Quantification of Goal-Directed Stepping Behavior Under Two Limb Choice Conditions in Neurotypical Adults: A Preliminary Investigation

During reaching, arm choice depends on handedness, success, and effort; however, whether these factors influence leg choice for goal-directed stepping is still unknown. We aimed to quantify the kinematics and behavioral patterns of leg choice and to explore whether success and/or effort influence leg choice during goal-directed stepping under two <i>Choice</i> conditions in 20 right-leg dominant neurotypical adults. We adapted the classic center-out target array; participants stepped to pre-cued targets with an emphasis on accuracy without time constraints. The first set of trials was always <i>Free</i> for which either leg could be chosen. The second set of trials was verbally <i>Constrained</i> for which there was no choice as only the left non-dominant leg was to be used. We separately compared success, effort, and subjective difficulty between <i>Free</i> and <i>Constrained</i> trials for left and right target regions. In <i>Free</i>, participants uniformly selected the limb ipsilateral to the target. While success and subjective difficulty were not influenced by <i>Choice</i>, effort varied depending on <i>Choice.</i> Our preliminary findings suggest that during goal-directed stepping, leg choice depends on effort and may be independent of leg dominance and subjective difficulty, while the difficulty of the <i>Constrained Choice</i> condition can improve success independent of leg used.