When you first start using the wheel, you may feel a bit bruised- which is usually an improvement on the discomfort you had been feeling, however, you might like to fold a small hand towel on the wheel and use that as cushioning for a couple of weeks, or just use the wheel a little less time and every second day, until your body gets used to it. Also, make sure your spine is in the spinal groove on the wheel, which makes it feel comfortable to use.