Enhanced performance of maximum vertical jump by arm movement / 体力科学

ABSTRACT

The effects of an arm lifting movement (ALM) on maximum vertical jumps with all but the ankle joints fixed (propelled only by plantar flexion) were studied in five subjects. ALM increased flight time, but did not alter maximum angular velocity of the ankle before takeoff. Holding 4kg dumbbells in their hands enhanced the effect of ALM on flight time. ALM increased the maximum force and the force at the onset of plantar flexion. Elbow angle recordings showed that both arms were accelerated before or around plantar flexion onset, and decelerated mainly after takeoff. In another series of experiments, we measured the vertical component of head and hand acceleration with accelerometers. ALM produced positive acceleration of the head after takeoff, which was related to negative acceleration of the hand. The results suggest that ALM increased flight time by enhancing plantar flexion torque under suppression of ankle angular velocity before takeoff. We discussed the relationship between this suppression and different acceleration between the arms and the body except the arms.