A standard leg raise is performed from a hanging position on a pullup bar or a face-up position on the floor. While both of these exercises are beneficial, the captain’s leg raise trumps them both, because as soon as you get into position, your abs have to contract to keep your upper body still. As an added benefit that the pullup bar does not offer, your back is completely supported throughout. To gain the benefits that the leg raise offers, it is important to use proper form.
begin with your back pressed against the back rest, feet on the lower supports and forearms resting on the upper supports with your hands gripping the handles. Slowly remove each foot from the supports and let your legs hang straight down. Keeping your legs straight and together, lift them in the air in front of your body. Once your legs are parallel to the floor, slowly lower them down and repeat.
The motion involved with pulling your thighs closer to your stomach is called hip flexion. Whenever you flex your hips, you work the quadriceps and the hip flexors. The hip flexors run from the lower stomach to the top of the thighs; they consist of the iliacus and psoas major, also known as the iliopsoas.