The orthopedic literature has clearly demonstrated that the physical stimulus of motion is essential for the maintenance of the structural and functional integrity of synovial joints. As a result of this information, rehabilitation with passive motion has become an extremely important part of the rehabilitation of synovial joints throughout the body, especially when there is limited range of motion. This same biological principle must be applied to the temporomandibular joint, especially when there is limitation in mandibular mobility. The effects of limited joint mobility, as well as passive motion, on the articular and extra-articular components of synovial joints is reviewed in detail. The clinical application of these principles in the management of temporomandibular disorders is emphasized.