Physical Therapies for Delayed-Onset Muscle Soreness: An Umbrella and Mapping Systematic Review with Meta-meta-analysis.

BACKGROUND

Delayed-onset muscle soreness commonly arises from intense and unaccustomed physical exercise, leading to reduced muscle strength, increased pain and inflammation. A number of systematic reviews evaluating physiotherapeutic treatments for delayed-onset muscle soreness have been published since the 1990s. However, these systematic reviews frequently yield conflicting findings, further impeding clinical practice.

OBJECTIVES

The primary aim of this study was to summarise the effectiveness of physiotherapy interventions in alleviating delayed-onset muscle soreness through an umbrella review. Additionally, we evaluated the risk of bias in systematic reviews, synthesised their findings, and categorised the evidence strength to provide practical insights for clinicians and researchers.

METHODS

An umbrella review with a meta-meta-analysis was conducted. MEDLINE, Embase, Cochrane Database of Systematic Reviews, CINAHL, PEDro and Epistemonikos were searched from 1998 to February 2024. Systematic reviews of randomised controlled trials of any treatments used post-exercise by physiotherapists to reduce delayed-onset muscle soreness in healthy adults, regardless of their physical activity, were eligible. A MeaSurement Tool to Assess systematic Reviews-2 (AMSTAR-2) was used to evaluate the methodological quality of the included systematic reviews. Corrected covered areas were calculated to address the overlap of primary trials in the included systematic reviews. An evidence map was created to categorise and visualise the effects of interventions using a multi-dimensional approach, based on the effect size and strength of evidence (Class I-V), i.e. the number of cases, Hedges' g, p-value, heterogeneity, Egger's test and excess of significance bias test.

RESULTS

Twenty-nine systematic reviews with 863 unique randomised controlled trials, addressing 24 distinct physiotherapeutic treatments, met the inclusion criteria. Seventeen systematic reviews were of critically low methodological quality, with only two rated as high quality. The evidence map suggests significant effects in pain reduction immediately post-exercise for contrast therapy (Class II), cooling therapy and cryostimulation (Class IV); 24 h: massage therapy (Class III) and cooling therapy, contrast therapy, electrical stimulation, cryostimulation, phototherapy, heat therapy (Class IV); 48 h: compression, contrast therapy, kinesiotaping and cryostimulation (Class III) and cooling therapy, massage, phototherapy, heat therapy (Class IV); 72 h: kinesiotaping (Class III) and contrast therapy, cooling therapy, massage, phototherapy, vibration (Class IV); 96 h: compression, phototherapy, and contrast therapy (Class IV). The effect sizes (Hedges' g) ranged from 0.36 (95% confidence interval 0.46, 3.18) for cooling therapy to 1.82 (95% confidence interval 0.46, 3.18) for heat therapy indicating small and large effects, respectively.

CONCLUSIONS

There is a large body of evidence from predominantly low-quality systematic reviews of randomised controlled trials evaluating the effectiveness of physiotherapeutic treatments for delayed-onset muscle soreness. There is some strong evidence to support the effectiveness of cooling therapy, cryostimulation, contrast therapy, massage, phototherapy and kinesiotaping at various follow-up intervals, whereas evidence for stretching, exercises and electrical stimulation is weak. Uncertainties, heterogeneity and weaknesses of the available evidence partially limit the applicability and generalisability of the findings.

CLINICAL TRIAL REGISTRATION

PROSPERO registration number CRD42024485501 ( https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024485501 ).