Abstract des Autors

A study was conducted to investigate the relationship between the characteristics of torque production with special reference to eccentric and concentric muscle contraction and the structural and functional properties at the lower limb joints in the human kinetic chain. Ten male college athletes were tested with a isokinetic dynamometer (Biodex) for eccentric and concentric torques during extension and flexion at the hip and knee, and plantar flexion and dorsiflexion at the ankle (angular velocity: 30, 60, 120 deg/s). The peak eccentric and concentric torques were higher in the order hip, knee and ankle joints, as the size of each muscle acting on its joint increased. However, the rate of peak concentric to eccentric torque (CON/ECC, %) was higher at the ankle joint than at the hip and knee joints. They tended to increase in the order of angular velocity; 30, 60, 120 deg/s. These results suggest that the ankle joint is characterized by higher eccentric torque production. This characteristic is probably due to the fact that (1) the ankle joint is located at the end of the human kinetic chain and plays a role in transmitting the power to the ground effectively, (2) the muscle tendon complex acting at the ankle joint must have increased stiffness and tolerate great stretch loads to store and reuse the amount of elastic energy, (3) the hip and knee joints located at the center are the main sources of power supply. On the other hand, no significant correlations were observed among the torques at the hip, knee and ankle. These results suggest that torque production is independent at each of the lower limb joints, and is based on the structural and functional properties of each joint. These findings seem to be useful to clarifying the methods of strength and power training that can be adapted to the characteristics of torque production and the structural and functional properties of the hip, knee and ankle joints. Verf.-Referat