A wheelchair configured to impart motion on one or more lower extremities of a user to inhibit inelasticity in joints of one or more lower extremities as a result of extended immobility, and to promote a more natural alignment of one or more upper extremities of the user during manipulation of the wheelchair. The wheelchair includes a seat and a backrest, at least two ground-engaging wheels, a hand mechanism assembly including a hand grip on each side of the wheelchair, and a foot mechanism assembly including a footrest on each of the wheelchair. When a force is applied to one of the hand grips, the wheels rotate for locomotion, and the foot mechanism assembly is actuated, causing the foot rest on the opposite side from the hand grip to move in an arced path, and vice versa, thereby imparting contralateral locomotion.

A wheelchair including a wheelchair propulsion system adapted to independently operate each of a pair of drive wheels by corresponding independent manual rotation of a pair of cranks.

A manual wheelchair including a collapsible frame having a first lateral member that is connected to first and second braces at their respective first ends. A drive wheel axel extends along a first axis of rotation and engages a drive wheel, the first brace, and a portion of a transmission. A push rim axel extends along a second axis of rotation and engages a push rim wheel, the second brace, and a portion of the transmission, which transmits rotation of the push rim to rotation of the drive wheel. The collapsible frame additionally includes a second lateral member that is connected to the first and second braces as their respective second ends. The first and second braces are configured to release the second lateral member to collapse the manual wheelchair.

A manual wheelchair including a collapsible frame having a first lateral member that is connected to first and second braces at their respective first ends. A drive wheel axel extends along a first axis of rotation and engages a drive wheel, the first brace, and a portion of a transmission. A push rim axel extends along a second axis of rotation and engages a push rim wheel, the second brace, and a portion of the transmission, which transmits rotation of the push rim to rotation of the drive wheel. The collapsible frame additionally includes a second lateral member that is connected to the first and second braces as their respective second ends. The first and second braces are configured to release the second lateral member to collapse the manual wheelchair.

A wheelchair having a frame and a drive wheel coupled to the frame. The drive wheel rotates relative to the frame about a first axis of rotation. A first push rim is coupled to the frame. The first push rim rotates relative to the frame about a second axis of rotation that extends substantially parallel to the first axis of rotation. A second push rim is coupled to the frame. The second push rim rotates relative to the frame about a third axis of rotation that extends substantially parallel to the first axis of rotation. A transmission transmits rotation of each of the first and second push rims to the drive wheel. Movement of the first push rim by a first arc length causes the drive wheel to rotate by a first angular displacement, and movement of the second push rim by the first arc length causes the drive wheel to rotate by a second angular displacement that is greater than the first angular displacement.