The flexor carpi radialis and flexor carpi ulnaris contribute much of the muscle mass on the inner front side of the forearm.

Origin

The flexor carpi radialis and flexor carpi ulnaris have a common tendon for attachment on the inner condyle of the humerus at the upper end.

Insertion

The ulnaris inserts on the fifth metacarpal bone.

Function

Flexion and adduction (ulna flexion) of the wrist. It is mainly a flexor of the wrist and stabilizer of the elbow joint.

Wrist Curl (Wrist Flexion)

Ulna Flexion