Do: Sit in a neutral position of the spine with the shoulders over the hips, feet flat on the floor, and chin aligned over the chest. Support the curve of the lower back (the lumbar curve) with a towel or a rolled cushion. When sitting for a long time, take breaks to stand or walk around. Don't: Sit forward with a rounded back and feet unsupported. Any time the back is arched, the spine is at risk. Keep the back flat and straight. The feet should not be propped up. Sit as far back in the chair as possible, so that the back of the body is right up against the back of the chair.Want to read more? Subscribe to one of our monthly plans to continue reading this article.