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. Equipment Used 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 in a push-up postion with one hand on top of the Bosu and the other hand on the floor. Make sure that your hips are up and that your core is engaged. Step 2 Perform a push-up and then transfer your hands across the Bosu so that you are in the same starting postion but on the other side of the Bosu. Step 3 Do another push-up, cross your hands over the Bosu again back to the original starting postion and repeat.