(Health Secrets) For years our mothers have been telling us to sit up straight, but sitting upright could be a major contributor to back pain, according to researchers from Scotland and Canada.
While hunching forward over a desk is also not recommended, researchers told the Radiological Society of North America that sitting upright at a 90 degree angle can place excess pressure on the spine, causing spinal disks to move out of place. They suggested that the optimum position was 135 degrees, in a relaxed position leaning slightly backwards.
Many office workers spend over ten hours per day sitting down. As well as spending many hours at a desk, people often drive long distances to and from work, and sit down to relax or watch TV when they get home in the evening. Experts believe that the human body isn’t designed for this type of lifestyle and that sitting in the wrong position can lead to long term complications and back pain.
What does the study show?
The research, which was carried out at the Woodend Hospital in Aberdeen, involved 22 volunteers with healthy backs. New magnetic resonance imaging (MRI) technology was used to scan each of their backs. Previously, MRI scans would have involved lying down, but advances in this technology meant that the volunteers were able to move around and assume different positions.
The volunteers adopted three different sitting positions while their backs were scanned. First they sat hunched forward with their feet on the floor as if leaning over a desk, and then they sat upright with their backs at a 90 degree angle to their upper legs. Finally, they sat in a relaxed position with their feet on the floor and a 135 degree angle between their backs and upper legs.
In each position the researchers measured spinal angles and spinal disk heights. They checked for spinal disk movement which occurs when excess weight is placed on the spine and disks are forced out of position. Strain on the spine and the surrounding ligaments, which is characterized by disk movement, can eventually lead to pain, deformity and chronic illness.
The MRI scans showed that:
- When hunched forward, there was a reduction in spinal disk height, which would lead to a high rate of wear and tear on the lowest two spinal levels.
- When upright at a 90 degree angle, the strain on the spine was most pronounced.
- When relaxed at a 135 degree angle, the strain on the spine was least pronounced.
This indicates that leaning slightly backwards at an angle of 135 degrees is the best position for optimum spinal health. This position improves the shape of the spine, making it more like the S shape we adopt naturally when standing. It has also been suggested that sitting at 120 degrees can offer similar benefits, but is an easier position to maintain throughout the day.
Seven top tips for relieving back strain at work
For the many people who sit in front of a computer all day, the following tips should help to relieve back strain in the office:
- Keep your feet flat on the floor and try not to cross your legs or ankles. If necessary get a footrest.
- Find a chair with good lower back support. This will automatically push your back into a healthier position.
- Lower your chair so that your knees and hips are on the same level when your feet are flat on the floor.
- Keep your head and neck neutral so you aren’t constantly looking up or down. The center of your screen should be at eye level.
- Your forearms should be as horizontal as possible and supported on the desk or by a wrist rest. Your upper arms should be as vertical as possible.
- Try to use a desktop PC rather than a laptop, as it’s impossible to get a completely comfortable position when your keyboard and screen are joined together. If you use a laptop get a separate screen or docking station.
- Take breaks every hour and walk around the room. Divide your work into hour long sections and take a break between each section.