Flexor carpi radialis
Flexor radialis carpi
Flexor carpi radialis is a superficial muscle of the front of the forearm that bends the wrist and tilts the hand towards the thumb.
At a glance
- English
- Flexor carpi radialis
- Latin (TA2)
- Flexor radialis carpi
- System
- Muscle
- Region
- Upper limb
- Side
- Paired, left and right
About the flexor carpi radialis
Flexor carpi radialis belongs to the superficial flexor group on the front of the forearm. It lies between pronator teres on its lateral side and palmaris longus on its medial side, and its tendon is one of the most useful landmarks at the front of the wrist.
Like the other superficial flexors it starts from the common flexor tendon on the humeral medial epicondyle, with some fibres from the surrounding fascia. The fleshy belly runs obliquely down and outwards and becomes a tendon in the lower half of the forearm. At the wrist this tendon does not pass through the carpal tunnel proper. Instead it runs in its own split within the flexor retinaculum and then in a groove on the trapezium, reaching the palmar base of the second metacarpal, usually with a small slip to the third.
The muscle flexes the wrist and, with the radial extensors, abducts the hand. Together with flexor carpi ulnaris it gives straight flexion. It can also assist pronation and flexion at the elbow, although only weakly. It is supplied by the median nerve and receives blood from muscular branches of the radial and ulnar arteries.
At the front of the wrist its tendon is easy to see when the wrist is bent against resistance. The radial pulse is felt just lateral to it, and the median nerve lies just medial and slightly deep to it, which guides injections and surgical approaches. The tendon also leads surgeons to the scaphoid and the distal radius in the common volar approach. Its sheath can become inflamed where it runs over the trapezium, giving pain at the base of the thumb.
Attachments, action and supply
- Origin
- Humeral medial epicondyle by the common flexor tendon, and the surrounding deep fascia.
- Insertion
- Palmar base of the second metacarpal, often with a slip to the third.
- Action
- Flexes the wrist and abducts the hand; weakly assists pronation and elbow flexion.
- Nerve supply
- Median nerve (C6, C7).
- Blood supply
- Muscular branches of the radial and ulnar arteries.
Anthromica
See the flexor carpi radialis where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
