Myopathy refers to any disorder that can be attributed to pathological, biochemical or electrical changes occurring in muscle fibers or in the interstitial tissue of voluntary musculature, and in which there is no evidence that such changes are due to nervous system dysfunction. Many of the dystrophies have associated features that are not a result of the muscle weakness. In rehabilitation, the best way to group myopathic diseases is by functional limitation. In order to assess function adequately, the clinician must understand the functional demands of the individual patient relative to their particular lifestyle. The myopathic patient may have a functional disability as a result of decrease in strength and endurance, orthopedic deformity, cardiopulmonary dysfunction and/or cognitive impairment. The spectrum of rehabilitation interventions for the patient with muscle disease may include exercise and assistive devices. Myogenic stem cells from bone marrow are an area with future promise.