This is the third in a series of videos about improving your abdominal muscle tone. This can be helpful for some patients with back problems. Make sure you have a look at the first and second videos before you start into sit-ups. Sit-ups are harder work than the first and second set of abdominal exercises. If you have a problem, or it makes your back worse, then stop. This video will give you some tips about how to protect your back when you do the sit-up exercises