Lie on your back on the floor with your knees bent and your arms placed behind your head as shown.

 

Contract your abdominal muscles, and lift your head, neck, shoulders, and upper back off the floor. Use the strength of your abdominals to perform this movement, not your lower back muscles.

 

Then lower to the starting position (shoulders off the floor), controlling the downward movement with your abdominal muscles.

 

Repeat the exercise for the recommended number of sets and repetitons.