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 Dumbbells The dumbbell, a type of free weight, is a piece of equipment used in weight training. It can be used individually or in pairs (one for each hand). Dumbbells vary in weight from 3lbs. up to 150lbs. Exercise Instructions Step 1 Stand with your feet shoulder width apart, your back straight and hold the dumbbells in hand in front of your thighs. Step 2 Keep your shoulders back as you raise the dumbbells up in front of you. Step 3 Raise the dumbbells up to shoulder height and then lower them back to the starting position.