Biceps brachii

Musculus biceps brachii

MuscularSuperficial musclesArmLeft and right

View left in 3D View right in 3D

What it is

Two-headed muscle on the front of the arm. The long head's tendon arises from the supraglenoid tubercle and arches through the shoulder joint into the intertubercular groove; the short head arises from the coracoid process. The united belly ends in a tendon on the radial tuberosity plus the bicipital aponeurosis fanning over the forearm flexors.

Function

The strongest supinator of the forearm and a powerful elbow flexor; weakly flexes the shoulder.

Size

About 30 cm from origin to insertion; belly ~4 cm wide.

Clinical note

Rupture of the long-head tendon gives a "Popeye" bulge; the biceps reflex tests the C5–C6 nerve roots.