MUSCLES ENGAGED Abdominals The abdominal muscles (abs) provide movement and support to your core area. The deeper and closer to the spine the particular abdominal muscle is, the more effect over body posture it will have, and this often contributes significantly to a healthy back. Obliques Many people put a lot of focus on working their abs but forget their surrounding neighbors; the oblique muscles. Obliques serve as stabilizers, and are used in almost every physical activity. Exercising your obliques should be a very important part of your workout program. Exercise Instructions Step 1 Start on your back with one leg crossed over the other and the opposite arm held up beside your head. Step 2 Cross over as you crunch and try to touch your elbow to your knee fully contracting your abs at the top of the motion. Step 3 Slowly lower your body back down to the starting position while maintaining control throughout the entire range of motion.