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 Start in a standing position with your feet hip width wide. Hold a dumbbell in each hand at your side. Step 2 Raise the dumbbells out to the side until they are shoulder height. Pull your arms together towards the center of your body. Step 3 raise the dumbbells over your head while maintaining an engaged core. Lower the dumbbells back down, out and back down to your side.