The biceps brachii is a large muscle of the upper arm. Originally called “musculus”, it got its name from the Latin for mouse, referring to the arch of a mouse’s back. It then gave its name back to all other muscles. The biceps is considered generally representative of strength across a variety of cultures.
The biceps are a common source of pain in the front of the shoulder and occasionally the inside of the elbow. It is composed of two “heads” with slightly different attachments. The long head originates on the upper margin of the shoulder socket. The short head originates in the coracoid process on the front of the shoulder. Both heads proceed down the humerus, past the elbow, into the forearm and attach to the radius.
The actions of the biceps are complex. The primary function is to flex and rotate your forearm, moving it from pronation (palm down) to supination (palm up). It also flexes your arm at both the elbow and the shoulder and assists the rotator cuff in stabilizing your shoulder joint.
Trigger points in your biceps cause superficial pain in the front of your should