Disturbances in the structure and function of the skeletal system. The musculoskeletal system provides a rigid structural frame that permits locomotion through muscle action and aids in the functioning of the other organ systems. It also houses blood-forming marrow tissue and stores calcium, phosphorus, magnesium, and a variety of other ionic species. Bone is unique among the tissues of the body in that it responds to injury by re-forming itself identically over time, without scarring.