How to understand which chair is the best for posture correction?
Most people are aware that the discomfort that they experience when sitting, especially for long hours, is the result of poor sitting posture.
The challenge is to best understand what is the best chair to correct posture and to get there, we need to understand what is the correct sitting posture.
Traditional ergonomic office chairs used to encourage that a person sit with a 90 degree hip flexion, 90 degree bend at their knees and 90 degree ankle position when their feet are flat on the floor.
Over time it became evident that attempting to sit in this position and fight the forces of gravity that want to push us down, was problematic. When we attempt to sit with a posture like this, it doesn’t accommodate the natural curves of our spine and pelvis and gravity has fun pressing these joints into collapsed positions.
Suggestion of the correct posture while sitting on a chair
Recognizing the effects of this compromised sitting posture, designers and well intentioned practitioners of ergonomics, proposed that rather than changing the design of the current traditional chair design, they would recommend using it in a different way.
The relatively new theory from traditional ergonomists is to instruct users of this chair design, to adjust their back support to a slightly reclined position. The outcome, they believe, is to apply more of the gravitational forces along the entire spine to avoid the collapse that was believed to be responsible for forward flexion of the spine which might compress both intervertebral discs and nerve roots leaving these spaces within the spine.
In addition, with the seat remaining fairly level, the users hips were allowed to present a more open hip angle, which would theoretically reduce pressure on the internal organs.
A couple of negative outcomes come with this position.
First, the user now must sit further from their work surface t maintain this recline of the back support. When assuming this position, the user must then reach to their work surface, key board and mouse, which results in the unnecessary engagement of the upper back, shoulder and neck muscles to sustain. With this occurring a whole new set of musculoskeletal disorders are presented.
Second, when attempting to maintain this position, with a reclined back support and a relatively flat seat, there is a tendency to slide on the sit surface, causing a position of sacral sitting where the pelvis is tilted rearward. With the pelvis tilted like this, the lumbar spine in particular flattens and the result is increased forces between the vertebrae. Displacement of the gelatinous disc and pressure on the nerve roots.
The symptomatic reaction was to introduce a slanted foot support to accommodate this reclined position and provide some resistance to the tendency to slide. With any muscular resistance through the legs to sustain this position, relatively isometric forces are now introduced that bring on potential new problems.
An alternative correct sitting posture
An alternative correct sitting posture is to focus on the pelvis such that it maintains an upright vertical position and allows the spine to find natural extension and balance similar to what we experience when standing.
CoreChair designed a human interface to attain this correct sitting posture that focuses on the neutral but embraced pelvis. It accomplished this in several ways.
First, the seat is sculpted to not only evenly distribute forces on the sit surface but also diminish the opportunity for the sit bones to slide on the sit surface to prevent sacral sitting.
Second, CoreChair also introduces a short back support that applies force on the top of the back of the pelvis, maintaining this vertical position of the pelvis.
Together these to design features embrace the pelvis to keep it vertical, addressing this much like a pair of Birkenstock shoes or orthotics, embrace the prominent bony structures of the foot.
The result is a more upright extended spine beginning in the lumbar region and ascending upward to attain the natural shapes of the human spine.
Third, by allowing the sit surface to tilt down to the front and reducing the tendency for the sit bones to slide with this position, the hip angle is allowed to stay more open, reducing pressure on the internal organs but also biomechanically maintaining a more vertical pelvic position.
The overall result is a correct sitting position where the foundation or pelvis is supported and the spine is allowed to move into a more natural extended spine that resists the effects of gravity by allowing this force to press downward through the natural structural shape of the vertebral column.
The users head is allowed to find a natural balanced position with the ears comfortably positioned over the users shoulders.
The user is able to move forward toward their work surface and can allow their arms to naturally hang at their sides reducing, the strain on the upper back, shoulders and neck.
With the spine less supported but balanced, the spine is allowed to assume more natural movement of flexion, extension and rotation which is otherwise inhibited by the reclined and overly supported high back of traditional ergonomic chairs.
CoreChair further enhances their design for correct sitting posture by introducing movement of the entire chair, allowing engagement of core stabilizing muscles, stimulation of nerve roots, enhanced circulation of blood and lymphatic fluids as well as vestibular stimulation.
For persons who have spent their career sitting in traditional chair designs and now searching for the correct sitting posture, this CoreChair design may seem a bit uncomfortable at first. Indeed it is much like beginning a new exercise routine where the previously dormant and likely weaker core stabilizing muscles are now challenged. This discomfort, while not common to all, is a good sign that a healthy dynamic activity is taking place and this correct sitting posture will have a carry over effect to their other activities of daily living much like an effective exercise routine.
When you begin your search for the correct body position, be aware of your body, how it is designed and how it is best maintained.