Patent ID: 7922187

Claim:
An atrophy-reducing wheelchair comprising: first and second side frames, each side frame including structural members lying substantially in a corresponding plane, a front wheel bracket pivotally connected to one of the structural members, and a rear wheel mount formed in one or another of the structural members and defining a rear wheel axis, the rear wheel axis of the second side frame being substantially in registration with the rear wheel axis of the first side frame, and the second side frame being offset from the first side frame along the rear wheel axes, and at least one of the first and second side frames being modified to include a pivot defining a pivot axis substantially perpendicular to the plane of the corresponding side frame and offset from the rear wheel axis, and also defining horizontal and vertical axes substantially perpendicular to the pivot axis and a journal defining a journal axis substantially perpendicular to the plane of the corresponding side frame and offset from the pivot axis and from the rear wheel axis; a front wheel rotatably mounted to each front wheel bracket; a rear wheel rotatably mounted to each rear wheel mount, the front and rear wheels cooperating to support the side frames; first and second pivotally connected crossbars having upper and lower ends and together defining a plane substantially perpendicular to the first and second planes, the lower end of the first crossbar being pivotally connected to the second side frame and the upper end of the first crossbar carrying a first longitudinal bar lying substantially in the first plane and slidably connected to the first side frame, the lower end of the second crossbar being pivotally connected to the first side frame and an upper end of the second crossbar carrying a second longitudinal bar lying substantially in the second plane and slidably connected to the second side frame, the crossbars and longitudinal bars cooperating to permit motion of the first and second side frames between an open position in which the second side frame is offset from the first side frame by a seat width and a closed position in which the second side frame is offset from the first side frame by a collapsed width; a seat supported between the first and second longitudinal bars; and at least one linkage movably connected to the modified side frame at the pivot and the journal, the linkage operatively connecting a movable foot support to the rear wheel of the modified side frame, wherein rotation of the rear wheel drives the linkage to move the movable foot support in a substantially linear vertical oscillating motion.