Abstract des Autors

Little information exists on how body weight (BW) support influences running biomechanics. The study aim was to determine how reducing BW by 50 percent-80 percent influences muscle activity while running at different speeds. Subjects (n = 7) ran at 100 percent, 115 percent, 125 percent of preferred speed at 100 percent, 50 percent, 40 percent, 30 percent, 20 percent of BW per speed. Average (AVG) electromyography of the rectified signal was compared (within subject design; 3-speeds × 5-BW, repeated measures ANOVAs; biceps femoris [BF], rectus femoris [RF], tibialis anterior [TA], gastrocnemius [GA]). RF, BF, and GA AVG were not influenced by BW-speed interaction (p > .05) and increased across speeds (p < .05). RF and GA AVG signal was reduced as BW was reduced (p < .05), but BF only tended to be different (p = .08). TA was influenced by BW-speed interaction (p < .05) with EMG decreasing across BW (p < .05) while increasing across speeds except at 100 percent BW. Overall, muscle activity increased with speed and decreased by BW reductions. Verf.-Referat