Supinator Pronator Teres Pronator Quadratus

MusclesOriginInsertion Biceps BrachiiCoracoid process and tubercle above glenoid cavity of scapula Radial tuberosity of radius DeltoidAcromion process, spine of scapula, and clavicle Deltoid tuberosity of humerus BrachialisAnterior shaft of humerusCoronoid process of ulna SupinatorLateral epicondyle of humerus and crest of ulna Lateral surface of radius Pronator teresMedial epicondyle of humerus and coronoid process of ulna Lateral surface of radius BrachioradialisDistal lateral end of humerusLateral surface of radius above styloid process Extensor carpi radialis longusDistal end of humerusBase of second metacarpal Flexor carpi radialisMedial epicondyle of humerusBase of second and third metacarpals Palmaris longusMedil epicondyle of humerusFascia of palm Flexor carpi ulnarisMedial epicondyle of humerus and olecranon process Carpal and metacarpal bones Pronator quadratusAnterior distal end of ulnaAnterior distal end of radius Extensor carpi radialis brevisLateral epicondyle of humerusBase of second and third metacarpals Extensor digitorumLateral epicondyle of humerusPosterior surface of phalanges in fingers 2-5

MusclesAction Biceps BrachiiFlexes forearm at elbow and rotates hand laterally DeltoidAbducts arm, extends or flexes humerus BrachialisFlexes forearm at elbow SupinatorRotates forearm laterally Pronator TeresRotates forearm medially BrachioradialisFlexes forearm at elbow Extensor Carpi Radialis LongusExtends wrist and abducts hand Flexor Carpi RadialisFlexes and abducts wrist Palmaris LongusFlexes wrist Flexor Carpi UlnarisFlexes and abducts wrist Pronator QuadratusRotates forearm medially Extensor Carpi Radialis BrevisExtends wrist and abducts hand Extensor DigitorumExtends fingers