I had same problem and I solved this problem with buying
LUMBAR SUPPORT PILLOWS . Our generation spends half of the life sitting. We have become careless about our posture and completely ignore the effects it can have on our body in the long run. A healthy posture is one where the spine is properly aligned. A posture, which offers optimum comfort, including improved concentration, even through long hours of work.
Sitting, they say, is a mechanical interaction between six important body parts: pelvis, vertebrae, muscles, discs between the vertebrae, and the skin. Hence, it becomes all the more important to check and improve our sitting posture. The act of sitting down from a standing position begins with a slightly forward lean of the body (to keep the body balanced) and a subsequent bending of the hips and knees. It is found that About 65% of the total change of angle takes place in the hip joint. If a chair provides you with the appropriate lumbar or pelvic support, there is lesser stress on the lower back muscles. Therefore, it becomes important for us to choose the right chair.