HOW: Start by lying on the floor with your knees bent up and feet flat. Flatten your back by contracting your core and performing a pelvic tilt. From here, lift your legs and arms straight up pointing both the sky. Then reach one arm back and bring the opposite leg down. Once that is complete, perform a side bend to the side that the arm is up overhead. Return to the arms and legs up position and repeat on the other side.
FEEL: You should feel your core and oblique muscles working. You will also feel your hip muscles working bring your legs up and down.
COMPENSATION: Keep your back flat while performing the dead bug and side bends. Keep your legs and arms locked out.