Effect of a 12-week Eccentric and Isometric Training in Achilles Tendinopathy on the Gastrocnemius Muscle: an Ultrasound Shear Wave Elastography Study

Exercise therapy for tendinopathy: a mixed-methods evidence synthesis exploring feasibility, acceptability and effectiveness

Background

Tendinopathy is a common, painful and functionally limiting condition, primarily managed conservatively using exercise therapy.

Review questions

(i) What exercise interventions have been reported in the literature for which tendinopathies? (ii) What outcomes have been reported in studies investigating exercise interventions for tendinopathy? (iii) Which exercise interventions are most effective across all tendinopathies? (iv) Does type/location of tendinopathy or other specific covariates affect which are the most effective exercise therapies? (v) How feasible and acceptable are exercise interventions for tendinopathies?

Methods

A scoping review mapped exercise interventions for tendinopathies and outcomes reported to date (questions i and ii). Thereafter, two contingent systematic review workstreams were conducted. The first investigated a large number of studies and was split into three efficacy reviews that quantified and compared efficacy across different interventions (question iii), and investigated the influence of a range of potential moderators (question iv). The second was a convergent segregated mixed-method review (question v). Searches for studies published from 1998 were conducted in library databases (n = 9), trial registries (n = 6), grey literature databases (n = 5) and Google Scholar. Scoping review searches were completed on 28 April 2020 with efficacy and mixed-method search updates conducted on 19 January 2021 and 29 March 2021.

Results

Scoping review - 555 included studies identified a range of exercise interventions and outcomes across a range of tendinopathies, most commonly Achilles, patellar, lateral elbow and rotator cuff-related shoulder pain. Strengthening exercise was most common, with flexibility exercise used primarily in the upper limb. Disability was the most common outcome measured in Achilles, patellar and rotator cuff-related shoulder pain; physical function capacity was most common in lateral elbow tendinopathy. Efficacy reviews - 204 studies provided evidence that exercise therapy is safe and beneficial, and that patients are generally satisfied with treatment outcome and perceive the improvement to be substantial. In the context of generally low and very low-quality evidence, results identified that: (1) the shoulder may benefit more from flexibility (effect sizeResistance:Flexibility = 0.18 [95% CrI 0.07 to 0.29]) and proprioception (effect sizeResistance:Proprioception = 0.16 [95% CrI -1.8 to 0.32]); (2) when performing strengthening exercise it may be most beneficial to combine concentric and eccentric modes (effect sizeEccentricOnly:Concentric+Eccentric = 0.48 [95% CrI -0.13 to 1.1]; and (3) exercise may be most beneficial when combined with another conservative modality (e.g. injection or electro-therapy increasing effect size by ≈0.1 to 0.3). Mixed-method review - 94 studies (11 qualitative) provided evidence that exercise interventions for tendinopathy can largely be considered feasible and acceptable, and that several important factors should be considered when prescribing exercise for tendinopathy, including an awareness of potential barriers to and facilitators of engaging with exercise, patients' and providers' prior experience and beliefs, and the importance of patient education, self-management and the patient-healthcare professional relationship.

Limitations

Despite a large body of literature on exercise for tendinopathy, there are methodological and reporting limitations that influenced the recommendations that could be made.

Conclusion

The findings provide some support for the use of exercise combined with another conservative modality; flexibility and proprioception exercise for the shoulder; and a combination of eccentric and concentric strengthening exercise across tendinopathies. However, the findings must be interpreted within the context of the quality of the available evidence.

Future work

There is an urgent need for high-quality efficacy, effectiveness, cost-effectiveness and qualitative research that is adequately reported, using common terminology, definitions and outcomes.

Study registration

This project is registered as DOI: 10.11124/JBIES-20-00175 (scoping review); PROSPERO CRD 42020168187 (efficacy reviews); https://osf.io/preprints/sportrxiv/y7sk6/ (efficacy review 1); https://osf.io/preprints/sportrxiv/eyxgk/ (efficacy review 2); https://osf.io/preprints/sportrxiv/mx5pv/ (efficacy review 3); PROSPERO CRD42020164641 (mixed-method review).

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) HTA programme and will be published in full in HTA Journal; Vol. 27, No. 24. See the NIHR Journals Library website for further project information.

Identifying characteristics of resistance-based therapeutic exercise interventions for Achilles tendinopathy: A scoping review

OBJECTIVE

This scoping review describes resistance-based therapeutic exercise intervention characteristics for Achilles tendinopathy (AT) treatment (e.g., therapeutic dose, underlying mechanisms targeted by exercise) and assesses participant reporting characteristics.

METHODS

Seven electronic databases were searched; studies delivering a resistance exercise-focused treatment for individuals with AT were included. The Template for Intervention Description and Replication (TIDieR) and the ICON 2019 'Recommended standards for reporting participant characteristics in tendinopathy research' checklists framed data extraction, and study quality was assessed using the Mixed Methods Appraisal Tool 2018 version.

RESULTS

68 publications (describing 59 studies and 72 exercise programs) were included. Results demonstrate that therapeutic exercise interventions for AT are well reported according to the TIDieR checklist, and participant characteristics are well reported according to the ICON checklist. Various underlying therapeutic mechanisms were proposed, with the most common being increasing tendon strength, increasing calf muscle strength, and enhancing collagen synthesis.

CONCLUSIONS

While evidence suggests that resistance-based therapeutic exercise interventions are effective in treating AT, more reporting on program fidelity, adherence, and compliance is needed. By summarizing currently published AT exercise programs and reporting key intervention characteristics in a single location, this review can assist clinicians in developing individualized resistance training programs for people with AT.

Can we really say getting stronger makes your tendon feel better? No current evidence of a relationship between change in Achilles tendinopathy pain or disability and changes in triceps Surae structure or function when completing rehabilitation: a systematic review

OBJECTIVES

Determine if improvements in pain and disability in patients with mid-portion Achilles tendinopathy relate to changes in muscle structure and function whilst completing exercise rehabilitation.

DESIGN

A systematic review exploring the relationship between changes in pain/disability and muscle structure/function over time, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

METHODS

Six online databases and the grey literature were searched from database inception to 16th December 2022 whereas clinical trial registries were searched from database inception to 11th February 2020. We included clinical studies where participants received exercise rehabilitation (±placebo interventions) for mid-portion Achilles tendinopathy if pain/disability and Triceps Surae structure/function were measured. We calculated Cohen's d (95 % confidence intervals) for changes in muscle structure/function over time for individual studies. Data were not pooled due to heterogeneity. Study quality was assessed using a modified Newcastle-Ottawa Scale.

RESULTS

Seventeen studies were included for synthesis. No studies reported the relationship between muscle structure/function and pain/disability changes. Twelve studies reported muscle structure/function outcome measures at baseline and at least one follow-up time-point. Three studies reported improvements in force output after treatment; eight studies demonstrated no change in structure or function; one study did not provide a variation measure, precluding within group change over time calculation. All studies were low quality.

CONCLUSIONS

No studies explored the relationship between changes in tendon pain and disability and changes in muscle structure and function. It is unclear whether current exercise-based rehabilitation protocols for mid-portion Achilles tendinopathy improve muscle structure or function.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO (registration number: CRD42020149970).

Eccentric exercise is more effective than other exercises in the treatment of mid-portion Achilles tendinopathy: systematic review and meta-analysis

Achilles tendinopathy (AT) is one of the most frequent overuse injuries in the ankle. The evidence base for its conservative management AT continues to evolve, but there is still a gap in the evidence for the efficacy of any modality of treatment in high-quality studies. This systematic review and meta-analysis investigated the efficacy of EE in improving pain and function in adult patients with mid-portion Achilles tendinopathy compared to other forms of exercise. A search was performed in PubMed, BIREME, SportDiscus, Cinahl, Web of Science and PEDro, in November 2022. The methodological quality was evaluated using the Risk of Bias 2 tool (RoB2) of the Cochrane collaboration, and the meta-analysis was performed using the Review Manager 5.1 program. 2024 articles were identified and eight fulfilled the inclusion criteria. RoB2 presented a final score with 62.5% of the studies presented "some concerns", and 37.5% (five and three articles, respectively) presenting "high risk" of bias. EE was effective for the managment of AT. The only variable for which a meta-analysis was possible was pain (five articles), analysed with the visual analogue scale/numerical visual scale. The mean difference (MD) in treatment effect using EE was - 1.21 (- 2.72 to - 0.30) with a 95% of confidence interval (CI), thus identifying a significant positive effect for the improvement of pain in patients with AT in whom EE was used. EE is effective in the management of AT. The meta-analysis shows the need for appropriately powered randomized controlled trials with better design, the use of standard outcome measures and well-planned protocols for conservative management of AT.Level of evidence: Level 1.Registration: CRD42018118016.

Intra individual comparison of unilateral Achilles tendinopathy using B-mode, power Doppler, ultrasound tissue characterization and shear wave elastography

BACKGROUND

The asymptomatic side of unilateral Achilles tendinopathy (AT) is used as a reference in ultrasound. However, this procedure has not been evaluated in a comparative analysis using B-mode (B-US), power Doppler (PD-US), ultrasound tissue characterization (UTC) and shear wave elastography (SWE).

METHODS

Retrospective cross-sectional study. Tendons were assigned to 3 groups: 1) asymptomatic side of unilateral AT N.=55; 2) symptomatic side of unilateral AT N.=55; and 3) young reference group N.=29. The following parameters were analyzed separately for the insertion and midportion: UTC (echo type I, II, III, IV), B-US (diameter, cross sectional area), PD-US (Öhberg Score) and SWE (SWE 3 mm, SWE area) using a Wilcoxon Test (group 1 vs. 2) and a Kruskal-Wallis Test (group 1 vs. 2 vs. 3).

RESULTS

The Wilcoxon Test making an isolated comparison between group 1 vs. 2 revealed a significant difference for all parameters of B-US, PD-US, UTC and SWE (P<0.001, P=0.042), except for the insertion in UTC. However, in the overall analysis including the reference group, the Kruskal-Wallis Test could only detect a significant difference between group 1 vs. 2 for PD-US (P<0.001). Thus, group 1 and 2 had significantly more pathological parameters in B-US (P<0.001, P=0.027), SWE (P<0.001, P=0.008) and UTC (type I, III, IV P<0.001) in both, insertion and midportion, compared to the reference group.

CONCLUSIONS

The asymptomatic side of unilateral AT seems to show subclinical tendons alterations in B-US, SWE and UTC in comparison to a young and healthy control group. The asymptomatic side of unilateral AT especially with detectable neovascularization might be at risk for future symptoms. Further studies must examine whether the asymptomatic side can still serve as a reference for intra individual comparison in clinical evaluation.