MUSCLES ENGAGED Chest Strengthening the chest muscles will help you push things easily and effortlessly. The muscles in your chest help stabilize your shoulder joint, which reduces your vulnerability shoulder joint injuries. Working your chest muscles also has an aesthetic factor (body contouring). 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. Exercise Instructions Step 1 Start with your arms shoulder width apart, a neutral spine and your core engaged. Step 2 Slowly lower your body down to the floor making sure to keep you core engaged to avoid any drooping in your lower back. Step 3 Press your body back up to the starting position, keeping your back flat throughout the entire range of motion.