Effects of age and timing of augmented feedback on learning muscle relaxation while performing a gross motor task.

Objective: To examine the combined effect of age and timing of augmented feedback on learning muscle relaxation. Performing a gross motor task, subjects had to lower their trapezius muscle activity using the electromyographic signal as visual myofeedback.

Design: Healthy subjects (16 young adults: 20-35 yrs; and 16 older adults: 55-70 yrs) were randomly assigned to one of two timing conditions of myofeedback: concurrent (feedback was provided immediately during the trial) and terminal (feedback was provided delayed after the trial) condition.

Results: The results indicated that young adults had a higher level of motor performance (i.e., lower muscle activity) compared with older adults when myofeedback was provided. These effects persisted during short- (after 10 mins) and long-term retention (after 1 wk) when no myofeedback was provided. In contrast to young adults, older adults did not improve their performance throughout the experiment. There were no interactions of age with the timing conditions of myofeedback during acquisition and retention.

Conclusions: Either timing condition of augmented feedback was equally helpful to young adults, whereas neither was helpful for older adults in learning muscle relaxation.