Development and Evaluation of a Gravity Compensated Training Environment for Robotic Rehabilitation of Post-Stroke Reaching

External support of the arm against gravity has a beneficial impact on reaching movements performed by moderately and severely impaired stroke survivors. Provision of scalable gravity compensation may therefore be an important component of robot-based upper limb rehabilitation. This study reports the development and initial evaluation of a scalable gravity-compensated training environment based on the haptic capabilities of the MACARM cable robot. The feasibility of end-point force compensation for gravity torques at the shoulder and elbow is evaluated for movements performed in a vertical plane. Our Progressive Support Training approach is described in detail and the initial results of testing with human subjects are reported.