A posture seat is a chair, or a cushion that is placed on a chair, intended to relieve stress on the spine and back muscles and encourage good posture. One type of posture seat resembles a normal chair with added upper or lower back support, or a head rest. Another kind refers to a seat that has been tilted forward at an obtuse angle to the back of the chair. These special posture seats are designed for people who regularly experience back pain as a result of poor posture from sitting in regular chairs for extended periods of time, such as long workdays behind a computer.
The basis behind an angled posture seat is the theory that the traditional way of sitting with the hips at a 90 degree angle, parallel to the floor, is actually not as anatomically sound as once believed. This theory states that, when seated in this position, the spine is not in the same position as when standing with good posture, and therefore causes muscle strain, making it neither comfortable nor healthy for the back. Instead, it advocates that the sitting surface should tilt forward so the legs are angled forward and down, keeping the spine and back muscles in the correct position.
For those people wishing to try an angled posture seat but who are unable to buy a whole new chair, a wedge shaped posture seat cushion can be purchased and placed on the chair to form an angled platform. Due to the fact that most of these wedge shaped cushions are made of foam for maximum comfort, they often come with a recommended weight limit. Users above the recommended weight limit may flatten the cushion too much to receive any posture benefits.
More traditional, non-tilted posture seats usually add either lumbar spinal support or upper back support to take some of the stress off the spine and muscles. A head rest may also be included to increase neck support for people who spend a large amount of time with the head and neck tilted at an angle. Some seats also add ergonomic cushioning to tilt the seating platform either forward or backward, but usually not to the same degree as a wedge shaped posture seat. Similarly to the tilted options, these posture seats can also be either a specially designed chair or a separate cushion placed on a regular chair.