Orthopedic pillows are designed according to different sleep positions. Side sleeping is the most common position, followed by back and stomach sleeping. In this position, you're less likely to snore because it keeps the airways open. For that reason, it’s also the best choice for those with sleep apnea. The pillow for side sleeping should help the body maintain its natural position. Chiropractors recommend the use of a knee pillow when side sleeping, because twisting the hips can lead to back, joint, and knees pain.