Brachioradialis
Pronuncation | bray-kee-oh-ray-dee-AL-iss |
Derivation | Its attachments on the upper arm (brachio) and the radius. |
Origin | A short line on the lateral edge of the humerus. |
Insertion | The proximal end of the radius on its lateral side. |
Action | Bends forearm at elbow. |
The upper end of brachioradialis is most easily seen from the lateral side, as it emerges from between the lateral head of triceps and brachialis.
From here, it wraps around like a ribbon to the front of the arm and drops to the base of the radius.
When brachioradialis is tensed it pops up well above the rest of the forearm, creating a prominent ridge from the lateral side of the upper arm to halfway down the radius. This is true whether the forearm is pronated or supinated.
This is the only flexor on the forearm whose origin is on the lateral epicondyle of the humerus. (The rest attach to the medial epicondyle.)