Interlimb Transfer of Load Compensation during Single-joint Movements

Previous studies have investigated interlimb transfer of adaptation to visuomotor rotations, viscous curl-fields, as well as for ball catching and other complex tasks. We have recently revealed a nondominant arm advantage for load compensation responses. We now examine whether this short-latency response can be modified by prior opposite arm experience. Two subject groups, LR and RL, each comprising six right-handed subjects, experienced unpredictable loading during single joint speed constrained 20° elbow flexion. Each group first performed using either the left (LR) or right (RL) arm, followed by opposite arm performance. In order to assess transfer, we compared the same side arm movements (either right or left) following opposite arm performance to those made prior to opposite arm performance (Naïve). Our preliminary results indicate interlimb transfer, only from the nondominant to the dominant arm. Under näve conditions, nondominant arm responses are substantially more efficient, which may preclude improvement and thus limit the effects of opposite arm training. These results indicate that feedforward modifications of feedback based responses can transfer across the limbs, and thus, that such adjustments are not effector-specific.