Nonpharmacological Therapies for Musculoskeletal Injury in Military Personnel: A Systematic Review/Meta-Analysis
Authors: Talbot Laura A , Wu Lin , Morrell Christopher H , Bradley David F , Ramirez Vanessa J , Scallan Ross M , Zuber Pilar D , Enochs Kayla , Hillner Jesse , Fagan Mathias , Metter E Jeffrey 
Published: February 2024

ABSTRACT

Introduction
Musculoskeletal (MSK) injury is an inherent risk for military personnel that can potentially impact job performance, productivity, and military readiness. Evidence is needed to show the efficacy of nonpharmacological, self-managed therapies to reduce MSK symptoms at common injury sites that are feasible for use during expeditionary operations and home stations. This systematic review and meta-analysis identified, summarized, and synthesized available evidence from randomized and non-randomized trials on the effectiveness of self-managed, home-use therapies to improve pain, muscle strength, and physical performance in military personnel with MSK injuries, when compared to controls.

Methods
The electronic databases of MEDLINE ALL Ovid, Embase.com, Cochrane Library, Scopus, Clinicaltrial.gov, and CINAHL Complete via EBSCO were systematically searched for relevant reports published in English. Utilizing the Covidence platform and consistent with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, multiple reviewers, using pre-determined data fields, screened for eligibility, assessed risk of bias (RoB), and performed data extraction. Evaluation of treatment effectiveness was determined using multilevel mixed-effects meta-analysis.

Results
The database and register search yielded 1,643 reports that were screened for eligibility. After screening of titles/abstracts and full texts, 21 reports were identified for evidence synthesis. Of these, two reports were excluded and two described the same study, resulting in a final list of 18 studies (19 reports). For quality assessment, the overall RoB for the 18 studies was categorized as 33.3% low risk, 55.6% with some concerns, and 11.1% high risk. Across the five domains of bias, 70% of the reports were classified as low risk. This systematic review found that the differences in interventions, outcome measures, and design between the studies were associated with a substantial degree of heterogeneity (I2 = 60.74%), with a small overall improvement in outcomes of the interventions relative to their specific control (standard mean difference 0.28; 95% CI, 0.12 to 0.45). There were varying degrees of heterogeneity for individual body regions. This was due, in part, to a small number of studies per bodily location and differences in the study designs. For the neck/shoulder, heterogeneity was moderate, with the clearest positive effect being for physical performance outcomes via other medical devices. For the back, there was substantial heterogeneity between studies, with modest evidence that pain was favorably improved by other medical devices and exercise interventions. For the leg, one study showed a clear large effect for other medical devices (shockwave treatment) on pain with substantial heterogeneity. The best evidence for positive effects was for the knee, with mainly negligible heterogeneity and some benefits from bracing, electrotherapy, and exercise.

Conclusion
Evidence showed small beneficial effects in pain, strength, and physical performance by individual body regions for some interventions, compared to controls. The best evidence for a positive effect was for the knee. The findings suggest that some benefit may be obtained by including several treatments during deployment in austere environments and prolonged casualty care scenarios of military personnel with MSK injuries. Further research is warranted to better assess the potential benefits of using these treatments during deployments in austere environments as part of an individualized, multimodal approach for MSK injuries.