You Asked for It
October 2002

Sharon:
When you talk more next month about chairs, could you comment on the backless chair where you sit and also rest your lower legs on a padded platform. We've had one for about 10 years and find it quite comfortable unless you already have hip/leg problems.

Enjoy your newsletter each month.
Helen

Kneeling chairs tend to be a controversial item. People either love them or hate them. The concept behind kneeling chairs is that by angling the thigh down, it opens the angle between the thigh and the pelvis. This serves to enhance blood circulation to and from the lower extremities and can increase the amount of lumbar lordosis.

The problem comes back to the issue that humans were not designed to sit. We were designed to hunt and gather, pick berries and throw spears. The activity of sitting flattens the lumbar curve and places continuous load on the spinal muscles to keep the body upright. For this reason, we need to use a chair with a backrest. This allows the postural muscles to relax, increasing circulation to the fibres. A tight, continuously used muscle restricts its own blood supply. This results in a build up of lactic acid and the other by-products of metabolism which causes the burning feeling in muscles. Over time, a build up of lactic acid can damage muscles.

The other issue is that these chairs attempt to keep you from sliding off the seat pan by adding a kneeling surface. Unfortunately, we were also not designed to kneel. The knees were intended for vertical load bearing. The shear forces associated with kneeling strain the meniscus and anterior cruciate ligament. This can create or aggravate knee conditions.

The final nail in the coffin is the difficulty getting into and out of kneeling chairs. After demonstrating gymnastic ability to get into the chair, your legs are trapped. You have to push yourself around with your arms to move from one area of the desk to another. Then, if you lose your balance, you can't get a leg out in time to keep yourself from falling over. I have heard of wrist and arm injuries from people toppling over in these chairs.

Used occasionally, kneeling chairs can offer a source of variety. But, for concentration and comfort, I always recommend a chair with good back support.

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