I cannot do ab crunches properly so I asked a trainer for advice and she suggested yoga or pilates. I have practiced yoga a couple of times a month for quite a few years now. It can be done while sitting at your desk at work. Learn about yoga poses and yoga health benefits and see how simple it is to "strike a pose" and strengthen and lengthen muscles. The boy makes fun of me for yoga but he and his dad are both cursed with tight hamstring muscles that cause them to shift most of their walking momentum into their hips, thus causing backaches. I have said yoga is the cure but recently C's physical therapist backed me up completely on that as did his toe surgeon.