Therapeutic ultrasound in muscle injury induced by eccentric exercise: systematic review and meta-analysis of randomized clinical trials

The purpose of the study is to evaluate the effects of therapeutic ultrasound (TUS) on pain, muscle strength, range of motion (ROM), muscle edema, and creatine kinase level (CK) in individuals with exercise-induced muscle damage. The systematic review with meta-analysis was conducted. The search included the bases Cochrane CENTRAL, EMBASE, MEDLINE (via PubMed), and PEDro, from their beginning until December 2015. Randomized clinical trials comparing TUS with placebo or control groups, in individuals with eccentric exercise-induced muscle damage, were included. The outcome measure was pain, ROM, muscle strength, muscle edema, and CK. On meta-analysis, the outcome measure was pain and ROM at 24, 48, and 72 h. Of 274 articles found, 9 studies were included in the systematic review and 5 in the meta-analysis. As compared with the placebo or control groups, TUS did not produce significant changes in pain and ROM at 24, 48, and 72 h after muscle damage—pain 24 h (−0.66; 95% CI −1.65 to 0.33), pain 48 h (−0.11; 95% CI −0.92 to 0.70), pain 72 h (−0.17; 95% CI −1.14 to 0.80); and ROM with relaxed elbow at 24 h (0.09°; 95% CI −3.08 to 3.26), 48 h (−1.80°; 95% CI −4.50 to 0.90), and 72 h (−0.70°; 95% CI −3.96 to 2.55). It was concluded that TUS produced no significant effect on the variables analyzed after eccentric and concentric exercise-induced muscle damage.