In the spinal cord injured population, inactivity is wide-spread, and most causes of death in those with spinal cord injury can be improved by increasing physical activity. Current electric wheel-chairs exacerbate inactivity in this population by performing all the work required for transportation. The new openPAW device uses bio and environmental feedback (ie. current arm strength, weight, slope) from the wheelchair to alter how much power is mechanically provided to the wheels on each arm crank.