Flexor carpi ulnaris originates at the medial epicondyle and flexes/adducts the wrist.
The flexor carpi ulnaris is a superficial muscle in the anterior compartment of the forearm. It plays a key role in flexing and adducting the wrist. It is the most medial of the superficial forearm flexors and forms the ulnar border of the forearm.
The flexor carpi ulnaris is located on the anteromedial aspect of the forearm. It runs from the medial epicondyle of the humerus and the ulna down to the pisiform bone and the base of the 5th metacarpal.
The muscle has two heads — humeral and ulnar — and a single tendon that inserts onto the carpal bones.
The flexor carpi ulnaris contributes to:
The muscle is innervated by the ulnar nerve (C7, C8, T1). It is the only superficial forearm flexor not innervated by the median nerve.
The flexor carpi ulnaris lies superficial to the flexor digitorum superficialis and overlies the ulnar artery and ulnar nerve in the distal forearm.
The tendon of the flexor carpi ulnaris is visible and palpable on the medial side of the wrist, just anterior to the ulnar head. It serves as an important anatomical landmark for locating the ulnar nerve and artery.
The muscle originates from the mesoderm of the paraxial somites during embryological limb bud development. Its innervation by the ulnar nerve reflects its medial derivation within the forearm flexor mass.
In some non-human primates, the flexor carpi ulnaris has a more prominent role in wrist flexion due to their arboreal locomotion. In humans, its function is less dominant but still important in precision tasks and grip stabilization.