Purpose: The hands over head curl-up with partner pulls is a sagittal plane stability exercise working similar muscles as the short axis strokes. Unlike most traditional core exercises, it forces core stability while using the hamstrings. Directions: Lie on your back with your knees bent and hands over head in a streamline. Next, tighten your core musculature (flatten your back) and have a partner pull on the back of your shins. With your core active and spine stable, raise your chest towards the ceiling, attempting to have the bottom of your shoulder blades lift off the floor. Return slow to the ground. Perform sets of 5 - 10 repetitions with the correct back position.