OBJECTIVE: To examine whether the increased failure rates in obstacle avoidance of patients with lower limb amputation can be understood on the basis of increased delay and/or decreased amplitudes of obstacle avoidance responses.METHODS: Subjects performed obstacle avoidance on a treadmill while EMG recordings were made of several major muscles of the leg.RESULTS: It was found that subjects with a lower limb amputation have delayed responses (e.g. delays of 20 ms for the Biceps Femoris) and have decreased response amplitudes (36-41% smaller). Furthermore, such changes were observed not only on the prosthetic side, but also on the sound side. The decreased amplitudes were associated with increased failure rates in the obstacle avoidance task.CONCLUSIONS: It is concluded that the bilaterally delayed and reduced responses in persons with a lower limb prosthesis reflect a basic reorganization within the central nervous system aimed at providing synchronized activity in both lower limbs, even though the peripheral deficit involves only one limb.SIGNIFICANCE: The present results on obstacle avoidance responses can be used to evaluate future prosthetic training involving obstacle crossings for amputee rehabilitation.
Adult Amputation