The |biceps brachii| (two-headed arm muscle) consists of the long head and the short head. It extends from the shoulder to the elbow and is the main flexor of the |elbow joint|. When working with other nearby muscles, it can also move the shoulder, since its upper ends are attached to the |scapula| (shoulder blade). In addition it can twist the lower arm so that the palm faces outward, a movement called ~supination~. At the lower end, the biceps tapers into a flat, strong ~tendon~ that is firmly fixed to a bulge on the upper end of the |radius|. The biceps and the triceps work together to control the up and down movement of the forearm.
