Abstract: An exercise and rehabilitation apparatus for exercising an extremity of a user. The apparatus includes a flywheel having a first side and a second side with a channel in the first side. The channel has a top edge near a planer surface of the first side. A lever, such as a pedal or handle, is adjustable in position and combined with an adjustment member. The adjustment member is movable within the channel between first and second positions. However, the adjustment member cannot be removed from the channel through a slot along the top edge. A locking pin, biased in an extended position, is combined with the adjustment member and is movable between the extended position and a retracted position. The flywheel includes a plurality of openings adapted to receive the locking pin in the extended position in order to secure the adjustment member at a particular location within the channel.