What should we pay attention to when choosing a revolving chair
Life of modern man has been dominated by the sitting position. Research shows that we sit about 13 hours every day, while during our entire working life – 80,000 hours. The numbers become important when we sit incorrectly. And it is known that as many as 67 per cent of all employees sit in an incorrect manner i.e. without any contact with the backrest, with legs folded and without any foot support. The most common health problems among office workers are: headaches and problems with concentration (14 per cent), pain in the neck and shoulders (24 per cent), backache and spine ache (57 per cent), problems with pelvis (16 per cent), pain in thighs (19 per cent), pain in knees and calves (29 per cent).
You can combat these problems by using a chair that is designed according to ergonomic principles and by sitting correctly applying the ergonomic principles.
An ergonomic seat should take into account anthropometric features related to a human’s size, physiological and mental capabilities, aesthetic needs and safety requirements.
The recommendations refer to the possibility of adjusting the height, depth, width and tilt angle of the seat and backrest, of setting the height and span of armrests, of shaping the backrest and seat according to physiological curvatures, of matching the adjustment range with body proportions and sizes, of synchronizing the locations of chair elements, of adjusting the cranks and levers to the palm shape and of providing easy access to them. The operation should be comfortable, construction should be stable, there should be a lock to the rolling mechanism and sharp and protruding edges should be finished off. It should be easy to keep them clean, the filling material should be elastic, the colors should in harmony with the shape and with fashion.
When choosing a chair for work, first check if:
- it is stable – stands on a base with at least 5 legs,
- it enables free movement of shoulders,
- the seat surface is flat and its front half bends backwards at the angle of 3 – 5 degrees (front edges should be rounded),
- the depth and width of the seat is 40 cm,
- the height of the backrest is 55 – 60 cm and its surface is convex at the level of the lower abdomen and concave at chest level, which helps the back muscles relax,
- it is upholstered – upholstery dimensions should allow the body to sink 2 – 3 cm,
- the height adjustment range is from 40 to 50 cm,
- we can tilt the backrest backwards by 30 degrees and forward by 5,
- it has armrests with adjustable height and distance between them,
- it revolves 360 degrees,
- mechanism is: CPT (Permanent Contact) or Synchro.
The chair we plan to buy should have a mechanism enabling dynamic sitting, which means that both the seat and the backrest should actively follow changes in our position (Synchro mechanism).
At present we can buy an adjustable chair or a chair equipped with mechanisms that adjust to our figure. We should remember that CPT mechanism or Permanent Contact, or a popular screw at the backrest, is used for static, not dynamic adjustment of the seat!
The most important thing, however, is that with the dynamic sitting mechanism the front part of the seat should not raise when the backrest tilts because it puts pressure on the lower leg and blocks blood flow, which results in leg numbness. |
