Effects of Joint Moments on Horizontal and Vertical Velocities of Body Mass Center during Jumping in Different Directions

Abstract

1The purpose of this study was to elucidate the effects of the lower limb joint moments on 2 the horizontal and vertical velocities of the body mass center during jumping in different 3 directions. Ten male university students performed forward, vertical, and backward jumps, 4 during which their jumping motion (150 Hz) and ground reaction force (600 Hz) were 5 collected. Induced acceleration analysis was performed to quantify the body mass center 6 velocity produced by each joint moment. In all jump conditions, the hip, knee, and ankle 7 joints exerted extension and plantarflexion moments, and most of vertical velocity of the 8 body mass center was produced by the ankle moment. Additionally, the knee moment Advance Publication by J-STAGE

Comparison of Translational Momentum and Mechanical Energy Produced by Lower Limb Muscles between Horizontal and Vertical Jumps – A Computer Simulation Study

“…For this purpose, HJ and VJ were simulated using a musculoskeletal system, and the produced momenta and work outputs of the lower limb muscles were estimated. The velocities of the body's center of mass at takeoff in VJ were almost equal to that of a previous experimental study (Suzuki et al, 2018), while the horizontal velocity was larger and the vertical velocity was smaller in HJ than those observed in the previous study. In that study, participants were asked to land on lines set 1 m forward from the initial position while jumping as high as possible in HJ, whereas in the present study HJ was optimized to obtain the maximum jump distance.…”

“…The developed force of HAM was larger in HJ, whereas that of REC was larger in VJ. Suzuki et al (2018) reported that the knee extension moment accelerates the body's center of mass backward in jumping, whereas the hip extension moment slightly accelerates it. The extension moment of hip joint was larger in HJ, and that of the knee joint was larger in VJ.…”

“…Fukashiro et al (2005) revealed the importance of leaning the trunk forward at the beginning of the push-off to increase the forward velocity of the body's center of mass in the countermovement jump. Suzuki et al (2018) reported that the ankle plantarflexion moments produced forward and vertical acceleration of the body's center of mass and that the direction of acceleration was affected by the body's posture. In the present study, the initial posture of HJ was rotated 25° forward from that of VJ.…”

“…The segmental and muscle-specific parameters were shown in Tables A1 and A2. Segmental lengths were determined based on experimental data from ten participants (Suzuki et al, 2018) and inertial parameters were estimated using body segment parameters for Japanese athletes (Ae, 1996). The moment arms were calculated from the coordinates of the origin, insertion, and via-points of the muscles derived from Delp (1990).…”

“…To jump higher or farther, it is important to obtain greater translational momentum in an appropriate direction at takeoff. Suzuki et al (2018) estimated the body's center of mass velocity produced by lower limb joint moments during jumping in different directions and reported that the knee extension moment produces backward velocity of the body's center of mass and that ankle plantarflexion moment produces forward velocity, regardless of jumping direction. In addition, Jones and Caldwell (2003) and Fukashiro et al (2005) reported that the peak knee extension moment was smaller in horizontal jumping than in vertical jumping.…”