Almost 40 years ago, ergonomic researchers determined that the load placed on the intervertebral discs in the lower back increased over 40% when a person went from a standing position to an upright sitting position. As someone begins to move into a sitting position, they raise their thigh into a position where the backside of the knee is at a 90 degree angle, thereby forcing the pelvis to rotate backwards and turn the tailbone under. This positioning of the pelvis, relative to the spine, starts stacking the intervertabral discs in a manner which places increased pressure on the discs, the nerves which radiate from the spinal cord outward to the lower part of the body, and the connective tissues in the lower back. This increased pressure has a significant potential to lead to cumulative trauma disorder, more commonly referred to as “back pain."
Using patented technology, the designers of these revolutionary chairs were able to design a conventional looking task chair which allows the user to adjust the seat pan with enough downward slope to keep the lordosis curve in the lower back. Combining a seat shell which pivots as the user leans forward, with a convex shaped, specially tensioned mesh surface, the Stealth allows the user to eliminate the harmful loading of the intervertabral discs in both the active working position and the reclining passive or resting position. This new technology also equalizes pressure from the seat surface, thereby eliminating uncomfortable, unhealthy pressure points under the thighs, the tailbone and the hips as the user leans forward to access their work area.
Another beneficial feature of these chairs is its floating, lumbar shaped backrest. While most common backrests are designed with a concave shape, the backrest is shaped to exactly match the convex lumbar curve of the lower back. When this unique shape is combined with a spring loaded, floating backrest mechanism, the backrest “floats” with the user’s movements as they lean forward and backward. The floating motion’s constant rolling up and down the user’s back actually massages the muscles to increase blood flow and increase hydration of the intervertabral discs. This massaging action and disc hydration benefits the user by keeping their back muscles refreshed, even during extended work sessions. Unlike any other chair in the world, these models can be used in a traditional upright seated position or in a forward tilted declining position. So, for the first time in human existence, there is a better, healthier way to sit.