Stand with your feet about shoulder-width apart, your knees and hips slightly bent, and your weight on your heels. With your upper arms pulled firmly to the side of your body, hold the bar with your hands placed just outside your shoulders. Begin with your elbows aligned just in front of your shoulders and slightly bent. Your upper arms should be parallel to the cable.
Contract your biceps, flex your elbows, and with your hands relaxed, begin to pull your lower arms out and up in front of your body. Pull your lower arms out and up in their natural angle from the elbow as far as they go without moving your upper arms. Hold, relax your hands, and continue to contract your biceps. Slowly lower your arms to their starting position. Repeat.