The influence of age on learning a locomotor task

Objective: Knowledge about locomotor task performance and learning in the elderly is important in optimizing rehabilitation strategies. The aim of this study was to evaluate differences between young and elderly subjects in the acquisition and performance of a precision locomotor task, with full and restricted vision. Methods: The subjects walked on a treadmill and had to step as low as possible over an obstacle, without touching it. They received acoustic warning and feedback signals, indicating obstacle appearance and foot clearance, respectively. Full vision was provided during the first two runs and became restricted during the third run. The number of obstacle hits and adaptations in foot clearance, leg muscle activity, range of motion of leg joints and swing phase duration were assessed. Results: With vision, the performance improved in both groups. Restricted vision reduced the task accuracy in both the young and the elderly. However, only the young subjects regained optimal foot clearance with practice. Conclusions: Elderly subjects rely more on visual control when acquiring and performing a precision locomotor task. We suggest that this is due to an impaired function of proprioceptive feedback mechanisms, which can replace visual information in young subjects. Significance: In the elderly, therapeutical attention should be directed towards optimizing the use of the remaining proprioceptive inputs.