Eccentric Training for the Treatment of Tendinopathies

A Practical Guide to Injection Therapy in Hand Tendinopathies: A Systematic Review of Randomized Controlled Trials

Hand tendinopathies represent a pathological condition associated with significant disability. However, due to this high heterogeneity of the treatments and their efficacy, there is still a lack of consensus on the infiltrative therapy of the hand. This systematic review aimed to investigate the efficacy of injection techniques in the treatment of pain related to the main hand tendinopathies. We searched online medical databases (PubMed, Pedro, Cochrane Library, Scopus, and WoS). Only RCTs published in the last 10 years (up to 5 August 2024), written in English, and related to infiltrative treatment in wrist and hand tendinopathies were evaluated. The risk of bias in RCTs was assessed with Version 2 of the Cochrane Risk of Bias tool for randomized trials (RoB 2). Out of 641 articles identified, 23 were included in the final synthesis: 14 RCTs on trigger finger, and 9 RCTs on de Quervain's tenosynovitis. The present systematic review showed that infiltrative therapy of trigger finger and de Quervain's tenosynovitis constitutes a fundamental element in the treatment of these pathological conditions, in terms of pain reduction and improvement in the functionality of the hand.

The Use of Free Weight Squats in Sports: A Narrative Review-Squatting Movements, Adaptation, and Sports Performance: Physiological

ABSTRACT

Stone, MH, Hornsby, G, Mizuguchi, S, Sato, K, Gahreman, D, Duca, M, Carroll, K, Ramsey, MW, Stone, ME, and Haff, GG. The use of free weight squats in sports: a narrative review-squatting movements, adaptation, and sports performance: physiological. J Strength Cond Res 38(8): 1494-1508, 2024-The squat and its variants can provide numerous benefits including positively affecting sports performance and injury prevention, injury severity reduction, and rehabilitation. The positive benefits of squat are likely the result of training-induced neural alterations and mechanical and morphological adaptations in tendons, skeletal muscles, and bones, resulting in increased tissue stiffness and cross-sectional area (CSA). Although direct evidence is lacking, structural adaptations can also be expected to occur in ligaments. These adaptations are thought to beneficially increase force transmission and mechanical resistance (e.g., resistance to mechanical strain) and reduce the likelihood and severity of injuries. Adaptations such as these, also likely play an important role in rehabilitation, particularly for injuries that require restricted use or immobilization of body parts and thus lead to a consequential reduction in the CSA and alterations in the mechanical properties of tendons, skeletal muscles, and ligaments. Both volume and particularly intensity (e.g., levels of loading used) of training seem to be important for the mechanical and morphological adaptations for at least skeletal muscles, tendons, and bones. Therefore, the training intensity and volume used for the squat and its variations should progressively become greater while adhering to the concept of periodization and recognized training principles.

Tendinopathic Plantaris but Normal Achilles Tendon Found in About One-Fifth of Patients Not Responding to Conservative Achilles Tendon Management - Results from a Prospective WALANT Surgical Case Series on 105 Tendons

Purpose

Midportion Achilles tendinopathy is a relatively common condition. This study aimed to investigate the presence of a normal Achilles tendon, but a tendinopathic plantaris tendon, in a large and consecutive prospective sample of patients referred to a specialised tendon clinic for midportion Achilles tendon pain not responding to non-surgical treatment.

Patients and Methods

A total of 105 consecutive tendons were operated on in 81 patients (62 males) suffering from painful midportion Achilles tendon pain. Clinical examination, ultrasound (US) and colour Doppler (CD) examination, and wide awake local anaesthetic no tourniquet (WALANT) surgery were performed in all patients.

Results

For 19/105 (18%) tendons from 14 patients, clinical examination suspected plantaris tendinopathy alone as there was a distinct tenderness on the medial side, but no thickening of the Achilles tendon. US examination followed by surgery confirmed the diagnosis.

Conclusion

Midportion Achilles tendon pain is not always related to Achilles tendinopathy since pain related to the plantaris tendon alone was found in almost every fifth patient. Consequently, there is an obvious need for proper examination to identify the pain source and establish a correct diagnosis before treatment.

Eccentric Muscle Actions Add Complexity to an Already Inconsistent Resistance Exercise Nomenclature

An eccentric muscle action (or contraction) is defined as active muscle lengthening against resistance, which occurs when the force generated by the muscle is smaller than the resistance placed upon it. Eccentric resistance exercise, which involves multiple sessions of repeated eccentric muscle actions, improves muscle strength and other health outcomes. In response to this evidence, new exercise technologies have been developed to permit feasible completion of eccentric muscle actions outside of the laboratory. Consequently, participation in eccentric resistance exercise is projected to increase in the future, and communications about eccentric resistance exercise are likely to reach a wide audience, including students in the classroom, athletes in the weightroom, patients who receive telehealth services,  and journalists who report on study findings. Previous research has documented inconsistencies in how resistance exercises are named, but the role of eccentric resistance exercises has not been considered. Here, we explain how eccentric resistance exercises add further complexity to an already inconsistent resistance exercise nomenclature. Specifically, action words in exercise names typically describe the movement that occurs in the concentric phase (e.g., "press", "raise", "curl", "pull", "row"). This naming bias likely stems from the fact that traditional resistance exercise equipment, such as free weights and weight stack machines, does not typically accommodate for greater eccentric than concentric strength and thus emphasizes the concentric over eccentric phase. This naming bias is likely to hinder communications about eccentric resistance exercise. Thus, we encourage researchers and practitioners to discuss ways in which resistance exercises can be named more clearly and consistently.

Eccentric Contraction Enhances Healing of the Bone-Tendon Interface After Rotator Cuff Repair in Mice

BACKGROUND

Various muscle contraction modalities have differing effects on the musculoskeletal system. To understand the magnitude of these effects, the authors investigated the effects of eccentric and concentric contractions on the bone-tendon interface after rotator cuff repair in mice.

HYPOTHESIS

Eccentric contraction promotes healing of the bone-tendon interface after rotator cuff repair in mice better than other muscle contraction patterns.

STUDY DESIGN

Controlled laboratory study.

METHODS

The authors performed acute supraspinatus tendon repair of the right shoulder in 104 C57BL/6 mice. Animals were randomized into 4 groups postoperatively: control group (Con group), horizontal running group (Horz group), +15° uphill running group (Up group), and -15° downhill running group (Down group), with 26 animals in each group. At 4 and 8 weeks postoperatively, the authors removed the eyeball, collected blood samples, and extracted the supraspinatus tendon-humerus complex for histological, immunological, bone morphological, and biomechanical tests.

RESULTS

At 4 and 8 weeks postoperatively, the Down group exhibited a better collagen cell arrangement and fibrocartilage layer than the other 3 groups. At 4 weeks postoperatively, anti-inflammatory macrophages (M2 macrophages) were observed at the repair site in all groups except for the Con group. At 8 weeks postoperatively, M2 macrophages were withdrawn from the tendon site in all groups. The transforming growth factor β1 concentration in the Down group was greater than that in the other 3 groups at 4 weeks postoperatively, and it was higher than that in the Con group at 8 weeks postoperatively. The bone volume fraction, number of trabeculae, and thickness of trabeculae at the repair site in the Down group, as well as the ultimate strength and failure load in the biomechanical tests, were greater than those in the other 3 groups at 8 weeks postoperatively.

CONCLUSION

Eccentric contraction promotes healing of the bone-tendon interface after rotator cuff repair in mice better than other muscle contraction patterns.

CLINICAL RELEVANCE

After clinical rotator cuff repair, patients can be rehabilitated by eccentric training to speed up the functional recovery of the shoulder joint.

Overview of muscle fatigue differences between maximal eccentric and concentric resistance exercise

Since the 1970s, researchers have studied a potential difference in muscle fatigue (acute strength loss) between maximal eccentric (ECCmax ) and concentric (CONmax ) resistance exercise. However, a clear answer to whether such a difference exists has not been established. Therefore, the aim of our paper was to overview methods and results of studies that compared acute changes in muscle strength after bouts of ECCmax and CONmax resistance exercise. We identified 30 relevant studies. Participants were typically healthy men aged 20-40 years. Exercise usually consisted of 40-100 isokinetic ECCmax and CONmax repetitions of the knee extensors or elbow flexors. Both ECCmax and CONmax exercise caused significant strength loss, which plateaued and rarely exceeded 60% of baseline, suggesting strength preservation. In upper-body muscles, strength loss at the end of ECCmax (31.4 ± 20.4%) and CONmax (33.6 ± 17.5%) exercise was similar, whereas in lower-body muscles, strength loss was less after ECCmax (13.3 ± 12.2%) than CONmax (39.7 ± 13.3%) exercise. Muscle architecture and daily use of lower-body muscles likely protects lower-body muscles from strength loss during ECCmax exercise. We also reviewed seven studies on muscle fatigue during coupled ECCmax -CONmax exercise and found similar strength loss in the ECC and CON phases. We also found evidence from three studies that more ECC than CON repetitions can be completed at equal relative loads. These results indicate that muscle fatigue may manifest differently between ECCmax and CONmax resistance exercise. An implication of the results is that prescriptions of ECC resistance exercise for lower-body muscles should account for greater fatigue resilience of these muscles compared to upper-body muscles.

Risk Factors for Failure of Conservative Management of Insertional Achilles Tendinosis

INTRODUCTION

While many patients benefit from nonoperative treatment of insertional Achilles tendinopathy (IAT), some elect for surgical debridement and reconstruction. The purpose of this study is to determine the relationship of patient demographic characteristics, comorbidity profiles, and radiological parameters with failure of conservative management of IAT.

METHODS

A retrospective chart review was performed to identify patients who received either surgical or nonsurgical treatment of IAT at an academic institution from September 2015 to June 2019 (N = 226). Demographic and comorbidity data, and the presence and magnitude of relevant radiological parameters were collected and compared between the surgically (n = 48) and nonsurgically (n = 178) treated groups.

RESULTS

No significant differences could be detected between groups regarding demographic factors or previous procedures. The surgery group was significantly more likely to have evidence of Haglund's deformity on clinical exam (83% vs 69%, P = .005), lower SF-12 physical scores (25.5 vs 35.5, P < .001), higher VAS pain scores (6.3 vs 5.3, P = .033), any mental illness (33% vs 20%, P = .044), and depression (27% vs 12%, P = .012).

DISCUSSION

Patients who received surgery for IAT were significantly more likely to have evidence of Haglund's deformity on clinical exam, depression, higher VAS pain scores, and lower SF-12 physical scores. Both patients and surgeons should be aware of the higher rates of failure of conservative treatment in these patients.

LEVEL OF EVIDENCE

Level III.

Combined Midportion Achilles and Plantaris Tendinopathy: A 1-Year Follow-Up Study after Ultrasound and Color-Doppler-Guided WALANT Surgery in a Private Setting in Southern Sweden

Background and Objectives: Chronic painful midportion Achilles combined with plantaris tendinopathy can be a troublesome condition to treat. The objective was to prospectively follow patients subjected to ultrasound (US)- and color doppler (CD)-guided wide awake, local anesthetic, no-tourniquet (WALANT) surgery in a private setting. Material and Methods: Twenty-six Swedish patients (17 men and 9 women, mean age 50 years (range 29–62)) and eight international male patients (mean age of 38 years (range 25–71)) with combined midportion Achilles and plantaris tendinopathy in 45 tendons altogether were included. All patients had had >6 months of pain and had tried non-surgical treatment with eccentric training, without effect. US + CD-guided surgical scraping of the ventral Achilles tendon and plantaris removal under local anesthesia was performed on all patients. A 4–6-week rehabilitation protocol with an immediate full-weight-bearing tendon loading regime was used. The VISA-A score and a study-specific questionnaire evaluating physical activity level and subjective satisfaction with the treatment were used for evaluation. Results: At the 1-year follow-up, 32/34 patients (43 tendons) were satisfied with the treatment result and had returned to their pre-injury Achilles tendon loading activity. There were two dropouts (two tendons). For the Swedish patients, the mean VISA-A score increased from 34 (0–64) before surgery to 93 (61–100) after surgery (p < 0.001). There were two complications, one wound rupture and one superficial skin infection. Conclusions: For patients suffering from painful midportion Achilles tendinopathy and plantaris tendinopathy, US + CD-guided surgical Achilles tendon scraping and plantaris tendon removal showed a high satisfaction rate and good functional results 1 year after surgery.

Efficacy of therapeutic ultrasound in the treatment of chronic calcific shoulder tendinitis: a randomized trial

BACKGROUND

Calcific shoulder tendinitis (CST) is characterized by hydroxyapatite crystals deposition in the rotator cuff tendons. Therapeutic exercises have been the mainstay of CST treatment, and evidence for therapeutic ultrasound (T-US) utilization and efficacy is lacking.

AIM

This study aimed to determine whether 4500 J T-US combined with therapeutic exercises is superior to therapeutic exercises alone regarding calcification size reduction and symptom improvement in chronic symptomatic CST.

DESIGN

This is a double-blind, placebo-controlled study.

SETTING

This study was conducted at a University Department for Rheumatic Diseases and Rehabilitation of a University Hospital.

POPULATION

Patients with chronic CST were analyzed.

METHODS

After eligibility allocation, 46 patients with sonographically confirmed CST were divided into two groups (56 shoulders, 26 per group). Both groups performed the same therapeutic exercises for half an hour under physiotherapist supervision. In the treatment group T-US (4500 J, 10 minutes per session at a frequency of 1 MHz and an intensity of 1.5 W/cm²), and in the placebo group, sham T-US was applied for 4 weeks. Patients were assessed for: calcification size, shoulder pain, global health (GH), shoulder mobility (ROM), handgrip strength, Health Assessment Questionnaire Disability Index (HAQ-DI), Shoulder Pain and Disability Index (SPADI), and overall rehabilitation satisfaction.

RESULTS

All assessed variables improved in both groups. A significantly greater reduction in calcification size was recorded in the treatment group compared to placebo: -10.92% (IQR 4.61% to 19.38%) versus -5.04% (2.30% to 7.22%), P=0.008. There was a significantly greater decrease in HAQ-DI, reduction of VAS GH, and an increase in hand grip strength in the treatment group, while no significant differences were observed for other parameters between the groups.

CONCLUSIONS

Our results showed that adding the 4500 J T-US to therapeutic exercises in chronic symptomatic CST therapy resulted in greater calcification size reduction immediately following the treatment, as well as hand grip strength, HAQ-DI, and VAS GH improvement.

CLINICAL REHABILITATION IMPACT

4500 J T-US combined with therapeutic exercises is more effective in reducing calcification size than therapeutic exercises alone in the treatment of chronic symptomatic CST.

Does shockwave therapy have a role on trigger thumb?—a single-case design

Background

The trigger thumb is a clinically unusual and rare phenomenon. The trigger finger is most observed on the ring or middle fingers. Clinical signs include reduced tendon excursion and the formation of nodules at the base of the metacarpals. As a result, grip strength may be reduced, making gripping tasks uncomfortable. Many treatments have been proposed to treat trigger finger symptoms; however, the effectiveness of shockwave therapy is still being contested. As a result, the purpose of this trigger thumb case study is to assess the effect of shockwave therapy on grip performance.

Case presentation

A 53-year-old housewife reported to the outpatient department with pain at the base of her right thumb, recurring locking episodes, morning pain and stiffness, and a 10-year history of diabetes. Based on the clinical presentation and physical examination of the patient, an orthopedic sports physician diagnosed it as a trigger thumb. Analgesics were initially administered, and the patient was then referred to physiotherapy for rehabilitation. All outcomes improved substantially during the follow-up after six sessions of physical therapy, which included shockwave therapy and an exercise program.

Conclusion

This study concluded that the protocol developed specifically for the treatment of the trigger thumb is efficacious. Therefore, future research with a larger number of participants is required to validate this approach.

The effect of rotator cuff physical exercise combined with electrically stimulated antagonist on shoulder rotator cuff strength

BACKGROUND

An elastic band (EB) is generally used with a low load for rotator cuff physical exercise, but the resulting increase in muscle strength is insufficient. We assessed the efficacy on external rotator muscle strength of the shoulder joint; of a hybrid training system (HTS) that resists the motion of a volitionally contracting agonist muscle using the force generated by its electrically stimulated antagonist vs. general rotator cuff exercise with EB.

METHODS

Twenty healthy men with no shoulder joint disorders were randomized to 6 weeks of triweekly 10-min rotator cuff exercise with HTS or EB in a clinical research laboratory. Isokinetic concentric external rotator muscle strength at angular velocities of 60°/s and 180°/s (CON60, CON180, respectively) and isokinetic eccentric external rotator muscle strength at an angular velocity of 60°/s (ECC60) were measured as rotator cuff function before and after 6 weeks of intervention.

RESULTS

There were no significant intergroup differences in baseline characteristics. There were statistically significant differences (p = 0.0358, p = 0.0213, respectively) in the increase in CON180 (mean ± SD) and ECC60 between the HTS group (Δ6.0 ± 6.0Nm, p = 0.015; Δ7.5 ± 4.7Nm p = 0.0007, respectively) and the EB group (Δ0.3 ± 5.2Nm, p = 0.8589; Δ1.8 ± 5.3 Nm p = 0.3133, respectively). There was a trend toward CON60 increasing in the HTS group (Δ4.7 ± 6.5Nm, p = 0.0494) which was greater than in the control group (Δ-0.9 ± 6.3Nm, p = 0.6637) (inter-group, p = 0.0677).

CONCLUSIONS

The results of this study support the conclusion that HTS is more effective for increasing external rotator muscle strength more effectively than EB. HTS would be useful for rotator cuff physical exercise.

Eccentric Exercise: Adaptations and Applications for Health and Performance

The goals of this narrative review are to provide a brief overview of the muscle and tendon adaptations to eccentric resistance exercise and address the applications of this form of training to aid rehabilitative interventions and enhance sports performance. This work is centered on the author contributions to the Special Issue entitled "Eccentric Exercise: Adaptations and Applications for Health and Performance". The major themes from the contributing authors include the need to place greater attention on eccentric exercise mode selection based on training goals and individual fitness level, optimal approaches to implementing eccentric resistance exercise for therapeutic purposes, factors that affect the use of eccentric exercise across the lifespan, and general recommendations to integrate eccentric exercise in athletic training regimens. The authors propose that movement velocity and the absorption or recovery of kinetic energy are critical components of eccentric exercise programming. Regarding the therapeutic use of eccentric resistance training, patient-level factors regarding condition severity, fitness level, and stage of rehabilitation should govern the plan of care. In athletic populations, use of eccentric exercise may improve movement competency and promote improved safety and performance of sport-specific tasks. Eccentric resistance training is a viable option for youth, young adults, and older adults when the exercise prescription appropriately addresses program goals, exercise tolerability, and compliance. Despite the benefits of eccentric exercise, several key questions remain unanswered regarding its application underscoring the need for further investigation.

Combined extracorporeal shockwave therapy and exercise for the treatment of tendinopathy: A narrative review

Tendinopathy is a chronic degenerative musculoskeletal disorder that is common in both athletes and the general population. Exercise and extracorporeal shockwave therapy (ESWT) is among the most common treatments used to mediate tendon healing and regeneration. The review presents the current understanding of mechanisms of action of ESWT and exercise in isolation and briefly synthesises evidence of their effectiveness for various tendinopathies. The central purpose of the review is to synthesize research findings investigating the combination of ESWT and exercise for five common tendinopathies (plantar heel pain, rotator cuff, lateral elbow, Achilles, and patellar tendinopathy) and provide recommendations on clinical applicability. Collectively, the available evidence indicates that ESWT combined with exercise in the form of eccentric training, tissue-specific stretching, or heavy slow resistance training are effective for specific tendinopathies and can therefore be recommended in treatment. Whilst there are at present a limited number of studies investigating combined EWST and exercise approaches, there is evidence to suggest that the combination improves outcomes in the treatment of plantar heel pain, Achilles, lateral elbow, and rotator cuff tendinopathy. However, despite overall positive outcomes in patellar tendinopathy, the combined treatment has not been shown at present to offer additional benefit over eccentric exercise alone.

Evaluation of short-term and residual effects of Kinesio taping in chronic lateral epicondylitis: A randomized, double-blinded, controlled trial

BACKGROUND

Lateral epicondylitis is degenerative tendinosis of the extensor carpi radialis brevis muscle and is the most common work/sports-related chronic musculoskeletal problem affecting the elbow.

PURPOSE

This study aimed to evaluate the short term and residual effectiveness of the Kinesio taping method on pain, grip force, quality of life, and functionality.

STUDY DESIGN

Randomized, double-blinded, controlled study.

METHODS

Subjects were 50 patients diagnosed with chronic unilateral lateral epicondylitis with a symptom duration of at least 12 weeks. During the first four weeks, the study group received a true inhibitor Kinesio taping while the control group received sham taping. In both groups, progressive stretching and strengthening exercises were given as a home program for six weeks. The primary outcome measure was the Numerical Rating Scale (NRS) for self-report of pain intensity; secondary outcome measures were Cyriax resistive muscle test evaluation, maximal grip strength, Patient- Rated Tennis Elbow Evaluation (PRTEE), and Short Form-36 (SF-36). After the treatment, patients were evaluated by the first assessor who was blinded to taping types.

RESULTS

There was a significant decrease in NRS scores overtime during the first four weeks in both groups (P < .001,) and effect sizes were large. There was no significant difference in Cyriax muscle resistance test maximal grip strength between groups (P > .05). However, there was a significant improvement in muscle strength of elbow extension and pronation in the study group detected in the intragroup analysis. Intragroup comparisons also showed a significant improvement in all subunits of the PRTEE and SF-36 except energy/vitality, social functioning, and pain in both groups (P < .05) with moderate to high effect sizes. PRTEE pain scores were significantly decreased in the study group compared to the placebo group (P < .05, d = 0.48).

CONCLUSION

The effects of Kinesio taping on muscle strength, quality of life, and function in chronic lateral epicondylitis are not superior to placebo. However, NRS scores showed that in the two weeks after Kinesio taping treatment, pain reduction persisted as a residual effect which may improve the exercise adherence and functionality.

The Beneficial Effects of Eccentric Exercise in the Management of Lateral Elbow Tendinopathy: A Systematic Review and Meta-Analysis

As a first-line treatment for lateral elbow tendinopathy (LET), eccentric exercise has been suggested as a conservative treatment method. This study aimed to investigate the impact of eccentric exercise on LET with regard to pain reduction, and strength and functional improvement. The PubMed, EMBASE, and Cochrane Central Register of Controlled Trials databases were searched, and studies up to May 2021 were included if (1) randomization was used for patient allocation, (2) the study comprised patients with LET, (3) the intervention was eccentric exercise, and (4) the primary outcomes included improvement in pain intensity, muscle strength, or function. The meta-analysis comprised of six studies, totaling 429 participants. Additional eccentric exercise with underlying adjuvant therapy significantly improved the visual analog scale (VAS) scores (standardized mean difference [SMD], −0.63; 95% confidence interval [CI], −0.90–−0.36) and muscle strength (SMD, 1.05; 95% CI, 0.78–1.33) compared with adjuvant therapy alone. Compared with the concentric or isotonic exercise group, the eccentric exercise group showed significantly improved VAS scores (SMD, −0.30; 95% CI, −0.58–−0.02). However, no differences in muscle strength and function were observed between the two groups. Eccentric exercise can improve pain and muscle strength in patients with LET. The limited number of included studies and heterogeneous exercise parameters are important when interpreting these findings.

Autoregulation in Resistance Training for Lower Limb Tendinopathy: A Potential Method for Addressing Individual Factors, Intervention Issues, and Inadequate Outcomes

Musculoskeletal disorders, such as tendinopathy, are placing an increasing burden on society and health systems. Tendinopathy accounts for up to 30% of musculoskeletal disorders, with a high incidence in athletes and the general population. Although resistance training has shown short-term effectiveness in the treatment of lower limb tendinopathy, more comprehensive exercise protocols and progression methods are required due to poor long-term outcomes. The most common resistance training protocols are predetermined and standardized, which presents significant limitations. Current standardized protocols do not adhere to scientific resistance training principles, consider individual factors, or take the importance of individualized training into account. Resistance training programs in case of tendinopathy are currently not achieving the required intensity and dosage, leading to high recurrence rates. Therefore, better methods for individualizing and progressing resistance training are required to improve outcomes. One potential method is autoregulation, which allows individuals to progress training at their own rate, taking individual factors into account. Despite the finding of their effectiveness in increasing the strength of healthy athletes, autoregulation methods have not been investigated in case of tendinopathy. The purpose of this narrative review was 3-fold: firstly, to give an overview and a critical analysis of the individual factors involved in tendinopathy and current resistance training protocols and their limitations. Secondly, to give an overview of the history, methods, and application of autoregulation strategies both in sports performance and physiotherapy. Finally, a theoretical adaptation of a current tendinopathy resistance training protocol using autoregulation methods is presented, providing an example of how the method could be implemented in clinical practice or future research.

Sleep and Injury Risk

ABSTRACT

Sleep has been found to have wide-ranging effects on sports performance and overall well-being. Recent research has found evidence relating chronic suboptimal sleep with the risk of musculoskeletal pain and sports injury. The amount of sleep that consistently has been found to be associated with increased risk of injury is ≤7 h of sleep, which when sustained for periods of at least 14 d has been associated with 1.7 times greater risk of musculoskeletal injury. However, it is unknown if sleep loss predisposes the athlete to specific types of musculoskeletal injuries. The role of sleep on musculoskeletal pain is important to understand as studies in both children and adults have found that suboptimal sleep more consistently predicts next-day pain as compared with pain predicting subsequent sleep loss. Despite the evidence that certain aspects of sleep behavior seem to increase the risk of musculoskeletal injury and pain, sleep should be considered as only a part of the athlete's overall health and well-being when assessing the athlete for risk of injury.

The implementation of resistance training principles in exercise interventions for lower limb tendinopathy: A systematic review

OBJECTIVES

The primary purpose of this systematic review is to examine the literature on resistance training interventions for lower limb tendinopathy to evaluate the proportion of interventions that implemented key resistance training principles (specificity, progression, overload, individualisation) and reported relevant prescription components (frequency, intensity, sets, repetitions) and reported intervention adherence.

METHODS

Two reviewers performed a systematic review after screening titles and abstracts based on eligibility criteria. Identified papers were obtained in full text, with data extracted regarding the implementation of resistance training principles. Included articles were evaluated by the Cochrane risk of bias tool, with a scoring tool out of 10 used for implementation and reporting of the 5 key principles. Scientific databases were searched in November 2020 and included Medline, CINAHL, AMED, and Sportsdiscus.

RESULTS

52 randomised controlled trials investigating resistance training in five different lower limb tendinopathies were included. Although most studies considered the principles of progression (92%) and individualisation (88%), only 19 studies (37%) appropriately described how this progression in resistance was achieved, and only 18 studies (35%) reported specific instruction on how individualisation was applied. Adherence was considered in 27 studies (52%), with only 17 studies (33%) reporting the levels of adherence. In the scoring criteria, only 5 studies (10%) achieved a total maximum score of 10, with 17 studies (33%) achieving a maximum score of 8 for implementing and reporting the principles of specificity, overload, progression and individualisation.

CONCLUSION

There is meaningful variability and methodological concerns regarding the application and reporting of resistance training principles, particularly progression and individualisation, along with intervention adherence throughout studies. Collectively, these findings have important implications for the prescription of current resistance training interventions, including the design and implementation of future interventions for populations with lower limb tendinopathies.

Autoregulated and individualised resistance training versus predetermined and standardised resistance training in tendinopathy: A systematic review protocol

REVIEW OBJECTIVE

To synthesise the best available evidence on the effectiveness of interventions that have used autoregulated and individualised resistance training versus predetermined and standardised resistance training in treating any tendinopathy.

INTRODUCTION

Recent evidence suggests that individualised exercise may be more effective than standardised exercise for musculoskeletal disorders such as tendinopathy. However, no systematic reviews have been conducted on the topic and optimal treatment protocols and clinical recommendations are lacking.

INCLUSION CRITERIA

Randomised controlled trials assessing the effectiveness of autoregulated and individualised resistance training versus predetermined and standardised resistance training for tendinopathy in adults will be included.

METHODS

The authors will search for a wide range of sources to find both published and unpublished studies via EBSCOhost, including, but not limited to, MEDLINE, SPORTDiscus, CINAHL, Cochrane Central Register of Controlled Trials and Allied and Complementary Medicine Database. Studies published in a language other than English will only be considered if a translation is available. The Joanna Briggs Institute systematic review methodology will be followed when conducting the review. Data synthesis will be conducted using meta-analysis or narrative synthesis, where appropriate.

Effects of Physical Training on Physical and Psychological Parameters in Individuals with Patella Tendon Myopathy: A Systematic Review and Meta-Analysis

The effectiveness of physical training on physical and psychological parameters in individuals with patella tendinopathy has not been investigated in a systematic review and meta-analysis. The aim of the present study was to determine the effects of physical exercise interventions for measures of physical and psychological performance in subjects with patella tendinopathy. A computerised systematic literature search was conducted in the electronic databases PubMed, Medline, and Web of Science from January 1960 to July 2020. Initially, 506 articles were identified for review of which eleven articles met the inclusion criteria. Our results revealed a small effect (weighted mean standardized mean difference (SMD) = 0.12; nine studies) of physical training on the psychological measure Victorian Institute of Sport Assessment–Patellar tendon scale and a medium effect (weighted mean SMD = 0.61; five studies) on the psychological measure visual analogue scale—both in favour of the intervention group. In contrast, a small effect (weighted mean SMD = −0.05; two studies) in favour of the control group was detected for the physical measure muscle power. Compared to the control condition, physical training seems to be an effective means to improve psychological but not physical parameters in individuals with patella tendinopathy; although conclusions on the latter could have been biased by the small amount of eligible studies (n = 2). In addition, the predetermined cut-off value of ≥6 for the Physiotherapy Evidence Database scale score (i.e., assessment of methodological quality) was only achieved by six out of eleven studies. Thus, further research of high methodological quality is needed to verify whether there is or is not an effect of physical training on physical parameters in persons with patella tendinopathy.

Tendinopathy

Tendinopathy describes a complex multifaceted pathology of the tendon, characterized by pain, decline in function and reduced exercise tolerance. The most common overuse tendinopathies involve the rotator cuff tendon, medial and lateral elbow epicondyles, patellar tendon, gluteal tendons and the Achilles tendon. The prominent histological and molecular features of tendinopathy include disorganization of collagen fibres, an increase in the microvasculature and sensory nerve innervation, dysregulated extracellular matrix homeostasis, increased immune cells and inflammatory mediators, and enhanced cellular apoptosis. Although diagnosis is mostly achieved based on clinical symptoms, in some cases, additional pain-provoking tests and imaging might be necessary. Management consists of different exercise and loading programmes, therapeutic modalities and surgical interventions; however, their effectiveness remains ambiguous. Future research should focus on elucidating the key functional pathways implicated in clinical disease and on improved rehabilitation protocols.

Recent advances in tendinopathy

Tendinopathy refers to the clinical diagnosis of activity-related pain resulting in a decline in tendon function. In the last few years, much has been published concerning the basic science and clinical investigation of tendinopathy and debates and discussions to new questions and points of view started many years ago. This advances review will discuss the current thinking on the basic science and clinical management of tendinopathy and in particular new findings in the tendon repair space that are relevant to the pathophysiology of tendinopathy. We will further discuss potential novel therapies on the horizon in human tendon disease.

Biologics

Biologics are a growing field that has shown immense promise for the treatment of musculoskeletal conditions both in orthopedic sports medicine and interventional pain management. These procedures utilize injection of supraphysiologic levels of platelets and growth factors to invoke the body's own inflammatory cascade to augment the healing of many bony and soft tissue conditions. While many patients improve with conservative care, there is a need to address the gap between those that improve with rehabilitation alone and those who ultimately require operative management. Orthobiologic procedures have the potential to fill this void. The purpose of this review is to summarize the basic science, evidence for use, and post-injection rehabilitation concepts of platelet-rich plasma (PRP) and mesenchymal stromal cells (MSCs) as they pertain to joints, tendons, ligaments, and the spine.

Physical therapy for tendinopathy: An umbrella review of systematic reviews and meta-analyses

OBJECTIVE

To summarize evidence in the last decade regarding the efficacy of physical therapy interventions to treat tendinopathy, as a single disease entity, as determined in systematic reviews (SRs) and/or meta-analyses (MAs).

METHODS

Electronic search of PubMed, PEDro, and Scopus database was performed from year 2010 to January 2020. The methodological quality of the identified studies was assessed using the AMSTAR 2 tool. Studies scoring 9 points or higher were further analyzed using GRADE principles.

RESULTS

40 SRs and/or MAs were included in qualitative synthesis, whereas only 5 MAs were included in quantitative synthesis. Low-level laser therapy (LLLT) intervention showed a pooled improvement in pain reduction of 1.53 cm; 95% CI, [1.14, 1.91] (I² = 1.9%, p = 0.361) on visual analogue scale, and grip strength of 9.59 kg; 95% CI, [5.90, 13.27].

CONCLUSIONS

Moderate-quality evidence may support these following interventions: LLLT revealed a statistically and potentially clinically significant improvement in pain and function on the short-term. Extracorporeal shockwave therapy showed a statistically significant enhancement in pain and function at all follow-up durations; however, its clinical significance was undetermined. Eccentric exercise was supported by qualitative evidence only. Caution is advised when interpreting results due to possible pathological differences in tendinopathy at each region.

Comparative study of treatment interventions for patellar tendinopathy: a protocol for a randomised controlled trial

INTRODUCTION

Patellar tendinopathy is a degenerative disease of the patellar tendon, which affects athletes from a variety of sports, and is especially predominant in sports involving high-impact jumping. The aim of this study is to determine the additional effect of two interventions combined with eccentric exercise and compare which one is the most effective at short-term and long-term follow-up for patients with patellar tendinopathy.

METHODS AND ANALYSIS

This study is a randomised controlled trial with blinded participants. Measurements will be carried out by a specially trained blinded assessor. A sample of 57 patients with a medical diagnosis of patellar tendinopathy will participate in this study and will be divided into three treatment groups. Eligible participants will be randomly allocated to receive either: (a) treatment group with percutaneous needle electrolysis, (b) treatment group with dry needling or (c) treatment group with placebo needling. In addition, all groups will perform eccentric exercise. Functionality and muscle strength parameters, pain, ultrasound appearances and patient perceived quality of life shall be evaluated using the Victorian Institute of Sports Assessment for patellar (VISA-P), jump tests, Visual Analogue Scale, ultrasound images and Short Form-36 (SF-36), respectively. Participants will be assessed at baseline, at 10 weeks and at 22 weeks after baseline. The expected findings will allow us to advance in the treatment of this injury, as they will help determine whether a needling intervention has additional effects on an eccentric exercise programme and whether any of the needling modalities is more effective than the other.

ETHICS AND DISSEMINATION

This protocol has been approved by the Ethics Committee of Aragon (N° PI15/0017). The trial will be conducted in accordance with the Declaration of Helsinki.

TRIAL REGISTRATION NUMBER

NCT02498795.

Triceps Surae Muscle Architecture Adaptations to Eccentric Training

Background

Eccentric exercises have been used in physical training, injury prevention, and rehabilitation programs. The systematic use of eccentric training promotes specific morphological adaptations on skeletal muscles. However, synergistic muscles, such as the triceps surae components, might display different structural adaptations due to differences in architecture, function, and load sharing. Therefore, the purpose of this study was to determine the effects of an eccentric training program on the triceps surae (GM, gastrocnemius medialis; GL, gastrocnemius lateralis; and SO, soleus) muscle architecture.

Methods

Twenty healthy male subjects (26 ± 4 years) underwent a 4-week control period followed by a 12-week eccentric training program. Muscle architecture [fascicle length (FL), pennation angle (PA), and muscle thickness (MT)] of GM, GL, and SO was evaluated every 4 weeks by ultrasonography.

Results

Fascicle lengths (GM: 13.2%; GL: 8.8%; SO: 21%) and MT (GM: 14.9%; GL: 15.3%; SO: 19.1%) increased from pre- to post-training, whereas PAs remained similar. GM and SO FL and MT increased up to the 8th training week, whereas GL FL increased up to the 4th week. SO displayed the highest, and GL the smallest gains in FL post-training.

Conclusion

All three synergistic plantar flexor muscles increased FL and MT with eccentric training. MT increased similarly among the synergistic muscles, while the muscle with the shortest FL at baseline (SO) showed the greatest increase in FL.

General Practitioners' recommendations of self-directed-exercises for musculoskeletal problems and perceived barriers and facilitators to doing so: a mixed methods study

BACKGROUND

Musculoskeletal problems substantially impact the demand for and the finances of the United Kingdom's National Health Service. Some of this demand and cost could be alleviated if patients use self-directed-exercises. The present study aims first to establish whether general practitioners already recommend self-directed-exercises and second to describe barriers and facilitators to making such recommendations.

METHOD

The design of the current study included surveys and interviews. The surveys were designed to draw out participants' tendency to recommend self-directed-exercises and their behavioral drivers to do so. The drivers investigated include 14 domains described by the Theoretical Domains Framework. The surveys were completed online and the responses were analyzed using descriptive reports and regression analyses. The interviews were designed to more fully understand participants' experiences recommending self-directed-exercises according to the same framework. The interviews were audio-taped, transcribed, and thematically analyzed.

RESULTS

The survey found that the following domains significantly predicted participants' tendency to recommend self-directed-exercises: Environmental contexts and resources, Goals, Intentions, Knowledge, Memory attention and decision processes, and Social/professional role. The interviews brought out four themes that could be leveraged to increase general practitioners' tendency to recommend self-directed-exercises: (1) Practitioners' beliefs about self-directed-exercises being effective, (2) Patients' motivations to engage in self-directed-exercises, (3) Time constraints, and (4) The ease with which practitioners can recommend self-directed-exercises.

CONCLUSIONS

Most general practitioners already recommend self-directed-exercises, though they note significant barriers that may prevent them from doing so. General practitioners' tendency to recommend self-directed-exercises would be bolstered by creating a respected central resource of exercise pamphlets. These pamphlets should clearly describe how different self-directed-exercises should be performed and evidence supporting their effectiveness.

Proposing a Patellar Tendinopathy Screening tool following a systematic review

BACKGROUND

Patellar tendinopathy (PT) is an overuse injury of the knee. The mechanism of injury is associated with repetitive stress on the patellar tendon of the knee as a result of explosive movement. Patellar tendinopathy is prevalent in all populations and is associated with intrinsic and extrinsic risk factors.

OBJECTIVES

Primarily, the objective was to report on the intrinsic and extrinsic risk factors for PT, entailing a systematic review of the literature; the secondary objective was to use these risk factors to compile a proposed PT screening tool from the review and standard outcome measures.

METHOD

A systematic review was undertaken according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Elimination criteria of the articles included duplicates, titles, abstracts and methodological quality. The evidence was collected, characterised with regard to the intrinsic and extrinsic risk factors and summarised descriptively.

RESULTS

The search yielded 157 feasible articles prior to commencement of article elimination. Six articles were included with a mean methodological quality score of 69%. Eight intrinsic and five extrinsic risk factors were identified. These identified risk factors are all relevant to the pathology and formed the basis for a proposed PT screening tool. The Victorian Institute of Sports Assessment for Patellar Tendinopathy Questionnaire, Visual Analog Scale and the Pain Provocation Test are also included in the proposed test.

CONCLUSION

Intrinsic and extrinsic risk factors for PT were identified, and consequently, the proposed PT screening tool was formulated for possible future testing in appropriate studies.

CLINICAL IMPLICATIONS

Prevention of PT through intrinsic and extrinsic risk factor identification, and implementation in the clinical setup as a possible outcome measurement tool with which to verify functional improvement in PT rehabilitation.

A potential new role for myofibroblasts in remodeling of sub-rupture fatigue tendon injuries by exercise

Tendons are ineffective at repairing sub-rupture fatigue injuries. Accordingly, we evaluated whether an exercise protocol that we have previously found to decrease structural damage kinks in fatigue damaged tendons, leads to improvement in mechanical properties. We hypothesized that exercise that promotes repair of fatigue damage will decrease apoptosis and increase the population of myofibroblasts. Rat patellar tendons underwent in vivo fatigue loading for 500 or 7200 cycles. Animals resumed cage activity for 2-weeks, then either remained cage active or began treadmill running until sacrifice at 4- or 10-weeks post-fatigue loading. Exercise following fatigue damage increased the stiffness back towards naïve levels, decreased apoptosis and increased the population of myofibroblasts. Next, proteins associated with inhibition of apoptosis (Collagen VI) or activation of myofibroblast (pSmad 2/3, fibrillin, integrin subunits αV and α5) were evaluated. Data suggests that collagen VI may not be integral to inhibition of apoptosis in this context. Exercise increased pSmad 2/3 and fibrillin in the insertion region for the 7200-cycles group. In addition, exercise decreased integrin αV and increased integrin α5 in fatigue damaged tendons. Data suggests that a decrease in apoptosis and an increase in population of myofibroblasts may be integral to remodeling of fatigue damaged tendons.

What Is the Most Effective Eccentric Stretching Position in Lateral Elbow Tendinopathy?

Background

A variety of treatment options suggest that the optimal treatment strategy for lateral elbow tendinopathy (LET) is not known, and further research is needed to discover the most effective treatment for LET. The purpose of the present study was to verify the most effective position of eccentric stretching for the extensor carpi radialis brevis (ECRB) in vivo using ultrasonic shear wave elastography.

Methods

A total of 20 healthy males participated in this study. Resting position was defined as 90° elbow flexion and neutral position of the forearm and wrist. Elongation of the ECRB was measured for four stretching maneuvers (forearm supination/pronation and wrist extension/flexion) at two elbow angles (90° flexion and full extension). The shear elastic modulus, used as the index of muscle elongation, was computed using ultrasonic shear wave elastography for the eight aforementioned stretching maneuverangle combinations.

Results

The shear elastic modulus was the highest in elbow extension, forearm pronation, and wrist flexion. The shear elastic moduli of wrist flexion with any forearm and elbow position were significantly higher than the resting position. There was no significant difference associated with elbow and forearm positions except for elbow extension, forearm pronation, and wrist flexion positions.

Conclusions

This study determined that elbow extension, forearm pronation, and wrist flexion was the most effective eccentric stretching for the ECRB in vivo.

COMPARISON OF FUNCTIONAL ACTIVITIES ON STRUCTURAL CHANGES OF THE INFERIOR PATELLAR POLE

Background

It is well known that eccentric and concentric exercise produce varied amounts of stress on the connective tissues. Diagnostic ultrasound has been used to measure these structural changes by observing fascicle length, angle, and thickness; however, there is a lack of evidence comparing the structural changes as it relates to eccentric, concentric, and stretching protocols.

Purpose

The purpose of this study was to compare the acute effects of static stretching, eccentric, concentric, and a combination of eccentric/concentric exercises on structural changes of the muscle tendon unit at the inferior patellar pole utilizing the diagnostic ultrasound.

Study Design

A repeated measures 2 × 4 within factorial study design with repeated measures on both factors was used to determine the differences in patellar tendon thickness within and between groups.

Methods

Forty-seven healthy subjects were screened for any lower extremity deficits or orthopaedic pathology. Forty-four (N=44) subjects completed all four protocols; the attrition was due to injuries to the lower extremity, occurring unrelated to the study. A baseline measurement of the anterior inferior patellar tendon was performed with the diagnostic ultrasound prior to each participant completing one of the four interventions per week over a four-week period. Interventions completed by each participant included static stretching, concentric, eccentric, and combined concentric and eccentric exercises. Immediately following each intervention, a post-intervention inferior patellar tendon measurement was recorded using the diagnostic ultrasound.

Results

Significant differences in anterior to posterior tendon thickness of the inferior patellar tendon were observed between pre (4.983 ± 0.041mm) and post (5.198 ± 0.055mm) measurements (p<0.0005) for the main effect of time. However, no differences in tendon thickness were noted comparing each intervention to one another (p=0.351).

Conclusion

Differences in tendon thickness were noted acutely for pre- to post measurements across all interventions. Further research is needed to determine if differences in tendon thickness exist with a longer duration of exercise over time and with different types of intervention.

THE REHABILITATION OF A RUNNER WITH ILIOPSOAS TENDINOPATHY USING AN ECCENTRIC-BIASED EXERCISE-A CASE REPORT

Background and Purpose

While there is much discussion about tendinopathy in the literature, there is little reference to the less common condition of iliopsoas tendinopathy, and no documentation of the condition in runners. The iliopsoas is a major decelerator of the hip and eccentric loading of the iliopsoas is an important component of energy transfer during running. Eccentric training is a thoroughly researched method of treating tendinopathy but has shown mixed results. The purpose of this case report is to describe the rehabilitation of a runner with iliopsoas tendinopathy, and demonstrate in a creative eccentric-biased technique to assist with treatment. A secondary objective is to illustrate how evidence on intervention for other tendinopathies was used to guide rehabilitation of this seldom described condition.

Case Description

The subject was a 39-year-old female middle distance runner diagnosed with iliopsoas tendinopathy via ultrasound, after sudden onset of left anterior groin pain. Symptoms began after a significant increase in running load, and persisted, despite rest, for three months. The intervention consisted of an eccentric-biased hip flexor exercise, with supportive kinetic chain exercises and progressive loading in a return to running program.

Outcomes

The Copenhagen Hip and Groin Outcome Score, the Visual Analogue Scale, the Global Rating of Change Scale and manual muscle testing scores all improved after 12 weeks of intervention with further improvement at the five-year follow up. After 12 weeks of intervention, the subject was running without restriction and had returned to her pre-injury running mileage at the five-year follow up.

Discussion

The eccentric-biased exercise in conjunction with exercises addressing the kinetic chain and a progressive tendon loading program, were successful in the rehabilitation of this subject with iliopsoas tendinopathy. This case report is the first to provide a description on the rehabilitation of iliopsoas tendinopathy, and offers clinicians suggestions and guidance for treatment and exercise choice in the clinical environment.

Level of Evidence

5.

Open Repair of Quadriceps Tendon With Suture Anchors and Semitendinosus Tendon Allograft Augmentation

Quadriceps tendinopathy in an increasingly recognized diagnosis can lead to quadriceps tendon rupture, especially in the older population. It can be caused by repeated micro trauma or also predisposed by systemic diseases such as diabetes mellitus and connective tissue disorders that can in turn lead to extensor mechanism deficits. Although a trial of conservative treatment is advocated, operative treatment should be performed in cases of persistent pain, extension deficit, or complete rupture of the tendon. The purpose of this Technical Note is to describe in detail a procedure for open repair of a quadriceps tendon, with significant degeneration due to quadriceps tendinopathy, using suture anchors and semitendinosus tendon allograft augmentation.

Poor reproducibility of compression elastography in the Achilles tendon: same day and consecutive day measurements

OBJECTIVE

To determine the reproducibility of compression elastography (CE) when measuring strain data, a measure of stiffness of the human Achilles tendon in vivo, over consecutive measures, consecutive days and when using different foot positions.

MATERIALS AND METHODS

Eight participants (4 males, 4 females; mean age 25.5 ± 2.51 years, range 21-30 years; height 173.6 ± 11.7 cm, range 156-189 cm) had five consecutive CE measurements taken on one day and a further five CE measures taken, one per day, at the same time of day, every day for a consecutive 5-day period. These 80 measurements were used to assess both the repeatability and reproducibility of the technique. Means, standard deviations, coefficient of variation (CV), Pearson correlation analysis (R) and intra-class correlation coefficients (ICC) were calculated.

RESULTS

For CE data, all CVs were above 53%, R values indicated no-to-weak correlations between measures at best (range 0.01-0.25), and ICC values were all classified in the poor category (range 0.00-0.11). CVs for length and diameter measures were acceptably low indicating a high level of reliability.

CONCLUSIONS

Given the wide variation obtained in the CE results, it was concluded that CE using this specific system has a low level of reproducibility for measuring the stiffness of the human Achilles tendon in vivo over consecutive days, consecutive measures and in different foot positions.

Current trends in tendinopathy: consensus of the ESSKA basic science committee. Part I: biology, biomechanics, anatomy and an exercise-based approach

Chronic tendinopathies represent a major problem in the clinical practice of sports orthopaedic surgeons, sports doctors and other health professionals involved in the treatment of athletes and patients that perform repetitive actions. The lack of consensus relative to the diagnostic tools and treatment modalities represents a management dilemma for these professionals. With this review, the purpose of the ESSKA Basic Science Committee is to establish guidelines for understanding, diagnosing and treating this complex pathology.

Treatment Options for Patellar Tendinopathy: A Systematic Review

PURPOSE

To compare the efficacy of common invasive and noninvasive patellar tendinopathy (PT) treatment strategies.

METHODS

A systematic search was performed in PubMed, Google Scholar, CINAHL, UptoDate, Cochrane Reviews, and SPORTDiscus. Fifteen studies met the following inclusion criteria: (1) therapeutic outcome trial for PT, and (2) Victorian Institute of Sports Assessment was used to assess symptom severity at follow-up. Methodological quality and reporting bias were evaluated with a modified Coleman score and Begg's and Egger's tests of bias, respectively.

RESULTS

A total of 15 studies were included. Reporting quality was high (mean Coleman score 86.0, standard deviation 9.7), and there was no systematic evidence of reporting bias. Increased duration of symptoms resulted in poorer outcomes regardless of treatment (0.9% decrease in improvement per additional month of symptoms; P = .004). Eccentric training with or without core stabilization or stretching improved symptoms (61% improvement in the Victorian Institute of Sports Assessment score, 95% confidence interval [CI] 53% to 69%). Surgery in patients refractory to nonoperative treatment also improved symptoms (57%, 95% CI 52% to 62%) with similar outcomes among arthroscopic and open approaches. Results from shockwave (54%, 95% CI 22% to 87%) and platelet-rich plasma (PRP) studies (55%, 95% CI 5% to 105%) varied widely though PRP may accelerate early recovery. Finally, steroid injection provided no benefit (20%, 95% CI -20% to 60%).

CONCLUSIONS

Initial treatment of PT can consist of eccentric squat-based therapy, shockwave, or PRP as monotherapy or an adjunct to accelerate recovery. Surgery or shockwave can be considered for patients who fail to improve after 6 months of conservative treatment. Corticosteroid therapy should not be used in the treatment of PT.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II-IV studies.

Effectiveness of Shockwave Treatment Combined With Eccentric Training for Patellar Tendinopathy: A Double-Blinded Randomized Study

OBJECTIVE

To evaluate the effectiveness of a combined treatment of focused shockwave therapy (ESWT) and eccentric training compared with sham-shockwave therapy (placebo) and eccentric training in participants with patellar tendinopathy (PT) after 24 weeks.

DESIGN

Randomized controlled trial.

SETTING

Sports medicine departments of a university hospital and a general hospital in the Netherlands.

PARTICIPANTS

Fifty-two physically active male and female participants with a clinical diagnosis of PT (mean age: 28.6 years; range, 18-45) were randomly allocated to the ESWT (n = 22) or sham shockwave (n = 30).

INTERVENTIONS

Extracorporeal shockwave therapy and sham shockwave were applied in 3 sessions at 1-week intervals with a piezoelectric device. All participants were instructed to perform eccentric exercises (3 sets of 15 repetitions twice a day) for 3 months on a decline board at home.

MAIN OUTCOME MEASURES

The Victorian Institute of Sport Assessment-Patella (VISA-P) scores (primary), pain scores during functional knee loading tests, and Likert score (secondary) were registered at baseline and at 6, 12, and 24 weeks after the start with the ESWT or sham-shockwave treatment.

RESULTS

No significant differences for the primary and secondary outcome measures were found between the groups. In the ESWT/eccentric group, the VISA-P increased from 54.5 ± 15.4 to 70.9 ± 17.8, whereas the VISA-P in the sham-shockwave/eccentric group increased from 58.9 ± 14.6 to 78.2 ± 15.8 (between-group change in VISA-P at 24 weeks -4.8; 95% confidence interval, -12.7 to 3.0, P = 0.150).

CONCLUSIONS

This study showed no additional effect of 3 sessions ESWT in participants with PT treated with eccentric exercises. The results should be interpreted with caution because of small sample size and considerable loss to follow-up, particularly in the ESWT group.

Hamstring Injuries in the Athlete: Diagnosis, Treatment, and Return to Play

Hamstring injuries are very common in athletes. Acute hamstring strains can occur with high-speed running or with excessive hamstring lengthening. Athletes with proximal hamstring tendinopathy often do not report a specific inciting event; instead, they develop the pathology from chronic overuse. A thorough history and physical examination is important to determine the appropriate diagnosis and rule out other causes of posterior thigh pain. Conservative management of hamstring strains involves a rehabilitation protocol that gradually increases intensity and range of motion, and progresses to sport-specific and neuromuscular control exercises. Eccentric strengthening exercises are used for management of proximal hamstring tendinopathy. Studies investigating corticosteroid and platelet-rich plasma injections have mixed results. Magnetic resonance imaging and ultrasound are effective for identification of hamstring strains and tendinopathy but have not demonstrated correlation with return to play. The article focuses on diagnosis, treatment, and return-to-play considerations for acute hamstring strains and proximal hamstring tendinopathy in the athlete.

Eccentric Exercise Program Design: A Periodization Model for Rehabilitation Applications

The applied use of eccentric muscle actions for physical rehabilitation may utilize the framework of periodization. This approach may facilitate the safe introduction of eccentric exercise and appropriate management of the workload progression. The purpose of this data-driven Hypothesis and Theory paper is to present a periodization model for isokinetic eccentric strengthening of older adults in an outpatient rehabilitation setting. Exemplar and group data are used to describe the initial eccentric exercise prescription, structured familiarization procedures, workload progression algorithm, and feasibility of the exercise regimen. Twenty-four men (61.8 ± 6.3 years of age) completed a 12-week isokinetic eccentric strengthening regimen involving the knee extensors. Feasibility and safety of the regimen was evaluated using serial visual analog scale (VAS, 0–10) values for self-reported pain, and examining changes in the magnitude of mean eccentric power as a function of movement velocity. Motor learning associated with the familiarization sessions was characterized through torque-time curve analysis. Total work was analyzed to identify relative training plateaus or diminished exercise capacity during the progressive phase of the macrocycle. Variability in the mean repetition interval decreased from 68 to 12% during the familiarization phase of the macrocycle. The mean VAS values were 2.9 ± 2.7 at the start of the regimen and 2.6 ± 2.9 following 12 weeks of eccentric strength training. During the progressive phase of the macrocycle, exercise workload increased from 70% of the estimated eccentric peak torque to 141% and total work increased by 185% during this training phase. The slope of the total work performed across the progressive phase of the macrocycle ranged from −5.5 to 29.6, with the lowest slope values occurring during microcycles 8 and 11. Also, mean power generation increased by 25% when eccentric isokinetic velocity increased from 60 to 90° s⁻¹ while maintaining the same workload target. The periodization model used in this study for eccentric exercise familiarization and workload progression was feasible and safe to implement within an outpatient rehabilitation setting. Cyclic implementation of higher eccentric movement velocities, and the addition of active recovery periods, are featured in the proposed theoretical periodization model for isokinetic eccentric strengthening.

No evidence for the use of stem cell therapy for tendon disorders: a systematic review

INTRODUCTION

Stem cells have emerged as a new treatment option for tendon disorders. We systematically reviewed the current evidence for stem cell therapy in tendon disorders.

METHODS

Randomised and non-randomised controlled trials, cohort studies and case series with a minimum of 5 cases were searched in MEDLINE, CENTRAL, EMBASE, CINAHL, PEDro and SPORTDiscus. In addition, we searched grey literature databases and trial registers. Only human studies were included and no time or language restrictions were applied to our search. All references of included trials were checked for possibly eligible trials. Risk of bias assessment was performed using the Cochrane risk of bias tool for controlled trials and the Newcastle-Ottawa scale for case series. Levels of evidence were assigned according to the Oxford levels of evidence.

RESULTS

4 published and three unpublished/pending trials were found with a total of 79 patients. No unpublished data were available. Two trials evaluated bone marrow-derived stem cells in rotator cuff repair surgery and found lower retear rates compared with historical controls or the literature. One trial used allogenic adipose-derived stem cells to treat lateral epicondylar tendinopathy. Improved Mayo Elbow Performance Index, Visual Analogue Pain scale and ultrasound findings after 1-year follow-up compared with baseline were found. Bone marrow-derived stem cell-treated patellar tendinopathy showed improved International Knee Documentation Committee, Knee injury and Osteoarthritis Outcome Score subscales and Tegner scores after 5-year follow-up. One trial reported adverse events and found them to be mild (eg, swelling, effusion). All trials were at high risk of bias and only level 4 evidence was available.

CONCLUSIONS

No evidence (level 4) was found for the therapeutic use of stem cells for tendon disorders. The use of stem cell therapy for tendon disorders in clinical practice is currently not advised.