|Anterior view of muscles of the left forearm with Brachioradialis shown in blue.|
|Cross-section through the middle of the forearm. (Brachioradialis labeled at center left, sixth from the top.)|
|Gray's||subject #125 451|
|Origin||Lateral supracondylar ridge of the humerus|
|Insertion||Distal radius (Radial styloid process)|
|Artery||radial recurrent artery|
|Actions||Flexion of Elbow|
Brachioradialis is a muscle of the forearm that acts to flex the forearm at the elbow. It is also capable of both pronation and supination, depending on the position of the forearm. It is attached to the distal styloid process of the radius by way of the brachioradialis tendon, and to the lateral supracondylar ridge of the humerus.
Brachioradialis flexes the forearm at the elbow. When the forearm is pronated, the brachioradialis tends to supinate as it flexes. In a supinated position, it tends to pronate as it flexes. This also helps out the biceps of the arm.
The brachioradialis is a stronger elbow flexor when the forearm is in a midposition between supination and pronation at the radioulnar joint. When pronated, the brachioradialis is more active during elbow flexion since the biceps brachii is in a mechanical disadvantage.
With the insertion of the muscle so far from the fulcrum of the elbow, the brachioradialis does not generate as much force as the brachialis or the biceps. It is effective mainly when those muscles have already partially flexed at the elbow. The brachioradialis flexes the forearm at the elbow, especially when quick movement is required and when a weight is lifted during slow flexion of the forearm. The muscle is used to stabilize the elbow during rapid flexion and extension while in a midposition, such as in hammering. The brachioradialis is synergistic with the brachialis and biceps brachii; the triceps brachii and anconeus are antagonistic.
Despite the bulk of the muscle body being visible from the anterior aspect of the forearm, the brachioradialis is a posterior compartment muscle and consequently is innervated by the radial nerve. Of the muscles that receive innervation from the radial nerve, it is one of only four that receive input directly from the radial nerve. The other three are the triceps, anconeus, and extensor carpi radialis longus. (All other posterior compartment muscles that receive radial innervation are supplied by the deep branch of the radial nerve.)
- Bowden, Bradley S. Bowden, Joan M. An Illustrated Atlas of Skeletal Muscles. 2nd ed. 2002
- Saladin, Kenneth S. Anatomy & Physiology. 4th ed. 2007
- LUC brds
- UWASH brachioradialis
- SUNY Figs 07:01-09 - "Transverse section through the left arm just proximal to the elbow."
- SUNY Figs 07:03-07 - "Superficial muscles of the anterior (flexor) compartment of the left forearm."
- SUNY Figs 09:02-02 - "Superficial muscles of the posterior (extensor) compartment of the left forearm."
- lesson5musofpostforearm at The Anatomy Lesson by Wesley Norman (Georgetown University)