Flexor carpi ulnaris

Flexor carpi ulnaris

The flexor carpi ulnaris is found on the anteromedial (inner palm-side) surface of the forearm. It originates from both the medial epicondyleProminent bump on distal medial side; attachment for forearm muscles (“funny bone”). of the humerusLong bone of the upper arm; articulates with scapula at shoulder and radius/ulna at elbow. and the olecranon/posterior border of the ulnaMedial forearm bone (pinky side); forms the elbow hinge with humerus.. It can be identified on the model as the most medialToward the midline of the body muscle in the superficialNear the surface of the body. forearm flexor group. It runs along the ulnar (pinky) side. Its tendon inserts on the pisiformPea-shaped carpal sitting on top of triquetral; palpable bump on wrist’s medial side., hook of the hamateHooked carpal on the pinky side of the distal row., and the baseA substance that accepts hydrogen ions (H⁺) or releases hydroxide ions (OH⁻). of the 5th metacarpal. Look for it tracking toward the wrist’s pinky side.

An everyday action using this muscle is holding a heavy grocery bag or briefcase with your palm up. Wrist flexion and ulnar deviation (bending the wrist toward the pinky) come into play. Overuse might occur during activities involving repetitive wrist flexion. This can happen while using a hammer or lifting weights with poor wrist alignment. It can also occur when pushing heavy carts. Such actions lead to strain or tendinitis on the ulnar side of the wrist.

Origin

Medial epicondyle of the humerus (humeral headRounded proximal end that fits into the acetabulum of the hip bone.)

Olecranon and posterior border of the ulna (ulnar head)

Insertion

Pisiform bone

Hook of the hamate

Base of the 5th metacarpal

Actions

Flexes and adducts the wrist (ulnar deviation)