Fig. 1

Pediatric robotic kinesthesia task. White circles represent the location of robotic movement endpoints. Each of the three targets were separated by 12 cm. Black lines show the movement of the robotically moved passive arm. Grey lines show the movements performed by the active arm to mirror-match the movement of the robot. a Hand paths of an exemplar 10 year old female control, AIS, and PVI participants for six movements in a single direction. A 17 year old male participant with AIS makes larger initial direction errors (IDE) in comparison to the ideal (robotic) trajectory (dashed line). A 7 year old female participant with PVI also demonstrates greater angular deviations than the exemplar control. b Hand speed profiles associated with movement in one direction depict the speed of the robotically moved passive arm (black line) relative to movements of the participant (grey lines). The speed profile of the exemplar control indicates excellent matching of robot speed. The speed profile of the AIS participant indicates variable speed after the movement of the passive arm. A participant with PVI matches the speed of the robot, but moves much later when matching