New open box Side sleeping will put pressure on your back, and make your pelvis tilted and twisted causing the pain. The orthopedic knee pillow comfortably supports your legs and knees, to provide proper spine alignment & positioning to help reduce back, hip, leg, knee, and sciatica The central airflow hole design is better for increasing air circulation and pushing the heat outward away from your body, preventing you from feeling overheated. The pillowcase is made of upgraded cooling ice silk, the new cooling technology keeps the sleeping knee pillow cool and dry even after all-night use