Older Adults Exhibit an Impaired Ability to Predict Movement Accuracy Due to Greater Motor Output Variability

The ability to predict movement accuracy is an important feature of the human motor system because it is necessary to make subsequent adjustments for the accurate execution of motor tasks [1]. The ability to predict is influenced by efference copy, sensory feedback and motor output variability [2]. During goal-directed movements, older adults are less accurate compared with young adults. The impaired accuracy in older adults may be associated with an impaired ability to predict their performance. It is unknown whether older adults can predict goal-directed movements equally well as young adults. The purpose of this study, therefore, was to compare the predictive ability of young and older adults during goal-directed movements with the elbow and ankle joints. We hypothesized that older adults will exhibit an impaired ability to predict endpoint accuracy due to greater motor output variability.