If you suffer from back pain, then knee rolling to side is a great exercise to relieve some pain and gently increase the range of motion of this area.
Performing knee rolling to side is easy. Start by lying on your back on a comfortable surface - if you have hard floors, an exercise mat will help with stretches such as this.
Keeping your feet flat, bend your knees up, then keeping your knees together, roll them gently down to one side. Pause, holding the position for 5 to 10 seodns, then bring your knees back up.
Roll them down to the other side, pause and return. You can repeat this 5 to 10 times for each side.
Those who have a good range of mtion will be able to get their leading knee to touch the ground. If you cannot do so, simply go as far as you can, and hold that position.
Over time you will gradually increase the range of motion and get your knees closer to the ground.
As with all back exercises, you should stretch to the point of tightness, but never to the point of pain.