|
Office workers tend to suffer from neck and back pain due to sitting for long hours without breaks. Lea Wee finds out how to pick a good chair and adopt the right posture
 The most ergonomic chair and the best sitting posture will not keep an office worker pain-free from prolonged sitting unless he also takes frequent breaks, said physiotherapists here. Prolonged sitting is not the restful activity that most people assume it to be, said Ms Yeo Xiu Lin, a senior physiotherapist at the rehabilitation centre in National University Hospital (NUH). She said: “Unlike walking, where the muscles in the body contract and relax, when a person sits, the muscles in the neck, shoulder, back and legs are constantly contracted to keep the body upright and still.” The result is that blood circulation in the body slows down and less nutrients reach the tissues so more cellular waste builds up in them. This contributes to fatigue and discomfort, said Ms Yeo. Over time, this causes strain and pain in the muscles and joints.
It is not known how common this problem is here, but overseas studies show that office workers are more likely to have neck and back pain compared to non-office workers. Sitting puts a constant pressure on intervertebral discs, which act as cushions between the vertebrae of the spine, unlike walking which exerts a dynamic pressure on the intervertebral discs. Hence, sitting accelerates the wear and tear of the discs. In some people, the contents of the disc can move out and press on a nerve, causing pain, numbness or a tingling sensation. The condition is called a prolapsed disc.
It is important for those who sit for a long time to break the stress cycle by “unseating” themselves every 30 to 45 minutes to get their blood circulation going again, said Dr Kevin Yip, an orthopaedic surgeon at Gleneagles Medical Centre. This break need not take more than two to three minutes, added Ms Wendy Lim Hsin Wei, the principal physiotherapist from rehabilitation services at Khoo Teck Puat Hospital. She said: “You can do some stretches on the chair or walk to grab a cup of water.”
Recently, a large-scale study in the United States showed that the negative health impact of long hours of sitting extends beyond pain and aches. It also lowers good cholesterol, increases triglycerides – a fat that hardens arteries, raising the risk of a heart attack – and produces an inflammatory agent in the blood called the C-reactive protein that is also bad for the heart. And this is regardless of whether the person exercises regularly or has a healthy diet.
The study found that those who took the most movement breaks had smaller waists and a lower risk of having a heart attack. Frequent breaks aside, it is still wise for a person sitting at his desk to adopt a good sitting posture and to buy a chair which supports such a posture. Unlike sleeping or walking, during sitting, the spine loses its natural S-curve, said Ms Yeo. Sitting rotates the pelvis such that the lower back, or lumbar spine, becomes flattened instead of curving inwards towards the body. This creates extra pressure on the spine and pulls at the muscles and ligaments supporting the spinal column. The result? Lower back pain. To regain the S-curve of the spine, a person needs to tilt his pelvis slightly, said Ms Yeo. Otherwise, a chair with a lumbar support can also support this posture.
GOOD SITTING POSTURE
 The secret to a good sitting posture is to maintain the natural S-curve of the backbone. Imagine a line running from the top of the head to the ceiling and that this line is gently pulling the head upwards.
Next, relax the shoulders and pull it slightly backwards to counter the tendency to hunch. Finally, rotate the pelvis slightly to regain the S-curve in the small of the back. The tendency is to go back to the “comfortable” slouched position after a while. Hence, it is important to constantly remind yourself to return to the ideal posture. But no matter how ideal the posture is, it is important to change your position often to encourage blood circulation. In other words, go ahead and fidget, stretch or shift in your seat.
Back: Sit right back in the chair so that the back can be supported by the backrest, but make sure feet are still flat on the floor. Contrary to popular thinking, the ideal and least stressful sitting posture is not a rigid 90 degrees vertical position, but slightly inclined backwards between 100 degrees and 120 degrees.
Head and neck: Keep the eyes looking forward at the computer screen. Do not lean the head forward as this strains the muscles in the neck and back. Instead, move the chair closer to the desk.
Shoulders and arms: Relax your shoulders. Do not hitch them up. Keep the elbow level to the desk to minimise strain to the shoulders. Let the bottom of the forearm, where the bulk of the muscle is, rest against the edge of the table. The muscle bulk acts as a cushion to lessen the contact stress between the arm and the table. Avoid placing your wrist on the edge of the desk as there is little muscle there to act as a cushion.
Thighs: The thighs should be parallel to the floor. Make sure that the seat is not digging into the back of the thighs or knees and creating contact stress. Feet: Adjust the height of the seat so that the feet can rest flat on the floor. This reduces pressure on the lower back. If the chair is too high, use a foot rest to support the feet.
Sources: Senior physiotherapist Yeo Xiu Lin at National University Hospital, principal physiotherapist Wendy Lim at Khoo Teck Puat Hospital, orthopaedic surgeon Kevin Yip at Gleneagles Medical Centre, CrossCom-Your Posture Engineer
CHAIR-BUYING TIPS
It is best to buy a chair that has many adjustable parts so that each can be adjusted to fit your needs.
Seat The seat’s height should be adjustable so that the feet can rest flat on the floor. It should be deep enough to support the length of the thighs, but not so deep that the feet are hanging off the floor. The seat should not be too soft as a very soft chair encourages you to adopt a C-shaped, rather than an S-shaped curve in the back, thereby creating strain. A breathable padded seat makes sitting more comfortable. Choose seats made of fabric as fabric retains less body heat compared to polyvinyl chloride (PVC), a popular plastic.
Lumbar support Pick a chair with lumbar support. You can also create your own with a rolled-up towel placed at your lower back.
Armrests They should be adjustable for height so that the elbow can rest parallel on the desk.
Swivels A chair which swivels allows the person to move from one spot of his desk to another, so that he does not have to overstretch himself to locate a document, for instance.
|