Starting Position: Lie on your back on a mat with your knees bent, feet flat on the floor and heels a comfortable distance (12-18") away from your seat.
Place your hands behind your head. Pull your shoulder blades together and your elbows back without arching your low back or causing your ribs to splay out. This elbow position should be maintained throughout the exercise. Your head should be aligned with your spine.
Upward Phase: Exhale. Engage your abdominal and core muscles. Nod your chin slightly as you slowly curl your head and shoulders off the mat. Pull your rib cage together and toward your pelvis. Keep the neck relaxed. Your feet, tailbone and lower back should remain in contact with the mat at all times. Continue curling up until your upper back is lifted off the mat. Hold this position briefly.
Downward Phase: Gently inhale and lower your torso back toward the mat slowly and with control. Keep your feet, tailbone and low back in contact with the mat.
Proper form is important for this exercise to prevent excessive stress on your low back. Individuals typically perform this movement too rapidly and recruit the hip flexors to assist with the upward phase. Doing this should be avoided as it causes the pelvis to tilt anteriorly, increasing the stress on the low back. The abdominals connect the rib cage to the pelvis so the movement should focus on bringing these two body parts closer together while keeping the neck and shoulders relaxed.