High Quality Content by WIKIPEDIA articles! A wheelchair trainer or wheelchair treadmill is an apparatus that allows a manual wheelchair user to simulate linear (translational) travel while remaining stationary in a manner similar to an ambulatory person walking or running on a treadmill or a cyclist pedaling a bicycle on a bicycle trainer. The rear wheelchair wheels are placed in contact with vertical or horizontal rollers which may also be attached to flywheels, mechanical resistance or braking mechanisms, motors and various speed and force sensors. Flywheels may be sized to provide a user of a certain mass with a rotational inertia equivalent to their translational (linear) inertia in order to more realistically approximate actual wheelchair propulsion.