MUSCLES ENGAGED Glutes Gluteal Muscles (Glutes) are one of the strongest muscles in the body and are the connecting point between your legs and back muscles. Glutes are used in a variety of actions from moving the leg to extending and rotating the hip, as well as extending and rotating the trunk of the body. Back (lower) The lower back is often not trained because it is not visible in the mirror. If you have weak lower back muscles, there is nothing to help pull back against the spine, putting you at risk of developing poor posture (hunched over). Weak lower back muscles can also lead to lower back pain. 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 position on the Bosu. Make sure that your wrists are directly below your shoulders and your core is engaged. Step 2 Keeping your back straight, lift your leg and contract your buttocks at the top of the motion. Do not let your lower back sag and hips disengage when you raise your leg. Step 3 Lower your leg, alternate and repeat the exercise.