Abstract
Precision grasping is a highly prevalent everyday manual action. Previous studies have demonstrated that precision grasping is highly accurate and sensitive to object size. An outstanding question is whether the motor plan that guides these actions is hand-specific? Or, alternatively, can the same motor plan guide another body part that is less experienced in reaching and grasping in humans, such as the foot? We tested the kinematics of hand- and foot- grasping of blocks of different sizes in typically developed individuals. We measured the maximum grip aperture (MGA) and velocity as the hand and foot pre-shaped to grasp the blocks. Consistent with hand grasping, the maximum grip aperture of foot grasping linearly increases with block size, reflecting common preshaping mechanisms based on object size. In addition, the temporal velocity profile is similar across the hand and foot. Taken together, these findings potentially indicate a single neural mechanism that drives grasping behavior across body parts.