The biceps in made of two muscles (hence the "bi" at the beginning word). The muscle runs from the shoulder and to just below the elbow. Its main function it to bend (flex) the elbow. It also rotates the fore arm bringing the palm up - this action is also known as supination.
Looking to tone your biceps? Try the Hammer Curl, but do note this exercise doesn't fully work the supination motion of the bicep since the palm is not fully rotated up toward the ceiling.
