The biceps brachii muscle, usually just referred to as the biceps,is a superficial muscle located on the anterior arm. Remember, superficial means on or close to the skin or surface of an organ. You're familiar with this muscle as the one most people think they are flexing when they want to show off their arm muscles! Little do they know, right? Remember that it is the joint that does the flexing.As we mentioned earlier, the biceps muscle gets its name from the fact that it has two heads bi means two, and ceps means head and that each head of the muscle originates in a different place.The muscle fibers converge and have one point of insertion.An important distinction of the biceps is that, although it is the biggest muscle of the anterior arm, the biceps doesn't attach anywhere on the arm! You can see the shape and location of the biceps in Figure 18-7.
In addition to its role as an elbow flexor, the biceps also is a player in flexion of the shoulder joint together with the anterior deltoid, pectoralis major, and the coracobrachialis coco-brake which you learned about previously. The biceps works as an antagonist to the triceps brachii muscle group at both the shoulder and elbow joints. You'll learn about the triceps in the extensor group of muscles.