The biceps muscle has 2 heads, the long head and short head.
This muscle is responsible for bending the forearm back towards the upper arm so is involved in lifting and pulling movements. It also plays a part in supinating the forearm, turning the palms to face upwards or forwards.
The biceps muscles lie between the shoulder and the elbow. It is one of three muscles that make up the front (or anterior) part of the upper arm. It shares the space with the Brachialis muscle and the Coracobrachialis muscle.
The biceps muscle crosses the shoulder and the elbow, making it one of the few muscles that cross more than one joint.
This smaller muscle is located underneath the biceps brachii and on both sides. The brachialis assists with flexion of the elbow. One unique fact about this muscle is that it only becomes completely activated when the arm is being flexed but not actually moving.