Workstation Seating and Your Spine- A New Paradigm
As a massage therapist I am treating back pain on a regular basis. If you have occasional back pain you can get by with traditional seating, the big fat lazy chair, but if you deal with constant back pain it is probably time to rethink your seat. We are going to begin with a bit of theory. If you don’t want the theory then scroll down to the end of the article.
The human spinal column consists of twenty-four bones, or vertebrae, stacked on top of a sacrum (which in itself is actually five bones fused together). Our spine is ‘S’ shaped, with the bones and curves allowing for movement and shock absorption, with our centre of gravity located midway through these curves.
When we are born, our entire spinal column is curved in one direction (thoracic). In the classic fetal position there is no ‘S’ curve. We develop secondary curves, which create the ‘S’, after leaving the womb. These (lordotic) curves are seen in the five lumbar vertebrae of the lower back (L1 – L5), and in the seven cervical vertebra of the neck (C1 – C7). We develop our cervical curve as young babies when we learn to raise our heads up. Our lumbar curve is created when we first learn to stand up, and then walk. This is all an adaptation to gravity, the force that never sleeps.
Once we develop our ‘S’ curve, our brain comes to see this as normal, and will usually let you know if any given postural position is flattening or exaggerating one of these curves. First you will feel a slight burning sensation, then a feeling of fatigue and tension in that area. If you have any underlying issues (such as degenerative disk, previous herniated disk, loose ligaments etc.) the brain may tell the muscles in that area to protect the region with a muscle spasm. Back spasms are absolutely no fun at all. Symptoms vary from localized pain, to pain radiating down the corresponding limb, to intense pain causing immobility as the muscles shut down under load. If you have ever experienced these symptoms, you will find the seating options below worth checking into.
In 1962, German orthopaedic surgeon Hanns Schoberth demonstrated, by x-ray photos, that in a seated work position, you typically only bend 600 in the hip joints (see right angle sitting position). This means that when moving from a standing position to the classic upright sitting position, you rotate the pelvis approximately 300. This flattens out the lumbar curve and strains the lower back. Once our lumbar curve flattens, our head moves forward, due to the gravitational shift. This in turn, causes the shoulders to rotate forward. This pattern of tension is what I constantly see in my profession, as a massage therapist (neck and shoulder tension, with or without back pain, often due to the classic upright-seated position).
People with healthy backs and necks might be able to get away the conventional seating position with just mild discomfort, but anyone with an underlying issue will soon feel pain. So, what are your options? The most common solution is to add lumbar (lower back) support to your seat. While I highly recommend lumbar support for everyone, your pelvis is still trying to flatten your lower back due to the horizontal position of your thighs. Another option is to recline the back of your seat a bit, allowing the lumbar curve to re-establish itself (lazy boy or sports car driving position). Some office chairs allow for this position. While this helps the lower back problem, it tends to bring the head and shoulders forward, causing neck and shoulder issues. The next option is an upright position that doesn’t ask the pelvis to rotate (keeping thighs at least 300 off of the horizontal). You have probably used this position before if you’ve ever nuzzled up to a bar. Bar stools are higher than chair seats, allowing the thighs to drop downward. Another example of seated posture that encourages healthy back curves is the horseback riding position. Several companies, such as Bambach or Swopper, have designed chairs and stools that allow the thighs to drop the necessary 300, encouraging healthy back curves. Traditional seating is typically 16 – 21 inches off of the ground. To re-establish the lumbar curve, these alternative seats are set 20 – 28 inches off of the floor (roughly one third of your body height). Keep in mind that as you raise your body, your work surface will also need to be elevated. The ideal solution is the sit stand desk or workstation. The recommended work surface elevation in this set-up is your height divided by two.
If your job requires any amount of sitting, and you have ongoing neck or back issues, I highly recommend that you check into alternative seating. This means moving away from the 90-90-90 paradigm that sees all body limbs being bent at right angles to each other. If you try using this new seating position, break your body in slowly, giving it time to adapt. Begin by spending one hour per day on these seats and then increase that time each day. As with any ergonomic change, it is possible that as you fix one problem, a new one can develop. However, if you live with spinal discomfort or pain, this seating style is definitely worth a try. Most saddle chairs and stools are available with or without backrests. For more information on this topic, or for product information, check out the following sites.