Stefan Villiger

Manual Wheelchairs do not steer but the direction of travel is determined by different velocities of the rear wheels. To initiate a turn, users can either increase the speed on one side, or – far more effective – slow down on the other. In consequence, propelling a wheelchair forward in real-life always involves a component of working backwards and simultaneous compensation for the lost energy. Directional control is therefore a source of energy loss that contributes to the inefficiency of wheelchair propulsion, is a hazard for users’ health, and, above all, simply frustrating. Our steering-by-leaning system allows wheelchair users to control the direction of travel without braking but through a laterally tiltable backrest that doubles as a steering wheel. This simple mechanism more than doubled propulsion efficiency in the lab, facilitates easy one-handed propulsion and was found to offer a dynamic and fun experience of movement for users with diverse walking disabilities.