Patent ID: 8157710

Claim:
An apparatus for exercising muscles associated with a ball joint or ball joints of a human body, comprising: a circular revolving arc defining a central axis of revolution, said circular revolving arc being substantially radially symmetrically arranged around said central axis; a guide member circumferentially adjacent and supporting said circular revolving arc for revolution around said central axis; a rigid user interface member for exercising a ball joint of a human body, said rigid user interface member depending from said circular revolving arc, which user interface member has a first end which is positionable at a plurality of points along an arcuate path centered on said central axis, and has a second end with a user interface; apparatus providing adjustable resistance to movement of said user interface by a user; and wherein at least one of the central axis of said arcuate path intersects said ball joint, said guide member is an arcuate guide, said arcuate path and said guide member lie in spaced substantially parallel planes, and said user interface member comprises a rigid arm, a linkage is intermediate and forms part of an operative connection between said user interface and said apparatus providing adjustable resistance, said linkage being routed through a centering member proximate said central axis, and a linkage is intermediate and forms part of an operative connection between said user interface and said apparatus providing adjustable resistance, and said linkage is arranged and routed so as to maintain the same length when said user interface is repositioned along said arcuate path.