Zero-gravity seats are designed to remove physical stress from the body by keeping it in a zero-gravity or weightless position. These seats are also intended to improve circulation.
Zero-gravity is a concept implemented by NASA that creates a neutral posture, which is the position assumed by the body in a weightless environment. This prevents drivers from becoming fatigued and sore over long distances. In contrast to traditional car seats, these seats eliminate stress from the muscles of the back, pelvis and torso.
Inspired by NASA's advanced human posture research, Nissan debuted its version of zero-gravity seats in the 2013 Altima. According to the car manufacturer, these seats completely support the body and help drivers to maintain good posture at all times. The seats are intended to keep the spine in its natural, resting position. The driver's seat is a six-way adjustable zero-gravity seat, and the passenger side features a four-way adjustable version of this ergonomic design.
Zero-gravity seats are not only available in vehicles. Recliners have also been designed using this technology, with the added ability to elevate the body into a zero-gravity position wherein the feet are level to the heart. Manufacturers claim this posture reduces stress on the heart and improves blood flow.