Gravity support from a robotic exoskeleton increases spontaneous use of the nondominant upper extremity during a choice reaching task.

The objective was to determine whether gravity support for the left arm of right-handed participants would increase left arm use during a three-dimensional (3-D) reaching task in virtual reality. Twelve healthy control participants each completed 630 reaching movements broken into six blocks. The majority of targets were placed close to the midsagittal plane at three heights, and participants were free to use either limb when reaching for targets.