Corpus: Flexor carpi radialis muscle
1. Definition
The flexor carpi radialis muscle belongs to the superficial layer of the forearm flexors.
2. Anatomy
2.1. Origin
The flexor carpi radialis originates from the medial epicondyle of the humerus — between the palmaris longus muscle and the pronator teres muscle — as well as from the antebrachial fascia.
2.2. Insertion
The muscle runs obliquely across the ulna distally and ends in a long tendon that goes to the lateral wrist, where it forms a small bony groove in the trapezium bone. It finally attaches to the second metacarpal bone and — with a smaller tendon part — to the third metacarpal bone. In the lower third of the forearm, the radial artery runs between the tendon of the flexor carpi radialis and the tendon of the brachioradialis muscle.
3. Innervation
The innervation of the flexor carpi radialis muscle is provided by the median nerve with fibers from the C5, C6, and C7 segments.
4. Function
The flexor carpi radialis muscle causes flexion (bending) of the wrist (palmar flexion) as well as radial abduction. It supports pronation with the elbow extended.