Brachioradialis

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Brachioradial muscle
Brachioradialis.png
Anterior view of muscles of the left forearm with Brachioradialis shown in blue.
Gray417 color.PNG
Cross-section through the middle of the forearm. (Brachioradialis labeled at center left, sixth from the top.)
Latinmusculus brachioradialis
Gray'ssubject #125 451
OriginLateral supracondylar ridge of the humerus
Insertion   Distal radius (Radial styloid process)
Arteryradial recurrent artery
Nerveradial nerve
ActionsFlexion of forearm
 
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Brachioradial muscle
Brachioradialis.png
Anterior view of muscles of the left forearm with Brachioradialis shown in blue.
Gray417 color.PNG
Cross-section through the middle of the forearm. (Brachioradialis labeled at center left, sixth from the top.)
Latinmusculus brachioradialis
Gray'ssubject #125 451
OriginLateral supracondylar ridge of the humerus
Insertion   Distal radius (Radial styloid process)
Arteryradial recurrent artery
Nerveradial nerve
ActionsFlexion of forearm

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.

Contents

Action

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.

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. [1] [2]

Innervation

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.)

Additional images

Left humerus. Anterior view.  
Bones of left forearm. Anterior aspect.  
Front of the left forearm. Superficial muscles.  
Posterior surface of the forearm. Superficial muscles.  
The radial artery.  
The radial and ulnar arteries.  
Ulnar and radial arteries. Deep view.  
Nerves of the left upper extremity.  
Brachioradialis  
Brachioradialis, lateral view  
Brachioradialis muscle  
Brachioradialis muscle  
Brachioradialis muscle  
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Brachioradialis muscle  
Brachioradialis muscle  
Brachioradialis muscle  
Brachioradialis muscle  
Brachioradialis muscle  
Brachioradialis muscle  
Brachioradialis muscle  
Brachioradialis muscle  
Brachioradialis muscle  
Brachioradialis muscle


 

References

  1. ^ Bowden, Bradley S. Bowden, Joan M. An Illustrated Atlas of Skeletal Muscles. 2nd ed. 2002
  2. ^ Saladin, Kenneth S. Anatomy & Physiology. 4th ed. 2007

External links