The present disclosure describes a system for providing an assistive driving force to a wheelchair. The system comprises a power assist system which includes a motion sensing system that is configured to detect the motion of the power assist system, and hence of the wheelchair, and a power assist drive system that is configured to provide an assistive drive force. The system also comprises a sensor, such as may be embedded in a wearable wristband, that is configured to detect the motion of a users hand and that is in communication with the power assist system. The system may be configured to determine whether the wheelchair is being manually pushed based at least in part on the user motion, and to activate an assistive drive force in response to a manual push. The system may also be configured to determine whether the wheelchair is being manually braked based at least in part on the user motion, and to deactivate an assistive drive force in response to a manual brake.
