2019 Volume 17 Pages 13-24
The purpose of this study was to analyze the relationships between the joint power during the propulsion phase of the standing long jump and the maximum isokinetic strength of the lower limb joints. The subjects comprised 11 male athletes specialized in different sport events. The isokinetic strengths of the extensor muscles at the ankle, knee, and hip joints at two angular velocities were evaluated by dynamometry. Joint powers during the propulsion phase of the standing long jump were calculated with two-dimensional coordinate data (50 Hz) and ground reaction force data (500 Hz). Knee and hip joint peak power during the propulsion phase, normalized by the body mass, highly and significantly correlated with the jump distance (knee: r=0.767, p<0.01, hip: r=0.723, p<0.05). Isokinetic extensor strength of the ankle, knee, and hip joints, normalized by the body mass, did not correlate with peak power during the propulsion phase at the corresponding joint. Additionally, the isokinetic extensor strength did not correlate with the jump distance, with one exception. Although the jump distance depended on lower limb joint power during the propulsion phase, power was not directly modulated by the isokinetic strength. This phenomenon might be derived from the use of strategies that enhance lower limb power, which include a counter-movement and the coupling of an arm swing to the lower limb motion.