To perform the superman, position yourself in four point kneeling, with hands and knees directly underneath your shoulders and hips. Find your neutral spine by hollowing and arching your lower back and finding a comfortable middle position. Repeat the same process with your shoulder blades and with your neck. Keeping the back controlled in a neutral position, slowly straighten the arms and the hips away from you. Contract the bottom muscles slightly during the leg lift. Do not allow the back to arch or to twist. Only lift your back as far as the stable back allows.
As you become more confident with this exercise you will generally feel that you can lift further while maintaining a neutral position in your spine. The emphasis for this exercise is always on not allowing the back to arch as you extend your arms and legs. Make this your focus, rather than how high your arms and your legs can move.