Effect of Ultrasound Treatment on Recovery from Delayed Onset Muscle Soreness After Eccentric Muscle Contractions

PURPOSE: To examine the effect of continuous ultrasound treatment during recovery from delayed onset muscle soreness (DOMS) following eccentric muscle contractions. METHODS: Twenty non-trained collegiate men were recruited, and equally and randomly assigned to either ultrasound treatment (UG; 24.3±2.7 yrs, 176±6 cm, 71 ±7 kg) or placebo-control group (CG; 25±2 yrs, 177±4 cm, 73±3 kg). For inducing DOMS, subjects performed maximal eccentric contractions of elbow flexors using their nondominant arm. Each subject performed two sets of 25 repetitions in a standardized fashion on a custom made preacher curl machine. Fifteen minutes of continuous ultrasound (0.5 MHz, peak intensity 1.0 W/cm2) for UG and sham-ultrasound for CG were administered at 24, 48, 72 and 96 hours after exercise while the tested upper arms were completely submerged in the water maintained at 35°C. Maximum voluntary isometric contraction (822.9±155.7vs 929.7±240.2 N; UG vs CG at baseline), relaxed arm angle(RANG; 156±5° vs 152±4°; UG vs CG at baseline), and muscle soreness (SOR) by visual analog scale were assessed before and after the treatments. Blood samples were obtained to measure serum creatine kinase (CK: 126±41 vs 136±61 U/L; UG vs CG at baseline) and aspartate aminotransferase (AST: 16±6 vs 14±8 U/L; UG vs CG at baseline) at 24, 48, 72, and 96 hours after treatment. RESULTS: In all variables, there were no statistical differences in group by time interaction using one-way ANO VA with repeated measures. CK and AST were continuously increased up to 96 hrs (CK, 12,134±7,256 vs 12,804±6,603 U/L; AST, 121±84vs 147±165 U/L; UG vs CG) after exercise in both groups. In treatment group, however, SOR (4.8±2.7 vs 3.8±2.6 at 72, and 3.4±2.1 vs2.7±2.1 at 96; before vs after treatment) and RANG (143±7° vs 147±6° at 24, 143±7° vs 148±5° at 48, 145±7° vs 148±6° at 72, and 145±6° vs 149±6° at 96; before vs after treatment) were significantly different before and after each treatment using t-test (p < 0.05). CONCLUSIONS: Based on the results, water mediated ultrasound treatments employed in this study did not demonstrate any efficiencies in managing DOMS as well as other indicators of muscle damage.