The effects of different exercise approaches on muscle mechanical properties, strength, and jump performance: a...

Whole-body vibration (WBV), strengthening, and aerobic exercises are widely used to improve muscle function and physical performance; however, their comparative effects on passive muscle mechanical properties remain uncertain. This randomised trial compared their effects on muscle stiffness, thickness, isokinetic strength, and horizontal jump performance in sedentary healthy women.

Forty-four women aged 18-40 years were randomised (1:1:1:1) to WBV, strengthening, aerobic exercise, or control; 40 were analysed (n = 10 per group). Exercise groups completed supervised sessions three times weekly for four weeks. Stiffness and thickness were assessed using shear wave elastography and B-mode ultrasonography, strength using isokinetic dynamometry, and horizontal jump distance. Imaging and strength assessors were blinded. Mixed-design ANOVA was the main analysis; supplementary post hoc analyses incorporated the corresponding baseline outcome and body mass, with alternative models used when ANCOVA assumptions were not satisfied.

Group × time interactions were not significant for stiffness or thickness (p = 0.092-0.595). Significant interactions were observed for all strength outcomes and horizontal jump performance (p = 0.002-0.016; partial η² = 0.248-0.339). Compared with control, adjusted values were higher for concentric hamstring strength in all exercise groups, eccentric quadriceps strength in the WBV and strengthening groups, eccentric hamstring strength in the WBV group, and horizontal jump performance in the WBV and strengthening groups (all p ≤ 0.022). No adjusted pairwise differences were detected among active interventions.

Four weeks of exercise produced outcome-specific responses without demonstrating modality-specific changes in passive muscle stiffness or thickness or superiority among active interventions.