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Neck and Shoulder Topics |
The back is a complex structure that provides support for your entire body. The main structure of your back is the backbone or spine.
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The backbone is a flexible column of bones called vertebrae which are separated by discs. The entire column is shaped by ligaments and muscles. |
All these structures work together in creating a loadbearing column that allows you to flex, bend and twist your body.
The spine curves naturally to form an "S" shape.
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In addition to providing support, the spine also houses the spinal cord. The nerves that reach to all other parts of your body, branch out from the spinal cord between individual vertebrae.
There are many causes of back problems, poor posture, prior injury, poor health, poor muscle tone, etc. Studies have shown that 60 to 90 percent of all Americans will suffer from lower back pain at some point in their lives. The reason for this fact is simple; sitting is more demanding on our back (particularly the lower back) than standing.
When you sit, your back cannot maintain its natural "S" shape.
This is because, the lower region of your spine is pulled backwards, thus putting increased strain on the muscles that support the lower back. This strain can cause muscular tension and fatigue which, very often, translates into pain.
As your muscles become strained, they have a tendency to relax. You then begin to "slouch" forward which causes the lower back to be pulled backward even more.
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It can also begin to degenerate the vertebrae and put pressure on the discs.
This increased pressure on the discs can lead to back stiffness and pain caused by pinching of the nerves that lead out of the vertebrae from the spinal cord.
Finally, as described in Neck and Shoulder discomfort, static positions can cause muscle tension and fatigue in the back. By sitting still for prolonged periods, you not only cause muscle tension, but put an added strain on the discs of your spine.
Your chair is an important piece of equipment for preventing back discomfort while working with your VDT. A chair should provide lower back (lumbar) support, upper back support and tilting capabilities. It should also be adjustable for proper height and be cushioned to allow you to sit comfortably.
The lower back or lumbar support of a chair allows you to assume the more natural "S" curve shape of your spine while seated. This relieves strain on your lower back muscles, ligaments and discs.
If your chair does not have lower back support, you can use a cushion or small pillow to help provide this support.
The backrest should be contoured to follow the natural shape of your spine and should extend up to your shoulder blades to provide upper back support and take pressure off the lower back. A slight upward curve at the back of the seat pan will also relieve pressure to the lower back.
A chair that allows you to tilt back anywhere from 5 to 20 degrees will help reduce the pressure on your spine even more. A backrest that tilts in relation to the seat pan will cause your muscles to be flexed as you lean back and forth.
Positioning your VDT equipment properly will also help prevent back discomfort. A worktable that is too high or too low will cause you to assume unnatural posture in your chair. You need to make sure that the monitor is positioned and placed at the right height and distance and that all your other working materials are within easy reach on your worktable. Prolonged static positions also contribute to back discomfort. Remember to vary your tasks throughout the day to help you defend against fatigue.