Stand with your feet about shoulder-width apart, your knees and hips slightly bent, and your weight on your heels. Place one hand on your hip. With your other upper arm pulled firmly to the side of your body, hold the grip with your hand placed just outside your shoulder. Begin with your elbow aligned just in front of your shoulder and slightly bent. Your upper arm should be parallel to the cable.
Contract your biceps, flex your elbow, and with your hand relaxed, begin to pull your lower arm out and up in front of your body. Pull your lower arm out and up in its natural angle from the elbow as far as it goes without moving your upper arm. Hold, relax your hand, and continue to contract your biceps. Slowly lower your arm to its starting position. Repeat.