DATASET FOR STUDY: Acute effects of radial extracorporeal shock wave therapy on upper trapezius muscle stiffness in healthy adults: A randomized controlled trial

Purpose: To determine whether a single session of radial extracorporeal shock wave therapy (rESWT) acutely reduces upper trapezius muscle stiffness in healthy adults. Methods: Forty healthy adults were randomized to rESWT (n = 20) or a no-treatment control condition (n = 20). Elastic modulus was assessed with shear wave elastography at proximal and distal upper trapezius sites before and immediately after 2,300 impulses delivered at 10 Hz and 2.0 bar, or an equivalent period of prone rest. Within-session repeatability was quantified using intraclass correlation coefficients (ICC), typical error (TE), and coefficient of variation (CV). Treatment effects were evaluated with a mixed analysis of variance. Results: Repeatability was good to excellent (ICC = 0.86–0.93), with TE of 1.0–1.1 kPa and CV of 10.6%–12.5%. There was a main effect of time (F(1, 38) = 5.015, p = 0.031, ηp² = 0.117), but the time × group interaction was not significant (F(1, 38) = 0.115, p = 0.736, ηp² = 0.003). The time × site (p = 0.058) and time × site × group interactions (p = 0.064) were also not significant. Conclusion: A single rESWT session did not produce an intervention-specific immediate reduction in upper trapezius stiffness. Small acute changes should be interpreted in relation to the method's absolute measurement error.