 The human body is not well adapted for long hours spent sitting in a restrictive or constrained posture.In static sitting, the abdominal muscles may instinctively relax and even atrophy over prolonged periods of lessened physical activity.Furthermore, the prolonged postural loading of the spine while sitting, without natural movement and mobilization of the spinal joints, can reduce joint lubrication and increase stiffness, which can be detrimental to back health.