The influence of haptic feedback on hand movement regularity in elderly adults

Eight elderly adults and eight young adults were requested to perform circular movements with the hand through a commercial haptic platform, under different conditions in an ecological setting: with visual feedback, and with a force field produced by the machine. Measures of kinematics and movement regularity (maximum velocity, duration, mean square jerk, and its normalized form) were captured to determine the effect of these feedbacks on hand kinematics. In the elderly group, regularity was lower when haptic feedback was given in combination with visual feedback as compared to providing haptic feedback alone. This effect appeared also in the group of young adults, and outlines the possibility that the ability to integrate different feedbacks may need more time to be learned, even if the feedbacks are generated to facilitate movements.