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. Quadriceps The quadriceps (quads) are a group of four muscles on the front of the thigh. They allow your knee to straighten and provide stability when standing. Your quads are the most important muscle group for maintaining the ability to stand and to walk independently. Equipment Used Weight Plate A weight plate is a single solid piece of metal without rotating parts. Weight plates typically range between 1lb and 55lb. A bumper plate is a weight plate that is coated in rubber so that it can be dropped on the floor safely during exercises like the deadlift, snatch and jerk. Bosu The BOSU balance trainer stands for "Both Sides Utilized" and is most often used for balance training, various athletic drills and aerobic activities. Exercise Instructions Step 1 Start on top of the underside of the Bosu with your feet shoulder width apart while holding the weight plate in front of your chest with both hands. Step 2 Lower your body down into a squatting position placing a majority of your body weight onto your heels. Lower your body until your elbows touch your knees. Step 3 Stand back up through your heels and press the plate completely over your head. Lower the weight plate back down to your chest and repeat.