The application is directed to devices and methods where one or more magnetic or magnetizable implants provides therapeutic benefits to a patient. The implant may be useful for expanding the range of motion of joints or dynamically providing different responses to changing conditions in the body where the implant is placed. An electromagnet is placed on or in a bone on one side of a joint, and another electromagnet or magnetically active material is placed on or in a bone on the opposing side of the joint. The electromagnet may be continuously energized to relieve pressure in the joint space, or may be energized in response to forces applied to the joint.