Using ultrasound elastography to assess non-invasive, non-pharmacological interventions for musculoskeletal stiffness: a systematic review and meta-analysis

Purpose: To evaluate the current evidence regarding the use of ultrasound elastography for assessing non-invasive, non-pharmacological interventions for eliciting changes in musculoskeletal stiffness. Methods: A systematic search of MEDLINE, CINAHL, EMBASE, and Web of Science databases was performed in accordance with Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Information on measurement and intervention procedures was extracted. Bias was assessed using Cochrane Risk of Bias or Risk of Bias In Non-randomised Studies of Interventions (ROBINS-I) tools for studies with true or quasi-experimental designs, respectively. Analyses were conducted for adequately powered subgroups based on intervention type, measurement site, and population assessed. Results: Twenty-one studies were included in the review. Overall risk of bias was low for true experimental studies and moderate for quasi-experimental studies. Subgroup analyses indicated a large overall effect for interventions involving manual physiotherapy and taping/splinting for reducing masseter muscle stiffness in patients with masticatory muscle disorders (g = 1.488, 95% CI = 0.320–2.655, p = 0.013). Analyses for other intervention types and patient groups were underpowered. Conclusion: Ultrasound elastography demonstrates clinical applicability for assessing non-invasive, non-pharmacological interventions for musculoskeletal stiffness. However, the comparative efficacy of these interventions for modulating tissue stiffness remains inconclusive.