MUSCLES ENGAGED Shoulders The shoulder is the most movable joint in the body. However, it is an unstable joint because of the range of motion allowed. This instability increases the likelihood of joint injury, often leading to a degenerative process in which tissues break down and no longer function well. Equipment Used Cable Machine The cable machine is a piece of equipment used in weight training or functional training. A wide variety of exercises can be performed using the apparatus. Exercise Instructions Step 1 Start with your feet slightly wider than shoulder width, a slight bend in your knees while holding the cable handle with your outside arm. Step 2 Raise the cable across your body and up to shoulder height. Step 3 Lower the cable back down to the starting position and repeat.