Strain - To wear out beyond a normal limit, often causing micro or tiny tears.
Subluxation - To partially dislocate.
Supinate - To turn, facing upward. (When you collect change at the tollbooth, you supinate your palm.)
Surgery - Medicine where physical deformity or disease is treated by an operative procedure.
Suture - Usually a synthetic line with minimal reaction in biological tissue. Commonly used are nylon, prolene and gut. Absorbable suture will dissolve over time (vicryl and chromic).
Syndrome - A set of symptoms that characterize a disorder or disease.
Synovial Membrane - A thin tissue that lines the capsule surrounding the joint.
Synovitis - Inflammation of a synovial membrane. Usually painful, particularly on motion and is characterized by a fluctuating swelling due to effusion within a synovial sac.