The Impact of Age and Physical Activity Level on Manual Aiming Performance

Older adults traditionally adapt their discrete aiming movements, thereby travelling a larger proportion of the movement under closed-loop control. As the beneficial impact of a physically active lifestyle in old age has been described for several aspects of motor control, we compared the aiming performance of young controls to active and sedentary older adults. To additionally determine the contribution of visual feedback, aiming movements were executed with and without saccades. Results showed only sedentary older adults adopted the typical movement changes, highlighting the impact of a physically active lifestyle on manual aiming in old age. In an attempt to reveal the mechanism underlying the movement changes, evidence for an age-related decline in force control was found, which in turn resulted in an adapted aiming strategy. Finally, prohibiting saccades did not affect older adults’ performance to a greater extent, suggesting they do not rely more on visual feedback than young controls. Keywords: aging, physical activity, manual aiming, eye movement