The purpose of this study was to elucidate the difference between trampoline and rebound jumps during the down phase. Electromyography of the lower extremity muscles, assessment of motion using a highspeed camera, and plantar pressure measurement were simultaneously performed during jumping. Both jump phases were divided into the first half (“down phase”) and second half (“upward phase”). In the trampoline jump, both the knee and hip joints were observed to extend and the foot segment was observed at a positive angle during the down phase. In the rebound jump, both the knee and hip joints were flexed and the foot segment was at a negative angle during the same phase. Plantar pressure of the heel was significantly higher in the trampoline jump than in the rebound jump. The trampoline and rebound jumps required two different actions in the down phase because the former jump pushed the trampoline bed down by the heels, and the latter one absorbed the source of impact.
