What is ergonomic design?
Just what does ‘ergonomic’ mean and how does it affect office design, efficiency and health of staff?
When you hear the term ‘ergonomic’ it often brings to mind the way you sit at your desk, making sure the computer screen is at a certain level. But it can also describe the science of designing the office and the job to fit the worker, not forcing the worker to fit the job or the office. Apart from that what else is there?
There is rather a lot more to ergonomics than one would think.
The term is often casually thrown around by health professionals and marketing pundits, and for others it covers everything under the sun. With all this different gobbledygook fluttering around the office it’s no wonder nobody really knows what ergonomics is all about.
The word ‘ergonomic’ comes from two Greek words ‘ergon,’ meaning work, and ‘nomoi’ or ‘nomos’ meaning ‘natural laws’ or ‘law’.
And there’s more. For instance, there exists an International Ergonomics Association and this body of learned souls has coined a term to describe it: ergonomics is the scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data and methods to design in order to optimise human well-being and overall system performance.
Let’s get comfy
Any the wiser? Me neither. That isn’t the clearest definition. So, let’s try again. Ergonomics is the science of making things comfy. Ah, that’s better. It also makes things efficient. And when you think about it, working in comfort is just another way of making things efficient. So, ergonomics makes things comfortable and efficient. At its very simplest ergonomics literally means the science of work. So ergonomists, i.e. the practitioners of ergonomics, study work, how work is done and how to work better.
Ergonomics is also thought of in terms of products, e.g. an ‘ergonomically sound/efficient/designed/correct chair or desk’ is preferred in the modern office so workers don’t end up with repetitive strain injury and have to take time off work to recover, or worse, sue the company for not providing ergonomic office furniture.
In the complex design of services or processes ergonomics can be useful also. It can help define how a product is used, how it meets needs, and most importantly if workers like it.
Comfort is a word often misinterpreted. It doesn’t mean making things soft and cushy but is one of the most important aspects of successful design and concerns the machine-human interface. A primary concern among ergonomists is the mental aspect of a product or service since if you don’t like how it looks or feels you won’t use it and so it’s useless.
The job of any designer is to find ways to make products more useful, which makes it a success in the marketplace. The look, feel, use and durability of a product helps the user decide whether or not to buy or use it, so better ergonomics means comfort and value.
Then we have what happens when the office is not ergonomically sound: humans trying to function in a poorly designed workplace suffer fatigue, frustration and hurt which means they can’t work at their optimum level.
So to remove the risk of workers ending up with musculoskeletal injury, and to boost production, the workplace needs to be ergonomic so workers can do their jobs within their body’s capabilities and limitations and then they can contribute to the company’s bottom line. Simple.
But where do you get started?
A good place is to understand what happens when a worker is asked to do a job that is outside their body’s capabilities and limitations, putting the musculoskeletal system at risk. The role of repetitive movement in injury is not fully understood, but is believed to interfere with the lubrication of tendons, and the ability of muscles to receive enough oxygen.
An ergonomist might suggest that the workstation design doesn’t allow the worker’s recovery system to keep up with the fatigue that will be caused by performing the job. An evaluation will show the ergonomic risk factors and if the worker is at risk of developing a musculoskeletal imbalance and a musculoskeletal disorder or MSD.
There are three primary ergonomic risk factors involved. The first is high task repetition. A job is considered highly repetitive if the cycle time is 30 seconds or less. These tasks often involve hourly or daily production targets, which have to be met. If combined with other risk factors such as high force and/or awkward postures, this can contribute to MSDs.
Awkward postures put excessive force on joints and overload the muscles and tendons around them. Joints operate best when closest to the mid-range motion. Risk of MSD is increased when joints are worked outside of this mid-range repetitively or for sustained periods of time without adequate recovery time.
Ergonomic assessment tools are available and include the NIOSH Lifting Equation (Single Task), NIOSH Lifting Equation (Multi Task), REBA – Rapid Entire Body Assessment; RULA – Rapid Upper Limb Assessment; SNOOK Tables; WISHA Caution Zone Checklist (PDF) and WISHA Hazard Zone Checklist (PDF)
Also, the implementation of work methods that consider and reduce awkward postures should be put in place and workers trained in proper work technique and encouraged to accept their responsibility to avoid awkward postures whenever possible.
Job rotation and job task enlargement is an important way to reduce repeated and sustained awkward postures and counteractive stretch breaks provide the worker with the chance to counteract any repeated or sustained awkward postures and allow for adequate recovery time.
Another thing to remember is that removing ergonomic risk is never finished. The key to sustained lowering of the risk of MSD requires an attitude on the part of workers and managers hungry for continuous improvement.
Also worth noting is that ergonomics is not just about conducting ergonomic assessments — it’s about making ergonomic improvements.
The importance of posture
Good posture is essential for all computer users but there is no single, rigidly defined position. Here are some good rules to consider: Have the computer keyboard in a position that brings the forearms close to the horizontal and the wrists straight, with the hand in line with the forearm. Some workers prefer to have their wrists supported on a wrist rest or the desk. Be careful not to have the wrist extended or bent in an up position.
Adjust the chair’s seat tilt so that it’s comfortable; usually, this will be close to horizontal but some people prefer the seat tilted slightly forwards. The knees need to be bent at a comfortable angle and greater than 90 degrees flexion. Use a foot rest if this puts a strain on the leg muscles, or if the feet don’t reach the floor, keeping the knees at a 90 degree angle. Adjust the backrest so it supports the lower back. A standing desk or workstation can be used intermittently if the worker prefers and the office provides them, but an understanding is needed surrounding the problems that can occur if standing for too long.
Avoiding other risks
When answering calls, avoid cradling the phone between the head and shoulder; use a headset or the phone’s hands-free/speaker-phone capabilities if possible.
Set the computer monitor eye-to-screen distance within an arm’s length, or at a distance that permits ease of focus on the screen and set the height of the monitor so that the top of the screen is below eye level and the bottom of the screen can be read without a marked inclination of the head. Usually this means the eyes should be level with the tool bar.
Those wearing bifocal or multi-focal lenses need to get a balance between where they see out of their lenses and avoid too much neck flexing. Also, document holders need to be close to the monitor screen in a position that causes the least twisting or inclination of the head.
To minimise glare and reflection, place the monitor to the side of the light source/s, not directly underneath. With fluorescent strip lighting, the sides of the desks should be parallel with the lights and try not to put the screen near a window or have the worker facing the window. Other tips to reduce reflection or eye fatigue include turning the screen brightness down to a comfortable level. Look off into the distance to rest the eyes every 10 minutes or so. Change the text and background colours. Black characters on white or yellow background, or yellow on black, white on black, white on blue and green on white. Avoid red and green and yellow on white.
The mouse should not cause undue pressure on the wrist and forearm muscles. If the mouse is large or bulky rather than the preferred slim-line, low-profile type it might keep the wrist bent at an uncomfortable angle. Also, pressure can be reduced by frequent releasing of the mouse and also try to keep the mouse as close to the keyboard as possible, elbow bent and close to the body.
Typing is also important as the ‘hunting and pecking’ fashion adopted by many untrained workers can lead to the tendons on those two fingers taking undue strain. Also, workers using the two finger method are constantly looking from keyboard to screen and back to keyboard, which may strain neck muscles and make the posture tense, with wrists bent back and fingers poised to strike.
It is also recommended that operators take regular postural/stretching breaks to reduce intense periods of repetitive movement. Employees newly engaged in keyboard work, and staff returning from an absence of two or more weeks, need a period of adjustment.
Ergonomic matters can be linked to a wide range of concerns including the working environment, workstation design, tools; vehicles; computer programs and plant. It can also involve cognitive processes such as skilled performance, workload, decision making, and stress. There are ways of dealing with all these things to make sure any difficulties are tackled.