Individuals with high tetraplegia have lost motor and sensory function below the neck. This population is highly disabled and requires some method of assistance to accomplish activities of daily living. To date, rehabilitative interventions available in the clinic are limited and have not been designed to exploit residual volitional control. The goal of this study was to validate the presence of volitional control at the hand in individuals with high tetraplegia when the arm is supported against gravity with a vertical assist device. Any volitional control is pertinent to the development of rehabilitative interventions for high tetraplegia because it can be utilized to improve the overall performance and user acceptance of the device. The results from this study provide evidence toward the possibility of an individual with high tetraplegia being able to position their hand and generate forces volitionally in a functional workspace if the weight of their arm is supported by a vertical assist device.