The surface of the QOR360 seat is slightly curved to allow front to back rocking without compressing the muscles of the upper leg (biceps femoris) or of the buttocks (gluteus).
The human pelvis is an engineering marvel. Not only does the pelvis allow the spine to balance directly on the the femurs (leg bones) while standing, but the pelvis also provides a sort of “kickstand” on which we can balance while sitting. Called the “sitz bones” (or ischial tuberosities), these two bony prominences are located at the very bottom of the bony pelvis, one precisely beneath each of the femoral sockets. This arrangement allows the legs to rest while the entire weight of the upper body is transferred directly to the sitz bones. Importantly, when we sit on the sitz bones the upper body can use the same reflexes to stay balanced and comfortable that it uses while standing. The slightly curved seat of all QOR360 chairs facilitates perching on the sitz bones. Sitting directly on the sitz bones not only provides clear input to the reflexes required for natural posture, but also facilitates rocking by allowing the pelvis to tip forward and backward without compressing the biceps femoris or gluteal muscles, gently flexing and extending the lumbar spine.