Fig. 1.

Experimental setup. A: an illustration of the KineReach setup showing a participant seated in front of a table with an inverted HD monitor that displayed the task on a mirrorized screen placed at chin level; this screen occluded direct view of the hands. Sensors placed on the hand and upper arm collected data used to compute orientation and location of the wrist, elbow, and shoulder joints. Each hand was supported on an air sled that produced continuous pressurized air to reduce the mechanical effects of friction and gravity. B: schematic of the unilateral reaching task showing movement of a cursor (representing the position of the hand) to the middle target (1 target presented per trial). Participants were asked to move the cursor to the target (appearing in 1 of 3 directions in a pseudorandom manner) within 1 s. The task consisted of 90 trials performed with each of the left and right hands separately. Visual feedback of the cursor was removed upon moving beyond the start circle.