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. Equipment Used Pull Up Bar A pull-up bar is a straight steel bar that mounts on a wall, door frame, squat rack or cable machine. It is one of oldest and most effective strength tools and is used to target the latissimus dorsi muscle (lats) along with the rhomboids, shoulders and biceps. Exercise Instructions Step 1 Start in a hanging position. Step 2 Without swing or using too much momentum, pull your knees up to your chest. Step 3 Lower your legs back to the starting position.