Abdominal Leg Raises
How to: Lay flat on the floor. Draw navel inward engaging your abdominal wall and to keep the spine neutral. Raise both legs vertical and slowly lower them to the floor keeping abdomen tight. Just before you touch the floor, raise back to vertical.
Compensations: Watch for arching of your lower back, especially when you begin to fatigue. Watch for rounding and elevating of the shoulders.