Flexor carpi ulnaris

The flexor carpi ulnaris (Latin: musculus flexor carpi ulnaris) is a long fusiform-shaped superficial muscle of the upper limb that extends between the humerus, ulna, carpal and metacarpal bones. It is one of the wrist flexors, and it belongs to the anterior muscles of the forearm. The flexor carpi ulnaris is situated in the first (superficial) layer of the anterior forearm compartment. Like the pronator teres, this muscle is also composed of two heads - humeral and ulnar.

Origin

The humeral head of the flexor carpi ulnaris muscle originates from the medial epicondyle of the humerus. In contrast, the ulnar head arises from the olecranon and proximal posterior margin of the ulna.

Insertion

The flexor carpi ulnaris inserts on the pisiform and hamate bones and the base of the fifth metacarpal bone.

Action

The flexor carpi ulnaris muscle provides the flexion and adduction of the wrist at the wrist joint.

Innervation

The flexor carpi ulnaris is innervated by the ulnar nerve (C7 - T1) that arises from the brachial plexus.

Blood supply

The flexor carpi ulnaris muscle receives arterial blood supply from the branches of the posterior ulnar recurrent, inferior ulnar collateral and ulnar arteries. The first one is a branch of the ulnar artery, while the rest are branches of the brachial artery.