Explosive movement in the older men: analysis and comparative study of vertical jump

Background Loss of power has been demonstrated to have severe functional consequences to perform physical daily living tasks in old age. Purpose This study aimed to assess how moment and velocity were affected for each joint of the lower limbs during squat jumping for older men in comparison with young adults. Methods Twenty-one healthy older men (74.5 +/- 4.6 years) and 22 young men (21.8 +/- 2.8 years) performed maximal squat jumps. Inverse dynamics procedure was used to compute the net joint power, moment and velocity produced at the hip, knee and ankle joints. Results and discussion Vertical jump height of the elderly was 64 % lower than the young adults. The maximal power of the body mass center (P (max) (bmc) ) was 57 % lower in the older population. For the instant at P (max) (bmc) , the vertical ground reaction force and the vertical velocity of the body mass center were 26 % and 35 % less in the older adults than in the young adults, respectively (p < 0.05; ES = -1.64 for vertical ground reaction force; p < 0.05; ES = -1.10). A lower value of the hip (-60 %), knee (-72 %) and ankle (-68 %) joint powers was observed in older adults. This was explained by both lower values of joint moments (-64, -57 and -61 % for the hip, knee and ankle, respectively) and angular velocities (-59, -49 and -52 % for the hip, knee and ankle, respectively). Conclusion This study showed a lower joint power when performing vertical jump. This smaller power resulted from both a lower moment and angular velocity produced at each joint.