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 (middle) Middle back muscles are very important as they help to support and strengthen the core muscles at the front of your body. Exercise Instructions Step 1 Start in a four point kneeling position on the floor. Make sure that your back is flat and your core is engaged. Step 2 Lift your leg and softly extend your knee out to your hip. Step 3 Bend your knee, return your leg back down to he ground and repeat.