Flexor carpi radialis
Arising from the common origin the fleshy belly lies distal to pronator teres. In the middle of the forearm the flesh gives way to a flattened tendon which becomes rounded at the wrist, where it first perforates the flexor retinaculum, and then lies in the groove of the trapezium. It passes deep to the tendon of flexor pollicis longus and is inserted into the bases of the first and second metacarpals (symmetrically with extensors longus and brevis). Quite frequently it gives a slip of insertion into the scaphoid bone. The absence of fleshy fibers distinguishes the tendon above the wrist from that of flexor pollicis longus, which is ‘feathered’ by fleshy fibers joining it from the radial side. The tendon is a prominent landmark towards the radial side of the front of the wrist. The radial artery lies lateral to the tendon and the median nerve (and the tendon of palmaris longus, if present) medial to it.
Nerve supply of flexor carpi radialis:
By the median nerve (C6 and 7).
Action of flexor carpi radialis:
The muscle is a flexor and radial abductor of the wrist.