defining the optimal exercise
dosage to treat all of their patients, not just athletes, with Achilles tendinopathy. Future research that evaluates the specifics of exercise dosage, such as the study performed by Marc Stevens and Dr Chee-Wee Tan,22 is needed to enhance our understanding of using exercise as an effective treatment for tendon injuries. t
REFERENCES 1. A lfredson 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;26:360-366. 2. Aspenberg P. Stimulation of tendon repair: mechanical loading, GDFs and platelets. A minireview. Int Orthop. 2007;31:783-789. http://dx.doi. org/10.1007/s00264-007-0398-6 3. Åström M, Rausing A. Chronic Achilles tendinopathy. A survey of surgical and histopathologic findings. Clin Orthop Relat Res. 1995:151-164. 4. Buchanan CI, Marsh RL. Effects of long-term exercise on the biomechanical properties of the Achilles tendon of guinea fowl. J Appl Physiol (1985). 2001;90:164-171. 5. Enwemeka CS. Functional loading augments the initial tensile strength and energy absorption capacity of regenerating rabbit Achilles tendons. Am J Phys Med Rehabil. 1992;71:31-38. 6. Johnston E, Scranton P, Jr., Pfeffer GB. Chronic disorders of the Achilles tendon: results of conservative and surgical treatments. Foot Ankle Int. 1997;18:570-574. 7. Jonsson P, Wahlström P, Öhberg L, Alfredson H. Eccentric training in chronic painful impingement syndrome of the shoulder: results of a pilot study. Knee Surg Sports Traumatol Arthrosc. 2006;14:76-81. http://dx.doi.org/10.1007/ s00167-004-0611-8 8. Kannus P, Józsa L, Natri A, Järvinen M. Effects of training, immobilization and remobilization on tendons. Scand J Med Sci Sports. 1997;7:67-71. 9. Khan KM, Cook JL, Kannus P, Maffulli N, Bonar SF. Time to abandon the “tendinitis” myth. BMJ. 2002;324:626-627. 10. Khan KM, Scott A. Mechanotherapy: how physical therapists’ prescription of exercise promotes tissue repair. Br J Sports Med. 2009;43:247-252. http://dx.doi.org/10.1136/bjsm.2008.054239 11. Kingma JJ, de Knikker R, Wittink HM, Takken T. Eccentric overload training in patients with chronic Achilles tendinopathy: a systematic review. Br J Sports Med. 2007;41:e3. http://dx.doi. org/10.1136/bjsm.2006.030916 12. Kjaer M. Role of extracellular matrix in adaptation of tendon and skeletal muscle to mechanical loading. Physiol Rev. 2004;84:649-698. http:// dx.doi.org/10.1152/physrev.00031.2003 13. Kjaer M, Langberg H, Miller BF, et al. Metabolic activity and collagen turnover in human tendon
journal of orthopaedic & sports physical therapy | volume 44 | number 2 | february 2014 |
44-02 Editorial.indd 43
43
1/17/2014 4:57:12 PM
[ 14.
Journal of Orthopaedic & Sports Physical Therapy® Downloaded from www.jospt.org at University of Pittsburgh on June 2, 2014. For personal use only. No other uses without permission. Copyright © 2014 Journal of Orthopaedic & Sports Physical Therapy®. All rights reserved.
15.
16.
17.
in response to physical activity. J Musculoskelet Neuronal Interact. 2005;5:41-52. Kongsgaard M, Kovanen V, Aagaard P, et al. Corticosteroid injections, eccentric decline squat training and heavy slow resistance training in patellar tendinopathy. Scand J Med Sci Sports. 2009;19:790-802. http://dx.doi. org/10.1111/j.1600-0838.2009.00949.x Langberg H, Ellingsgaard H, Madsen T, et al. Eccentric rehabilitation exercise increases peritendinous type I collagen synthesis in humans with Achilles tendinosis. Scand J Med Sci Sports. 2007;17:61-66. http://dx.doi. org/10.1111/j.1600-0838.2006.00522.x Langberg H, Skovgaard D, Asp S, Kjaer M. Time pattern of exercise-induced changes in type I collagen turnover after prolonged endurance exercise in humans. Calcif Tissue Int. 2000;67:4144. http://dx.doi.org/10.1007/s00223001094 Leadbetter WB. Cell-matrix response in tendon
editorial
]
injury. Clin Sports Med. 1992;11:533-578. 18. M agnussen RA, Dunn WR, Thomson AB. Nonoperative treatment of midportion Achilles tendinopathy: a systematic review. Clin J Sport Med. 2009;19:54-64. http://dx.doi.org/10.1097/ JSM.0b013e31818ef090 19. 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;43:267-286. http://dx.doi.org/10.1007/s40279-013-0019-z 20. Rees JD, Lichtwark GA, Wolman RL, Wilson AM. The mechanism for efficacy of eccentric loading in Achilles tendon injury; an in vivo study in humans. Rheumatology (Oxford). 2008;47:14931497. http://dx.doi.org/10.1093/rheumatology/ ken262 21. Sayana MK, Maffulli N. Eccentric calf muscle training in non-athletic patients with Achilles
tendinopathy. J Sci Med Sport. 2007;10:52-58. http://dx.doi.org/10.1016/j.jsams.2006.05.008 22. Stevens M, Tan CW. Effectiveness of the Alfredson protocol compared with a lower repetitionvolume protocol for mid-portion Achilles tendinopathy: a randomized controlled trial. J Orthop Sports Phys Ther. 2014;44:45-57. http://dx.doi. org/10.2519/jospt.2014.4720 23. Woodley BL, Newsham-West RJ, Baxter GD. Chronic tendinopathy: effectiveness of eccentric exercise. Br J Sports Med. 2007;41:188-198; discussion 199. http://dx.doi.org/10.1136/ bjsm.2006.029769 24. Zhang J, Wang JH. Mechanobiological response of tendon stem cells: implications of tendon homeostasis and pathogenesis of tendinopathy. J Orthop Res. 2010;28:639-643. http://dx.doi. org/10.1002/jor.21046
GO GREEN By Opting Out of the Print Journal JOSPT subscribers and APTA members of the Orthopaedic and Sports Physical Therapy Sections can help the environment by “opting out” of receiving JOSPT in print each month as follows. If you are: • A JOSPT subscriber: Email your request to [email protected] or call the JOSPT office toll-free at 1-877-766-3450 and provide your name and subscriber number. • APTA Orthopaedic or Sports Section member: Go to http://www.apta.org/, log in, and select My Profile. Next click on Email Management/GoGreen. Toward the bottom of the list, you will find the Publications options and may opt out of receiving the print JOSPT. Please save this preference. Subscribers and members alike will continue to have access to JOSPT online and can retrieve current and archived issues anytime and anywhere you have Internet access.
44 | february 2014 | volume 44 | number 2 | journal of orthopaedic & sports physical therapy
44-02 Editorial.indd 44
1/17/2014 4:57:13 PM
[
editorial
]
Does One Size Fit All When It Comes to Exercise Treatment for Achilles Tendinopathy? KARIN GRÄVARE SILBERNAGEL, PT, PhD, ATC Associate Editor J Orthop Sports Phys Ther 2014;44(2):42-44. doi:10.2519/jospt.2014.0103
C
linical studies have repeatedly shown that exercise is crucial in musculoskeletal rehabilitation. Our bodies need to be chal lenged to respond with improved strength and function. At the cellular level, studies indicate that mechanical loading helps maintain healthy muscle, bone, and tendon tissue. An important aspect of physical therapy is the prescription and implementation of exercise. The goals of exercise include improvement of impairments and disabilities identified during clinical evaluation. However, exercise as treatment can also be used to promote tissue adaptation and healing after injury. Mechanotransduction refers to the continuum of processes in which cells convert mechanical stimulus into cellular responses that promote structural changes.10 Tendinopathy provides a pertinent example of how changes in prescribed exercise treatment have resulted in improved clinical and functional outcomes. Historically, painful tendon injuries were called tendinitis and assumed to be an inflammatory condition.9 Most patients were therefore recommended to discontinue the activity that caused pain, and loading of the injured tendon was minimized to provide additional rest. Then, in the late 1990s, the condition was shown not to be inflammatory but a degenerative change in tendon, such as tendinosis.3 Overload-
ing of the tendon, without enough time for recovery, causes this type of injury, but underloading of the tendon has also been shown to be detrimental.17 Today, we know that mechanical loading of injured tendons is of major importance to promote healing, and also for maintaining healthy tendon tissue.12,13 The authors of systematic reviews performed in the late 2000s have concluded that heavy, painful eccentric exercises had the greatest evidence of effectiveness in athletic patients with Achilles tendinopathy.11,18 However, this approach has been shown to be less effective in nonathletic and older patients.6,21 The most widely recommended exercise protocol is the Alfredson protocol,1 which consists of eccentric exercise, performed twice a day, every day, for 12 weeks. This recommended approach conflicts with other studies that have found that tendon needs 72 hours to achieve a net collagen synthesis after heavy loading.16
Therefore, the above widely accepted protocol might provide an inappropriate dosage of mechanical stimulus for older and nonathletic patients, and therefore might not result in positive treatment outcomes. For tendons at the elbow and shoulder, this treatment protocol has also been less successful, and this might also be due to using less than optimal exercise dosage.7,23 Furthermore, it is not known if the tendon actually responds differently to eccentric compared to concentric loading, and there are indications that as long as the tendon is loaded, the type of muscle contraction might not matter.20 It could be that other combinations of exercise frequency, duration, and type of muscle contraction may be of similar or even greater benefit. Animal studies indicate that the specifics of exercise are of great importance, both for promoting faster tendon healing and return of function and for avoiding long-term or even permanent deficits.2,5 Tendons increase their tensile strength, stiffness, and total weight with exercise, and the injured tendon requires mechanical loading in all phases of healing to recover.8,12 There is also indication that tendinopathic and healthy tendons respond differently to eccentric exercise.15 An animal study found that treadmill en-
42 | february 2014 | volume 44 | number 2 | journal of orthopaedic & sports physical therapy
44-02 Editorial.indd 42
1/17/2014 4:57:11 PM
Journal of Orthopaedic & Sports Physical Therapy® Downloaded from www.jospt.org at University of Pittsburgh on June 2, 2014. For personal use only. No other uses without permission. Copyright © 2014 Journal of Orthopaedic & Sports Physical Therapy®. All rights reserved.
durance training changed the mechanical properties of the Achilles tendon but did not cause tendon hypertrophy,4 suggesting that the Achilles tendon may respond to repeated stress by improving its capacity to withstand mechanical fatigue but not necessarily higher loads. Even studies on the cellular level indicate that tendon stem-cell proliferation with mechanical loading is magnitude dependent.24 In summary, clinical, animal, and cellular studies all suggest that the type and dosage of exercise are important for achieving optimal recovery and function of tendon tissue. Despite this, clinically, there is a tendency to apply the principle that one size fits all when it comes to exercise as treatment of injured tendon tissues. The importance of the dosage of mechanical loading, as treatment for Achilles and patellar tendinopathy, was addressed in a recent systematic review by Malliaras et al.19 The authors concluded that there is a paucity of evidence comparing various loading programs and that the current simplistic approach of the eccentric training program should be questioned. Only 1 study,14 performed in individuals with patellar tendinopathy, had compared the twice-daily eccentric exercise protocol with a heavy strengthening program performed 3 times a week. This study14 found that both groups improved in symptoms, but the heavy strengthening program had superior results in tendon recovery. This month’s issue of JOSPT includes a paper by Marc Stevens and Dr CheeWee Tan22 that questions this notion of having a one-size-fits-all eccentric exercise treatment protocol for patients with Achilles tendinopathy. This study22 compares the eccentric-only protocol that requires the patients to perform 180 repetitions per day with, as they call it, a “do-as-tolerated” exercise protocol. Both groups performed exactly the same exercise, the eccentric heel drop, but the do-as-tolerated group was told that they could choose to complete as many repetitions as they could tolerate. After 6 weeks
of treatment, both groups had significant improvement, with no significant difference between the groups in the amount of change. Despite this study22 only using a short follow-up (6 weeks), the results suggest that the dosage can be changed and a positive response can still be achieved. Although one has to be somewhat cautious when interpreting the results of this study,22 because no functional outcome measures or evaluation of tendon structure or mechanical properties were performed, this study provides support for further research into understanding the effect of dosage of exercise on outcome. The results have a direct impact on the clinical application of this treatment protocol, as they indicate that it may not be necessary to push the patients to perform more repetitions than they perceive tolerable. We all know that having patients be comfortable with their treatment protocol helps with compliance. In summary, we still have more questions than answers concerning the appropriate dose of exercise for tendinopathy. I would argue, however, that it is crucial for us as physical therapists to pursue these research questions so that we can better individualize the exercise treatment protocols. There is a tendency, especially with Achilles tendinopathy, to quickly dismiss exercise as treatment, just because a patient does not quickly respond to the onesize-fits-all program, and instead pursue other more costly and invasive treatment options. However, all the evidence points toward exercise and mechanical loading as the most potent “medication,” superior to other interventions such as low-level laser, extracorporeal shockwave therapy, nitric oxide, injection therapies, and surgery for the treatment of tendinopathy. With drugs, we would not just arbitrarily give every patient the same dosage, then dismiss the medication as useless if not everybody has the same response. Similar reasoning is needed when considering dosage of exercise. Physical therapists, as the movement and exercise experts, need to pursue research on defining the optimal exercise
dosage to treat all of their patients, not just athletes, with Achilles tendinopathy. Future research that evaluates the specifics of exercise dosage, such as the study performed by Marc Stevens and Dr Chee-Wee Tan,22 is needed to enhance our understanding of using exercise as an effective treatment for tendon injuries. t
REFERENCES 1. A lfredson 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;26:360-366. 2. Aspenberg P. Stimulation of tendon repair: mechanical loading, GDFs and platelets. A minireview. Int Orthop. 2007;31:783-789. http://dx.doi. org/10.1007/s00264-007-0398-6 3. Åström M, Rausing A. Chronic Achilles tendinopathy. A survey of surgical and histopathologic findings. Clin Orthop Relat Res. 1995:151-164. 4. Buchanan CI, Marsh RL. Effects of long-term exercise on the biomechanical properties of the Achilles tendon of guinea fowl. J Appl Physiol (1985). 2001;90:164-171. 5. Enwemeka CS. Functional loading augments the initial tensile strength and energy absorption capacity of regenerating rabbit Achilles tendons. Am J Phys Med Rehabil. 1992;71:31-38. 6. Johnston E, Scranton P, Jr., Pfeffer GB. Chronic disorders of the Achilles tendon: results of conservative and surgical treatments. Foot Ankle Int. 1997;18:570-574. 7. Jonsson P, Wahlström P, Öhberg L, Alfredson H. Eccentric training in chronic painful impingement syndrome of the shoulder: results of a pilot study. Knee Surg Sports Traumatol Arthrosc. 2006;14:76-81. http://dx.doi.org/10.1007/ s00167-004-0611-8 8. Kannus P, Józsa L, Natri A, Järvinen M. Effects of training, immobilization and remobilization on tendons. Scand J Med Sci Sports. 1997;7:67-71. 9. Khan KM, Cook JL, Kannus P, Maffulli N, Bonar SF. Time to abandon the “tendinitis” myth. BMJ. 2002;324:626-627. 10. Khan KM, Scott A. Mechanotherapy: how physical therapists’ prescription of exercise promotes tissue repair. Br J Sports Med. 2009;43:247-252. http://dx.doi.org/10.1136/bjsm.2008.054239 11. Kingma JJ, de Knikker R, Wittink HM, Takken T. Eccentric overload training in patients with chronic Achilles tendinopathy: a systematic review. Br J Sports Med. 2007;41:e3. http://dx.doi. org/10.1136/bjsm.2006.030916 12. Kjaer M. Role of extracellular matrix in adaptation of tendon and skeletal muscle to mechanical loading. Physiol Rev. 2004;84:649-698. http:// dx.doi.org/10.1152/physrev.00031.2003 13. Kjaer M, Langberg H, Miller BF, et al. Metabolic activity and collagen turnover in human tendon
journal of orthopaedic & sports physical therapy | volume 44 | number 2 | february 2014 |
44-02 Editorial.indd 43
43
1/17/2014 4:57:12 PM
[ 14.
Journal of Orthopaedic & Sports Physical Therapy® Downloaded from www.jospt.org at University of Pittsburgh on June 2, 2014. For personal use only. No other uses without permission. Copyright © 2014 Journal of Orthopaedic & Sports Physical Therapy®. All rights reserved.
15.
16.
17.
in response to physical activity. J Musculoskelet Neuronal Interact. 2005;5:41-52. Kongsgaard M, Kovanen V, Aagaard P, et al. Corticosteroid injections, eccentric decline squat training and heavy slow resistance training in patellar tendinopathy. Scand J Med Sci Sports. 2009;19:790-802. http://dx.doi. org/10.1111/j.1600-0838.2009.00949.x Langberg H, Ellingsgaard H, Madsen T, et al. Eccentric rehabilitation exercise increases peritendinous type I collagen synthesis in humans with Achilles tendinosis. Scand J Med Sci Sports. 2007;17:61-66. http://dx.doi. org/10.1111/j.1600-0838.2006.00522.x Langberg H, Skovgaard D, Asp S, Kjaer M. Time pattern of exercise-induced changes in type I collagen turnover after prolonged endurance exercise in humans. Calcif Tissue Int. 2000;67:4144. http://dx.doi.org/10.1007/s00223001094 Leadbetter WB. Cell-matrix response in tendon
editorial
]
injury. Clin Sports Med. 1992;11:533-578. 18. M agnussen RA, Dunn WR, Thomson AB. Nonoperative treatment of midportion Achilles tendinopathy: a systematic review. Clin J Sport Med. 2009;19:54-64. http://dx.doi.org/10.1097/ JSM.0b013e31818ef090 19. 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;43:267-286. http://dx.doi.org/10.1007/s40279-013-0019-z 20. Rees JD, Lichtwark GA, Wolman RL, Wilson AM. The mechanism for efficacy of eccentric loading in Achilles tendon injury; an in vivo study in humans. Rheumatology (Oxford). 2008;47:14931497. http://dx.doi.org/10.1093/rheumatology/ ken262 21. Sayana MK, Maffulli N. Eccentric calf muscle training in non-athletic patients with Achilles
tendinopathy. J Sci Med Sport. 2007;10:52-58. http://dx.doi.org/10.1016/j.jsams.2006.05.008 22. Stevens M, Tan CW. Effectiveness of the Alfredson protocol compared with a lower repetitionvolume protocol for mid-portion Achilles tendinopathy: a randomized controlled trial. J Orthop Sports Phys Ther. 2014;44:45-57. http://dx.doi. org/10.2519/jospt.2014.4720 23. Woodley BL, Newsham-West RJ, Baxter GD. Chronic tendinopathy: effectiveness of eccentric exercise. Br J Sports Med. 2007;41:188-198; discussion 199. http://dx.doi.org/10.1136/ bjsm.2006.029769 24. Zhang J, Wang JH. Mechanobiological response of tendon stem cells: implications of tendon homeostasis and pathogenesis of tendinopathy. J Orthop Res. 2010;28:639-643. http://dx.doi. org/10.1002/jor.21046
GO GREEN By Opting Out of the Print Journal JOSPT subscribers and APTA members of the Orthopaedic and Sports Physical Therapy Sections can help the environment by “opting out” of receiving JOSPT in print each month as follows. If you are: • A JOSPT subscriber: Email your request to [email protected] or call the JOSPT office toll-free at 1-877-766-3450 and provide your name and subscriber number. • APTA Orthopaedic or Sports Section member: Go to http://www.apta.org/, log in, and select My Profile. Next click on Email Management/GoGreen. Toward the bottom of the list, you will find the Publications options and may opt out of receiving the print JOSPT. Please save this preference. Subscribers and members alike will continue to have access to JOSPT online and can retrieve current and archived issues anytime and anywhere you have Internet access.
44 | february 2014 | volume 44 | number 2 | journal of orthopaedic & sports physical therapy
44-02 Editorial.indd 44
1/17/2014 4:57:13 PM
