I was talking with my friend the other day, about her “Ergonomic Chair”. She knew it was ergonomic, because the label said so. None-the-less, it was uncomfortable after sitting an hour or two. I looked at it, checked the adjustments, and found out that in spite of the label, the chair was NOT Ergonomic for her.
Advertisers often use the term ERGONOMIC to describe their products. What they mean can differ. Ergonomics is not a protected term. Anyone can use it to mean anything. For advertisers, it generally means that there has been some consideration of general anatomy or human perceptual capabilities – but this is not necessary.
In general, Ergonomic Design aims to develop products that will be useable by 90% of the population – everyone except for the smallest 5% and the largest 5%. Some products do this by avoiding components where size is an issue (one size fits almost all), others by making several size ranges (thus, our clothes may come in Small, Medium, Large, etc.).
For some items fit is a major issue, for others it is not. Specifications for a T Shirt can be fairly loose. For a tailored suit, they must be much more detailed.
In considering Ergonomic Products (or products designed to improve ease of use or to accommodate to specific needs), the requirements need to be spelled out. Generally, the more frequently used, or the longer the period of use, or the more the accuracy required while using, the greater attention must be placed on the requirements.
Issues with Chairs
In the case of chairs, they are often used for long periods of time. This is what makes fit an issue. The body can generally tolerate a bad fitting chair for short periods without any real issue developing.
Exceptions have to do with previous injuries producing need for extra support (e.g. back injuries), specific settings (such as hip injuries which may require a forward tilt seat) or work activities where job tasks and chair design may not coincide - such as a task requiring the ability to hold upper extremities in a close to neutral position while chair arms prevent this.
Primarily, chairs create problems when:
- 1. They are used for extended periods and the back support they provide is insufficient or in the wrong place (e.g. lumbar support hits in thoracic area or neck support hits on the head)
- 2. The arm rests are too high, restricting elbow and arm position. This may contribute to hiking of shoulders while working.
- 3. There is a mismatch between seat height and desk height.
4. There is no footrest provided when needed.
5. The armrests prevent the chair from moving close enough to the work surface. This creates excessive reaching and contributes to poor positioning in use of work tools, and/or poor sitting posture.
6. The Seat pan is too shallow or deep. In the first case, the chair does not provide adequate support to the legs. In the second case, the length of the seatpan means the person cannot sit back in the chair without causing excessive pressure on the back of the knees and placing the back in a stressed position.
These days, good ergonomic work chairs comes in several sizes. Often, you can order the back separately from the seat allow a really good fit. Most reputable chair compaines will provide fit charts to help you choose the chair. Many will provide a skilled fitter who will come to your office to assist in making your choice.
Employers may complain that this will mean that the chair is too personalized, and the next employee may not fit that chair.
For small companies with low turnover, this may be true. They may wish to enter into a chair purchase program with their employees that would allow the employee to buy their chair when they leave at a discounted price.
For large companies, sizes tend to balance out. If there is a chair corral (storage area), new employees can be fitted to a chair that fits from among the unused stock.
As you may be able to tell from the list above, there are three main issues. One is the fit of the chair for the person. Second, how it interferes or supports the work. The third concern is the interplay between the chair and the rest of the work area.
For a chair to be truly ergonomic for a person, it must both fit the person and fit the tasks they are assigned. When this happens, research shows increased productivity and an increase employee morale.