Pulsed ultrasound fails to diminish delayed-onset muscle soreness symptoms

We investigated the effects of pulsed ultrasound on swelling, muscle soreness perception, relaxed-elbow extension angle, and muscular strength. Eight sets of concentric and eccentric actions induced delayed-onset muscle soreness of the elbow flexors. Group 1 received 20% pulsed ultrasound treatments (1-MHz, 7 minutes, 1.5 W/ cm(2) temporal peak intensity) twice a day immediately after postexercise assessments and at 3, 24, 27, 48, 51, 72, and 75 hours postexercise. Group 2 received sham treatments immediately after postexercise assessments and at 3,27, 51, and 75 hours postexercise and true treatments of pulsed ultrasound at 24, 48, and 72 hours postexercise. Group 3 received sham treatments of no ultrasonic output immediately after postexercise assessments and at 3, 24, 27, 48, 51, 72, and 75 hours postexercise. Thirty-six college-age females. We recorded upper-arm circumference, perceived soreness, relaxed-elbow extension angle, and elbow-flexion strength before (pretest), immediately postexercise, and at 24, 48, 72, and 96 hours postexercise. We noted differences over time but no treatment effect between groups or interactions between time and group for upper-arm circumference, perceived soreness, relaxed-elbow extension angle, or elbow-flexion strength. Pulsed ultrasound as used in this study did not significantly diminish the effects of delayed-onset muscle soreness on soreness perception, swelling, relaxed-elbow extension angle, and strength.