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.

Effect of resistance exercise dose components for tendinopathy management: a systematic review with meta-analysis

OBJECTIVE

To investigate potential moderating effects of resistance exercise dose components including intensity, volume and frequency, for the management of common tendinopathies.

DESIGN

Systematic review with meta-analysis and meta-regressions.

DATA SOURCES

Including but not limited to: MEDLINE, CINAHL, SPORTDiscus, ClinicalTrials.gov and ISRCTN Registry.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised and non-randomised controlled trials investigating resistance exercise as the dominant treatment class, reporting sufficient information regarding ≥2 components of exercise dose.

RESULTS

A total of 110 studies were included in meta-analyses (148 treatment arms (TAs), 3953 participants), reporting on five tendinopathy locations (rotator cuff: 48 TAs; Achilles: 43 TAs; lateral elbow: 29 TAs; patellar: 24 TAs; gluteal: 4 TAs). Meta-regressions provided consistent evidence of greater pooled mean effect sizes for higher intensity therapies comprising additional external resistance compared with body mass only (large effect size domains: β BodyMass: External = 0.50 (95% credible interval (CrI): 0.15 to 0.84; p=0.998); small effect size domains (β BodyMass: External = 0.04 (95% CrI: -0.21 to 0.31; p=0.619)) when combined across tendinopathy locations or analysed separately. Greater pooled mean effect sizes were also identified for the lowest frequency (less than daily) compared with mid (daily) and high frequencies (more than once per day) for both effect size domains when combined or analysed separately (p≥0.976). Evidence for associations between training volume and pooled mean effect sizes was minimal and inconsistent.

SUMMARY/CONCLUSION

Resistance exercise dose is poorly reported within tendinopathy management literature. However, this large meta-analysis identified some consistent patterns indicating greater efficacy on average with therapies prescribing higher intensities (through inclusion of additional loads) and lower frequencies, potentially creating stronger stimuli and facilitating adequate recovery.

The Predictive Validity of Individualised Load-Velocity Relationships for Predicting 1RM: A Systematic Review and Individual Participant Data Meta-analysis

BACKGROUND

Load-velocity relationships are commonly used to estimate one-repetition maximums (1RMs). Proponents suggest these estimates can be obtained at high frequencies and assist with manipulating loads according to session-by-session fluctuations. Given their increasing popularity and development of associated technologies, a range of load-velocity approaches have been investigated.

OBJECTIVE

This systematic review and individual participant data (IPD) meta-analysis sought to quantify the predictive validity of individualised load-velocity relationships for the purposes of 1RM prediction.

METHODS

In September 2022, a search of MEDLINE, SPORTDiscus, Web of Science and Scopus was conducted for published research, with Google Scholar, CORE and British Ethos also searched for unpublished research. Studies were eligible if they were written in English, and directly compared a measured and predicted 1RM using load-velocity relationships in the squat, bench press, deadlift, clean or snatch. IPD were obtained through requests to primary authors and through digitisation of in-text plots (e.g. Bland-Altman plots). Risk of bias was assessed using the Prediction model Risk Of Bias ASsessment Tool (PROBAST) and the review conducted in accordance with PRISMA-IPD guidelines and an a priori protocol. Absolute and scaled standard error of the estimates (SEE/SEE%) were calculated for two-stage aggregate analyses, with bootstrapping performed for sampling variances. Estimates were pooled using three-level hierarchical models with robust 95% confidence intervals (CIs). One-stage analyses were conducted with random intercepts to account for systematic differences across studies and prediction residuals calculated in the absolute scale (kg) and as a percentage of the measured 1RM. Moderator analyses were conducted by including a priori defined categorical variables as fixed effects.

RESULTS

One hundred and thirty-seven models from 26 studies were included with each identified as having low, unclear or high risk of bias. Twenty studies comprising 434 participants provided sufficient data for meta-analyses, with raw data obtained for 8 (32%) studies. Two-stage analyses identified moderate predictive validity [SEE% 9.8, 95% CI 7.4% to 12.2%, with moderator analyses demonstrating limited differences based on the number of loads (β2Loads:>2Loads = 0.006, 95% CI - 1.6 to 1.6%) or the use of individual or group data to determine 1RM velocity thresholds (βGroup:Individualised =  - 0.4, 95% CI - 1.9 to 1.0%)]. One-stage analyses identified that predictions tended to be overestimations (4.5, 95% CI 1.5 to 7.4 kg), which expressed as a percentage of measured 1RM was equal to 3.7 (95% CI 0.5 to 6.9% 1RM). Moderator analyses were consistent with those conducted for two-stage analyses.

CONCLUSIONS

Load-velocity relationships tend to overestimate 1RMs irrespective of the modelling approach selected. On the basis of the findings from this review, practitioners should incorporate direct assessment of 1RM wherever possible. However, load-velocity relationships may still prove useful for general monitoring purposes (e.g. assessing trends across a training cycle), by providing high-frequency estimates of 1RM when direct assessment may not be logistically feasible. Given limited differences in predictions across popular load-velocity approaches, it is recommended that practitioners opting to incorporate this practice select the modelling approach that best suits their practical requirements.

REGISTRATION

https://osf.io/agpfm/ .

Patient ratings in exercise therapy for the management of tendinopathy: a systematic review with meta-analysis

OBJECTIVE

To synthesise exercise therapy intervention data investigating patient rating outcomes for the management of tendinopathy.

DESIGN

A systematic review and meta-analysis of randomized controlled trials investigating exercise therapy interventions and reporting patient rating outcomes.

SETTING

Any setting in any country listed as very high on the human development index.

PARTICIPANTS

People with a diagnosis of any tendinopathy of any severity or duration.

INTERVENTIONS

Exercise therapy for the management of tendinopathy comprising five different therapy classes: 1) resistance; 2) plyometric; 3) vibration; 4) flexibility, and 5) movement pattern retraining modalities, were considered for inclusion.

MAIN OUTCOME MEASURES

Outcomes measuring patient rating of condition, including patient satisfaction and Global Rating of Change (GROC).

RESULTS

From a total of 124 exercise therapy studies, 34 (Achilles: 41%, rotator cuff: 32%, patellar: 15%, elbow: 9% and gluteal: 3%) provided sufficient information to be meta-analysed. The data were obtained across 48 treatment arms and 1246 participants. The pooled estimate for proportion of satisfaction was 0.63 [95%CrI: 0.53-0.73], and the pooled estimate for percentage of maximum GROC was 53 [95%CrI: 38-69%]. The proportion of patients reporting positive satisfaction and perception of change increased with longer follow-up periods from treatment onset.

CONCLUSION

Patient satisfaction and GROC appear similar and are ranked moderately high demonstrating that patients generally perceive exercise therapies positively. Further research including greater consistency in measurement tools is required to explore and where possible, identify patient- and exercise-related moderating factors that can be used to improve person-centred care.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO ID=CRD42020168187 CONTRIBUTION OF PAPER.

What are small, medium and large effect sizes for exercise treatments of tendinopathy? A systematic review and meta-analysis

Objective

To quantify and describe effect size distributions from exercise therapies across a range of tendinopathies and outcome domains to inform future research and clinical practice through conducting a systematic review with meta-analysis.

Design

Systematic review with meta-analysis exploring moderating effects and context-specific small, medium and large thresholds.

Eligibility criteria

Randomised and quasi-randomised controlled trials involving any persons with a diagnosis of rotator cuff, lateral elbow, patellar, Achilles or gluteal tendinopathy of any severity or duration.

Methods

Common databases, six trial registries and six grey literature databases were searched on 18 January 2021 (PROSPERO: CRD42020168187). Standardised mean difference (SMD_pre) effect sizes were used with Bayesian hierarchical meta-analysis models to calculate the 0.25 (small), 0.5 (medium) and 0.75 quantiles (large) and compare pooled means across potential moderators. Risk of bias was assessed with Cochrane's Risk of Bias tool.

Results

Data were obtained from 114 studies comprising 171 treatment arms 4104 participants. SMD_pre effect sizes were similar across tendinopathies but varied across outcome domains. Greater threshold values were obtained for self-reported measures of pain (small=0.5, medium=0.9 and large=1.4), disability (small=0.6, medium=1.0 and large=1.5) and function (small=0.6, medium=1.1 and large=1.8) and lower threshold values obtained for quality of life (small=-0.2, medium=0.3 and large=0.7) and objective measures of physical function (small=0.2, medium=0.4 and large=0.7). Potential moderating effects of assessment duration, exercise supervision and symptom duration were also identified, with greater pooled mean effect sizes estimated for longer assessment durations, supervised therapies and studies comprising patients with shorter symptom durations.

Conclusion

The effect size of exercise on tendinopathy is dependent on the type of outcome measure assessed. Threshold values presented here can be used to guide interpretation and assist with further research better establishing minimal important change.

Interpreting magnitude of change in strength and conditioning: Effect size selection, threshold values and Bayesian updating

The magnitude of change following strength and conditioning (S&C) training can be evaluated comparing effect sizes to thresholds. This study conducted a series of meta-analyses and compiled results to identify thresholds specific to S&C, and create prior distributions for Bayesian updating. Pre- and post-training data from S&C interventions were translated into standardised mean difference (SMD_pre) and percentage improvement (%Improve) effect sizes. Bayesian hierarchical meta-analysis models were conducted to compare effect sizes, develop prior distributions, and estimate 0.25-, 0.5-, and 0.75-quantiles to determine small, medium, and large thresholds, respectively. Data from 643 studies comprising 6574 effect sizes were included in the analyses. Large differences in distributions for both SMD_pre and %Improve were identified across outcome domains (strength, power, jump and sprint performance), with analyses of the tails of the distributions indicating potential large overestimations of SMD_pre values. Future evaluations of S&C training will be improved using Bayesian approaches featuring the information and priors developed in this study. To facilitate an uptake of Bayesian methods within S&C, an easily accessible tool employing intuitive Bayesian updating was created. It is recommended that the tool and specific thresholds be used instead of isolated effect size calculations and Cohen's generic values when evaluating S&C training.

Health technologies for the prevention and detection of falls in adult hospital inpatients: a scoping review

OBJECTIVE

The objective of this scoping review was to examine and map the evidence relating to the reporting and evaluation of technologies for the prevention and detection of falls in adult hospital inpatients.

INTRODUCTION

Falls are a common cause of accidental injury, leading to significant safety issues in hospitals globally, and resulting in substantial human and economic costs. Previous research has focused on community settings with less emphasis on hospital settings.

INCLUSION CRITERIA

Participants included adult inpatients, aged 18 years and over; the concept included the use of fall-prevention or fall-detection technologies; the context included any hospital ward setting.

METHODS

This scoping review was conducted according to JBI methodology for scoping reviews, guided by an a priori protocol. A wide selection of databases including MEDLINE, CINAHL, AMED, Embase, PEDro, Epistimonikos, and Science Direct were searched for records from inception to October 2019. Other sources included gray literature, trial registers, government health department websites, and websites of professional bodies. Only studies in the English language were included. A three-step search strategy was employed, with all records exported for subsequent title and abstract screening prior to full-text screening. Screening was performed by two independent reviewers and data extraction by one reviewer following agreement checks. Data are presented in narrative and tabular form.

RESULTS

Over 13,000 records were identified with 404 included in the scoping review: 336 reported on fall-prevention technologies, 51 targeted detection, and 17 concerned both. The largest contributions of studies came from the USA (n=185), Australia (n=65), the UK (n=36), and Canada (n=18). There was a variety of study designs including 77 prospective cohort studies, 33 before-after studies, and 35 systematic reviews; however, relatively few randomized controlled trials were conducted (n = 25). The majority of records reported on multifactorial and multicomponent technologies (n = 178), followed by fall detection devices (n = 86). Few studies reported on the following interventions in isolation: fall risk assessment (n = 6), environment design (n = 8), sitters (n = 5), rounding (n = 3), exercise (n = 3), medical/pharmaceutical (n = 2), physiotherapy (n = 1), and nutritional (n = 1). The majority (57%) of studies reported clinical effectiveness outcomes, with smaller numbers (14%) reporting feasibility and/or acceptability outcomes, or cost-effectiveness outcomes (5%).

CONCLUSIONS

This review has mapped the literature on fall-prevention and fall-detection technology and outcomes for adults in the hospital setting. Despite the volume of available literature, there remains a need for further high-quality research on fall-prevention and fall-detection technologies.

A Novel Approach to 1RM Prediction Using the Load-Velocity Profile: A Comparison of Models

The study aim was to compare different predictive models in one repetition maximum (1RM) estimation from load-velocity profile (LVP) data. Fourteen strength-trained men underwent initial 1RMs in the free-weight back squat, followed by two LVPs, over three sessions. Profiles were constructed via a combined method (jump squat (0 load, 30-60% 1RM) + back squat (70-100% 1RM)) or back squat only (0 load, 30-100% 1RM) in 10% increments. Quadratic and linear regression modeling was applied to the data to estimate 80% 1RM (kg) using 80% 1RM mean velocity identified in LVP one as the reference point, with load (kg), then extrapolated to predict 1RM. The 1RM prediction was based on LVP two data and analyzed via analysis of variance, effect size (g/ηp2), Pearson correlation coefficients (r), paired t-tests, standard error of the estimate (SEE), and limits of agreement (LOA). p < 0.05. All models reported systematic bias < 10 kg, r > 0.97, and SEE < 5 kg, however, all linear models were significantly different from measured 1RM (p = 0.015 <0.001). Significant differences were observed between quadratic and linear models for combined (p < 0.001; ηp2 = 0.90) and back squat (p = 0.004, ηp2 = 0.35) methods. Significant differences were observed between exercises when applying linear modeling (p < 0.001, ηp2 = 0.67-0.80), but not quadratic (p = 0.632-0.929, ηp2 = 0.001-0.18). Quadratic modeling employing the combined method rendered the greatest predictive validity. Practitioners should therefore utilize this method when looking to predict daily 1RMs as a means of load autoregulation.

Autoregulation in Resistance Training: Addressing the Inconsistencies

Autoregulation is a process that is used to manipulate training based primarily on the measurement of an individual's performance or their perceived capability to perform. Despite being established as a training framework since the 1940s, there has been limited systematic research investigating its broad utility. Instead, researchers have focused on disparate practices that can be considered specific examples of the broader autoregulation training framework. A primary limitation of previous research includes inconsistent use of key terminology (e.g., adaptation, readiness, fatigue, and response) and associated ambiguity of how to implement different autoregulation strategies. Crucially, this ambiguity in terminology and failure to provide a holistic overview of autoregulation limits the synthesis of existing research findings and their dissemination to practitioners working in both performance and health contexts. Therefore, the purpose of the current review was threefold: first, we provide a broad overview of various autoregulation strategies and their development in both research and practice whilst highlighting the inconsistencies in definitions and terminology that currently exist. Second, we present an overarching conceptual framework that can be used to generate operational definitions and contextualise autoregulation within broader training theory. Finally, we show how previous definitions of autoregulation fit within the proposed framework and provide specific examples of how common practices may be viewed, highlighting their individual subtleties.

Linear accelerator output variability

The Wellington Cancer Centre is equipped with two matched linear accelerators (Varian 2100CD) linear accelerators (identified as SN1027 and SN42). Each morning, before treatments commence, a radiation therapist carries out an output constancy check of the radiation output and every fortnight a physicist measures, in a phantom, the delivered radiation dose to check on the machine calibration. The daily output checks have been recorded into a database (Argus QA for Radiation Oncology) since August 1997 and in June 1998 the fortnightly calibration measurements were added. The information in the database, up to April 2003, has been analysed to consider the quality of the daily constancy checks as compared with the fortnightly calibration measurements and whether the data contains useful information on machine performance. After allowance for the effects of machine recalibration the fortnightly calibration measurements had an average standard deviation of 0.4% and the daily constancy checks 0.8%. The daily constancy checks had a greater number of large deviations than would be expected assuming a normal distribution and were not a good predictor of the need for a recalibration. The fortnightly calibration measurements with a much lower spread give a reliable indication of the need for a recalibration allowing the adoption of a +/- 1% tolerance. Over the period analysed one accelerator (SN42) was relatively stable with the output generally drifting between +/- 1% while the other (SN1027) had a consistent increase in the average output of about 2.5% per year.

Dosimetry of small electron fields shaped by lead

Electron radiotherapy fields are commonly used to treat superficial cancers. Field shaping can be achieved by placing lead on the patient surface to minimise the dose to surrounding areas. However, significant dosimetry changes under high density material edges for electron fields have been reported in the literature. This project evaluated the dosimetry of small dimension electron fields shaped with lead placed on the surface. Comparisons were made between circular lead cutouts placed on the skin and low melting point alloy cutouts placed in an applicator. Depth doses, profiles and output factors were measured using a diode detector in a water phantom. Film was also used to determine surface dose delivered when the lead cutouts were placed on the surface. Minimal differences were observed between the different setups for the depth dose curves, although significant differences were seen in the penumbra and the surface doses. The penumbra is smaller for the lead cutouts placed on the surface, however, significant dose increases at the edge of the field were observed for larger fields and energies; this may result in undesirable clinical effects.

Anti-oxidants-- a protective role in cardiovascular disease?

Established risk factors for cardiovascular disease (CVD), such as hypertension, smoking and diabetes mellitus, explain only some of the observed variation in clinical events. This has maintained interest in other nutritional and biochemical factors that might contribute to the underlying pathophysiology of CVD. All of these risk factors are associated with increased oxidative stress in the vessel wall, which may contribute to CVD by several mechanisms. Studies in animal models of CVD have suggested that natural and synthetic anti-oxidants can prevent the development of clinical end points. These observations have generated the hypothesis that anti-oxidant therapy might also prevent CVD in human populations. This has been supported by epidemiological studies showing a negative correlation between circulating concentrations or dietary intake of natural anti-oxidant vitamins and CVD event rate. Many studies have also demonstrated a beneficial effect of anti-oxidants on surrogate markers of CVD such as endothelial function and lipoprotein oxidation. However, the results of large prospective randomised controlled intervention trials, mostly involving vitamin E in patients at increased risk of CVD, have been disappointing and have failed to demonstrate the anticipated benefits. This paper will critically examine the evidence and try to offer some explanation for the apparent failure of animal and epidemiological data to translate into meaningful clinical benefits.