Sitting Smarter

13 August 2008

By applying simple technology from Dauphin, it is now possible to see how an employees can adjust their chairs and sitting posture to reduce the risk of muscle tension, headaches and drowsiness. Jane Fenwick reports

Sitting down is not a natural position for homo sapiens. However, most people are increasingly adopting a daily routine that involves sitting. We sit for meals, sit to travel in cars or public transport, sit to operate PCs and laptops at work – and increasingly at home – and sit to watch TV and films. The General Medical Council has estimated that workers spend so much time in a sitting position it often leads to tension, headaches, backaches and a decline in productivity.

The ergonomics of sitting is not a new science and it has been led by the many of the manufacturers of workplace seating who have designed excellent products to adjust and fit the needs of an individual’s body. The ergonomic solution for sedentary employment is to encourage movement as people work. A dynamic seated posture should encourage spinal column movement to ensure that the 100 joints in the spine are in constant movement, and the back muscles are stimulated and blood circulation optimised to facilitate the
supply of oxygen around the body. The office chair should follow the user’s every movement and encourage them to change their posture.

The trouble is while you might feel the symptoms of a poor seating posture you can’t visualise what you are doing wrong to rectify it – until now. Seating manufacturer Dauphin has been researching the problem for some time in its Seating Research Department. Their latest invention is the Ergo Mouse which can actually measure posture easily and accurately.

Looking much like a computer mouse, the Ergo Mouse is rolled up and down a individual’s back to compare the curvature of the spinal column when standing to its shape when seated. It can demonstrate to the employee how the pelvis rotates backwards when in a sitting position by up to 50º and deforms the spinal column, and how this can be brought back into balance by adjusting the chair mechanism.

Up to four Ergo Mouse measurements can be taken.

1. The spinal curvature in an upright standing position

2. The spinal curvature in the normal working sitting position,

3. The working sitting posture after adjusting the chair ergonomically

4. The adjusted seat tilt angle corresponding with the measuring point.

A simple graphic provides a visual representation of the standing posture compared to the seating posture and clearly demonstrates the deformation of the spine in the seated position. Comparing measurements 1 and 2 shows the difference in spinal form and to identify problem areas in the back. Measurements 1 and 3 are compared to see how the seat tilt can be adjusted to ensure that the spinal form is nearly the same as in the upright position. These measurements and graphics can be printed off help staff to visualise why they should use an ergonomic adjustment, and included in an ErgoPass, a ‘passport’ that provides a written reminder of the adjustments needed.

The Ergo Mouse is designed to be userfriendly so than almost anyone can take the measurements after a short introduction. It enables people to better visualise the interrelationships in their sitting habits, making
it possible to understand the processes and the consequences. Dauphin has found that in its experience when people clearly understand these relationships it really does encourage them to change their behaviour. They become experts in their own posture and learn preventative measures to integrate into everyday life. Dauphin’s use technology advances do not stop there. Their Mini-EMG uses electromyography
to measure and document the muscular tension in the neck, shoulder and nape areas resulting from incorrect posture. Any muscular tension resulting from an incorrect posture can be documented using
electromygraphy with the objective of training people to regulate their own posture with the help of their chair to restore their muscular balance.

The Mini-EMG is connected to the user’s PC and shows a warning symbol when a longer term of static holding of the muscles occurs which would often result in muscle cramping in the neck. The electrical activity of the muscle group is recorded when the muscles are both inactive and in motion. The onscreen display shows the individual where excessive strain is being placed on the muscles and suggests possible ways of changing sitting habits.

Employees can practice and learn how to sit with the chair in a dynamic seated posture. This involves exertion and relaxation as well as putting a strain on the muscles and then relieving this strain on an
alternating basis.

The final part of the process is Dauphin’s iSeat. This is an optional teaching chair designed for monitoring
sitting habits over the longerm term. Where an individual is sitting incorrectly and suffering the consequences of muscle tension and pain, a special sensor system in the chair linked to software provides a visual and audible warning on their PC monitor when they are sitting incorrectly. Once the alarm sounds the individual can adjust their posture.

A typical situation might be when an individual spends a relatively long period on time sitting on the front edge of the seal or without making contact with the backrest, a message is shown on their PC to remind them of the need to correct their posture.

The current best advice about sitting for work is to keep moving, to take regular breaks and to ensure your workspace is planned and designed with optimum ergonomics in mind. The development of more flexible working is not likely to add to the ergonomic problems of sitting. As more people move to a more flexible working environment this implies that they will be moving around more than in a static office environment.

Problems with posture arises from the time sitting passively in one position. Dauphin says there is no particular group of workers – male or female, stressed or calm, fat or thin or fit or unfit – who have a better or worse posture. People get passive behavioural patterns instilled at an early age and they can recall them unconsciously. Sometimes people believe it they have a synchronised chair then their posture is automatically ergonomically correct, but as the Ergo Mouse can now show, getting the adjustment right, moving while sitting and keeping the spine in shape are keys to a good posture.