Posture

We've recently acquired a copy of Functional Anatomy of the Spine by Alison Middleditch and Jean Oliver
which I thought looked useful. In my practice I have been exploring what it means to stand up straight so I was particularly keen to read the chapter on posture. As this was the last chapter it meant skipping the first 326 pages (I will go back and read them at my leisure). I wasn't sure whether I knew enough about the spine to be able to leap straight in at the end like that but it was fine. My knowledge of A&P was up to it and the only thing I had to look up was to find out where the apophyseal joints were.

Most of us have been told at some time to "stand up straight". In response we tend to push our chest forwards, flatten the thoracic spine and pull our shoulder joints back as if we were on a parade ground.  Many of us, particularly desk-wallahs, spend our days slumped over with our spines flexed, over-stretching the muscles and tendons of the back of the body. Then suddenly we might remember our posture and haul ourselves upright. And so we alternate between slumping forward and pulling up. Yuk! It brings tension into our bodies and feels horrible. Why do we do that to our bodies?

I have found that to stand straight without tension with natural spinal curves is extremely difficult and demands a lot of attention But when I find that place it feels wonderful, the chest feels open and the lungs feel as if they are inflating like some sort of buoyancy aid! We have been looking at this in my yoga sessions too. Many of the participants, when shown a picture of the spine viewed from the side, were surprised to see just how sinuous the spine actually is and they too wondered why it is that we try and straighten it out. I don't know the answer but I suspect that it boils down to thought. The mind thinks that the spine should be straight and that it knows best! I was therefore interested to read on page 330 "In quiet standing, assuming that the curvatures of the spine are in correct alignment, surprisingly little muscular activity is required to maintain this position, slight or moderate activity being present for only 5% of the time." and "If the curvatures are not in correct alignment.. far greater muscular activity over the affected area is then required to maintain the upright posture.". In other words if our posture is less than ideal our muscles are having to work harder than they need to. Who, in their right minds, would want to do that?

After 17 years in the IT industry the end of my career was marked with painful RSI problems in my neck, arms and hands. As a result I am interested in learning anything about how to work smarter when sitting at a desk. Having read the chapter on posture a couple of times my understanding of the mechanics of what is involved has increased. Here is some advice based on what I have learnt.

Sitting

When sitting at a table or desk ensure that

• your chair is at least 1/3 of your height
• your table is at least 1/2 of your height
• the table is not too high for the chair. If it is you will abduct your arms (elbows go out to the side) and the muscles of the neck and upper back have to work harder. Try bending your elbows and taking them a weeshy bit out to the side and feel the tension for yourself! I have this problem with our dining table and chairs so I am now sitting on a yoga block to eat.
• Try to have the arms supported when writing or typing as this reduces muscular activity and intradiscal pressure.

Our back muscles have a very limited capacity for static muscle load i.e. they are not designed for holding us in one position for a long time. Change your posture frequently and make sure that your chair allows you to change your position.

If possible adjust the seat of your chair so that it slopes forwards. When we sit the pelvis tilts and the lumbar spine flexes. The greater the flexion at the hip the greater the flexion of the lumbar spine. As the muscles tire of holding us in an optimal sitting position the lumbar spine flexes more. When the body is slumped forwards the ligaments and fibres of the back are over-stretched and there is increased pressure on the discs. Having a seat which slopes forwards reduces lumbar flexion and the body is tilted closer to the working surface.

When we are working at a table we lean forward into the work and don't use the chair back. However when we are sitting to relax it is better to have the chair back reclined a little and to sit with our back supported. This reduces intradiscal pressure. Using a lumbar support in this position allows the muscles to rest and further reduces pressure on the discs.

Lifting

When you are lifting keep the object close to your body. The distance of the object from the body is more important than how you lift it in determining the load on the spine. Squat lift (bend your knees) if possible as this provides the greatest support to your back (but it requires more effort!). If you're lifting with a flexed spine - do it quickly. Whatever technique you are using don't twist or bend sideways while lifting as this can damage joints and discs.

Push Don't Pull When you push the recti muscles are tense and the load on the lumbosacral disc is less than when pulling.

My Knapsack on my back When carrying a load on your back have it lower on your back. This reduces the work of the back muscles.

Finally I was fascinated to learn that a woman is 30% weaker than a man of equivalent height, weight and training and that because her hip joints are more forward than a man's any weight seems 15% heavier.