12. Finally a word on mechanisms
The ANZ standard (AS/NZS 4438) was written many years ago ( Sylex Ergonomics sat on the committee that wrote that standard) when most chair mechanisms were activated by two or three handles. A two handle chair activated a gas lift and a backrest tilt, a three handle chair added seat tilt to the repertoire, so some lazy language crept into the office furniture business.
For those that knew no better a 2 handle chair became “semi-ergonomic” and a three handle chair was “fully ergonomic”. This verbal short hand never captured the full story of how to correctly fit a chair to a user and a task. If anyone describes their chair to you as “fully ergonomic”, run.
Further as time has moved on and improvements in components and mechanisms continued, the number of handles became completely irrelevant as it became possible to combine functions and even eliminate functions by having the chair do the adjustments automatically.
An example of this is the Syncron action. Synchron combines both seat and back tilt into one function. If the seat moves the backrest moves in a set ratio, usually 2 or 2.1 to 1. That means it is impossible to make an inappropriate combination of seat and back tilt. It’s like the difference between a manual gearbox in a car and an automatic gearbox, (you can’t make a bad gear change in an auto). It is a vastly superior product to manual/individual adjustments, but the myth persists that more handles are better.
Most people have little or no idea how to adjust their chair so it is no surprise that research from the Ergonomics Dept at Cornell University has found that the more handles knobs and adjustments a chair has the less likely users are to be able to set their chair up correctly. Except for the gas lift, less than half of all people are even aware that their chair has other adjustments.
Most buyers of office chairs are doing it for the first time, so speak to people who actually know chairs, not just someone trying to flog you their product.
At Sylex Ergonomics all of our people are actually trained and certified in ergonomics and we take pride in supplying the right product for the right application and always with an understanding of human needs.