Abstract: A wheel chair system including a pair of levers mounted to each side of an operator seated in the wheelchair, each lever having a handle which the operator can articulate between a position aligned with the levers and a position normal to the levers. The levers are each connected to a planetary gear system and a double ratchet assembly and are movable by the operator forwardly and rearwardly through an arc. Each double ratchet assembly is connected to two chains, one of which is driven when the lever is rotated in one direction and the other of which is driven when the ratchet is rotated in the opposite direction. The handles, levers, ratchets and gears are configured and interconnected such that when the operator moves the handles and levers through a rowing motion, the wheel chair is powered in a forward direction. The gear set can be chosen, and modified, to be compatible with the strength characteristics of the upper body musculature of the operator.