The locomotor system allows the individual to interact with his/her environment. The lower extremities in humans predominately allow ambulation. The upper extremities manipulate the environment via gross and fine motor tasks. The neurological system provides signals for movement and thought (in more advanced function). The musculoskeletal system carries out the actions. Even typing, talking and looking require adequate musculoskeletal function. The scope of musculoskeletal medicine is broad and includes investigation / assessment and treatment of abnormal function. This requires a good basic understanding of relevant anatomy, joint function and biomechanics. It is difficult if not impossible to understand the abnormal in MSK without knowing the normal.