CHANGES IN MECHANICAL WORK AND JOINT CONTRIBUTIONS OF THE LOWER LIMB JOINTS DUE TO FATIGUE IN DISTANCE RUNNING

The purpose of this study was to investigate changes in work, and joint contributions by the lower limb joints in response to fatigue in distance running and to obtain insight into maintaining the running velocity. Fifteen male distance runners ran a 4000 m trial in even pace. Running motion and ground reaction force were collected each lap and two- imensional inverse dynamics were performed to calculate the lower limb joint torques, powers and work in the initial, middle and final stages of the trial. The joint contributions of the lower limb joints represented the ratio of the work of each joint to the total mechanical work. Results indicated that the mechanical work and joint contribution did not change significantly from the initial to the final stages of the trial. The joint with the largest contribution decreased the joint contribution from the middle to the final stage, although these changes varied runner by runner. It was concluded that the lower limb joints could compensate each other to maintain the total work output during the trial