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 ) was 57 % lower in the older population. For the instant at P , 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. [ABSTRACT FROM AUTHOR]