Begin on your hands and knees. Fully extend your right arm and left leg, being careful not to arch your back. Then bring your arm and leg to the center of your body, trying to touch your right elbow ...
Functionally, the biceps are key players in elbow flexion (bending the arm), forearm supination (rotating the forearm so the palm faces upward, like turning a doorknob or opening a jar), and shoulder ...