Aging, injury and/or other pathologies of joints, especially weight bearing joints, contribute to changes in natural biomechanics. Deviations from optimal biomechanics lead to acceleration of the natural history of joint pathology and ultimately osteoarthritis. A Magnetic Vector Control System made up of an assembly of magnetic field sources can be disposed at or near a joint typically on or in adjacent bones of the joint, on one side of a first mechanical axis that creates a torque or moment about a second different axis of the joint, that intersects the first mechanical axis, to decrease the joint reactive force at the joint surface or equivalently substantially shift the first mechanical axis to a new or preferred position.