According to Bureau of Labor Statistics (BLS), musculoskeletal disorder (MSD) cases accounted for 33 percent of all worker injury claims in 2011.
Musculoskeletal disorders include everything from repetitive use injuries to low back pain. Low back pain is reported by almost 30 percent of the adult population per two national health surveys. It is also the most common reason why patients visit their doctor.
Prevention of pain is better and usually cheaper than a cure.Research shows that ergonomically designed work areas can reduce the number MSDs, which means decreasing time lost from work. An improperly set up work station can easily lead to headaches, spinal pain and musculoskeletal disorders (MSD).
Ergonomics is the scientific study of workers and their environment, which includes everything from physical stressors to the quality of the air. Ergonomics is applied in an effort to increase productivity, efficiency and quality of work while reducing injury.
By properly fitting your workstation to your body size and shape you may also reduce pain in your wrists, shoulders, neck and back.
First, you need the appropriate chair. The proper chair is different for everyone. The chair should accommodate several factors: Desk height, leg (femur) lenght, and lower leg (Tibia) length.
The proper fit puts the feet flat on the floor and the knees at a 90 degree angle, while supporting the majority of the thigh. The chair (bottom cushion) should not stop in the middle of the thigh.
It has been my experience that when the chair fits the leg in a way that allows not only your buttocks to touch the back but also maintains contact with you leg to just behind the knee, maixmum support is achieved. This allows for maximum relaxation and minimal muscular strain.
Try this exercise. Sit in a chair and adjust the height so that it is in the lowest possible postion theerby creating a change in the knee angle from 90 degress. Notice how this affects the pelvis and low back. It actually decreases the normal low back arch and may even round it completely. Sitting in a chair that causes a flattening or a rounding of the low back (slouching) will create a severe spinal misalignment, and ultimately cause degenerative changes in the spine.
Now try the opposite position. Put the chair at its highest setting and notice the pelvic angle has been increased, which increases the low back arch. This actually pulls on the low back creating muscle strain.
Now try to find the neutral position by creating a 90 degree angle at the knee by adjusting the chair again. Notice that when the knees are at a 90 degree angle there is no strain on the low back. Usually a comparison needs to be made to detect it, but the strain is there. Avoid it by following these guidelines. You'll be glad you did.
There are adjustable platforms that can be placed under your feet that may help achieve the proper knee position. Next is lumbar support. Almost all office chairs have lumbar support built in, but there is often confusion about ergonomically shaped chairs. A chair may be marketed as ergonomic, but because people come in all shapes and sizes, there is no one size fits all.
Lumbar (low back) support should actually come high enough that it erects the torso while sitting. In my opinion, the lumbar support should start at the sacral base and should go as high as the lower mid back. Many chairs offer lumbar support that does not go high enough to support the trunk properly.
Finally, the shoulder blades. The chair, in relation to the keyboard , should be at a height that keeps the elbows at a 90 degree angle. This helps keep the shoulder blades in a neutral position and the muscles as relaxed as possible once the arm is extended outward or raised upward the muscles that stabilize the shoulder blade have to suport the wieght of the arm, which can cause upper back, shoulder and neck pain.
Chairs with retractable armrests should be considered when the armrests and the desk are the same height. A keyboard drawer placed under the desk is also a good option to maximize desk space, as long as you observe the 90 degree rule.
Recently I saw a foam cushion being sold on TV. This is an excellent alternative to hard or concave chairs when getting a new chair isn't an option. Some chairs offer less cushion while others were not designed to be cushioned at all. Cushions easliy make bleachers, wodden chairs and car seats more comfortable and spine friendly.
As for your car, most new cars have the option of additional low back support and for most people it is adequate. For others, there is an easy fix to back pain that comes on or is aggravated by driving. There are soft foam rolls that can be used as an added lumbar support and may be easily purchased online. A rolled up towel is a good substitute for the foam roll if necessary.
The angle of the bottom part of the seat is to be conisidered in the discussion of lumbar support because when the angle of the pelvis is changed the lumbar spine is directly affected. Some cars have the bottom seat tilt option. If your seat does not raise the knees electronically, you can also use the towel for this purpose as well. Raising the seat at the knees will flatten the low back and lowering the seat at the knees will increase the angle of the lower spinal bones. The angle of the torso will also affect the low back.
Reclining the upper portion of the seat while lowering the knees will increase the angle of the low back. The opposite is also true.
If, for example, your are one of the few who feel better with less lumbar support you should raise the knees and put the torso a bit more upright. If you require more lumbar support than just pumping up the lumbar option, try lowering the seat at the knees and slightly reclining the torso. If that is not enough you may use a rolled up towel.