When flexor carpi ulnaris muscles contract, anterior surfaces of metacarpal Vs and humerus' medial epicondyles move closer together. Flexor carpi ulnaris muscles indirectly flex, medially flex and medially extend ulnas. During forearm accelerations, flexor carpi ulnaris muscles medially extend elbow joints and flex wrist joints. While flexor carpi ulnaris muscles flex wrist joints, they also ulnarly flex wrist joints. When pitchers throw curves, metacarpal IVs lead wrist joints.
Flexor carpi ulnaris muscles are fourth superior-most of five flexor epicondyle muscles.
Palmaris Longus Palmaris longus muscles attach to palms' transverse ligaments and to humeral medial epicondyles. When palmaris longus muscles contract, palms and humerus' medial epicondyles move closer together. Palmaris longus muscles indirectly flex, medially flex and medially extend ulnas. Palmaris longus muscles flex metacarpals. During forearm accelerations, palmaris longus muscles medially extend elbow joints and flex wrist joints.