Ergo Myths

You Can't Fit the Job to Everyone!



Unfortunately, there is a common belief that designing for the full range of the working population is infeasible because it requires expensive engineering design. There are three approaches that can be used to help use design for the full range of the working population:
1.
Design for adjustability
2.
Do not design for the average
3.
Design for extremes

Design for Adjustability
Many engineers question the feasibility of adjustable workstations. The common belief is that workstations need to accommodate 12" of vertical adjustability (e.g. head height difference of a 5' 1" female and 6' 3" male). When you consider that people work with their hands and not with the top of their heads, you realize 12" of adjustability is not necessary. Designing for 4" to 6" of adjustability, the difference in hand working height (elbows bent 90°) of the 95th percentile North American male and the 5th percentile North American female, will accommodate 95 percent of the working population.

Do Not Design for the Average
Who is considered the average person? There isn't one! If you were to offer to buy safety shoes for a classroom of adults, the first question you would ask is, "What is the size of your shoes?" As you record the sizes, you would notice the sample of data would resemble a normal distribution curve. If we purchase only one shoe size (the foot size in the middle of the curve) less than 68% of the people would have comfortable fitting shoes. Those with bigger shoe sizes would not fit into the shoes, and those with smaller shoes would have to stuff them with newspaper. When you design for the average, you limit the majority of the population.

Design for Extremes
The goal of designing for the extremes is to accommodate as much of the population as possible. Size apertures for hand and tool access, tool and part storage locations, clearance and access are all instances in which designing for extremes is the preferred application of ergonomics. Consider the following examples:
•
Hand access – design for the largest male’s hand to accommodate smaller hand sizes
•
Tool and part storage location – design for the smallest female’s horizontal reach to accommodate all reach capabilities
•
Doorway clearance – design for the largest male to accommodate all populations

New safety culture diagnostic tool

from SafetyAtWorkBlog by jonesk99@gmail.com (Kevin Jones)

Scandinavia has been the region of choice for many OHS and industrial relations reforms but now something has come from the other side of the world, New Zealand, which should excite OHS professionals.

The Department of Labour (DoL) has released a “self-help diagnostic tool” to identify safety culture. The DoL Workplace Services Group Manager, Maarten Quivooy, says

“One of the best ways to improve a safety culture is to start measuring it. This tool gives businesses the guidance they need to understand what’s working well and where there is room for improvement…

“It can be used by any industry or business that is motivated to improve its health and safety performance. Ultimately it will help a business make a start diagnosing its culture and, most importantly, planning for change. Building a better safety culture builds a better business.”

The basis of the tool is a short survey which includes 24 simple questions that will generate important discussions individually but could provide a fairly decent indication of a company’s safety culture if the workplace honestly completes it. One early indication of a safety culture is likely to come from the willingness of workers to even participate in the survey.

But this program is not just a “fill and fling” process. DoL provides a very good introduction to coaching which could be a marvellous primer to OHS professionals who have come from an engineering background and are more comfortable with interlocks and cogs than human interaction, but also to those confused paymasters in smaller companies who have had safety “dumped” on them.

Any work on safety culture must be undertaken when a workplace is ready for it. Introducing a safety culture survey while workers continue to be injured or the company has a blasé attitude to OHS may anger the workforce by the survey being perceived as not addressing the more important issues of machine guarding or manual handling. (This has often also been the downfall of many Behaviour-Based Safety attempts)

The DoL User Guide includes a section on getting ready for the survey which clearly states the conditions needed for a receptive workforce:

“Improving safety culture is not an overnight process, nor a silver bullet to all your health and safety problems. It requires sustained commitment and action across a number of parts of your workplace.

How ready your workplace is relates to:

* the state of your health and safety systems
* the condition of your tools, plant and protective equipment
* how open the business is to making changes
* a workplace’s capacity to resource actions (i.e. time, people and money)

If these fundamentals need improvement, you are best to focus on these before tackling safety culture. That doesn’t mean your health and safety approach needs to be perfect before you can focus on your safety culture, but it is worth thinking about where the most pressing areas of improvement are from the outset.”

The NZ DoL should be applauded for helping companies who already know there is “something wrong” with their culture but do not know how to begin. This survey and guide is a terrific start.

Shoulder and Neck Pain

Ergonomic Resources
Ergonomic Tips to Help You Work Better
Tips to Relieve Neck & Shoulder Pain

Shoulder & Neck Aches at Work

Shoulder and neck pain is a common problem for office workers, especially those who sit in front of a computer most of the day. Muscle tension and general aches and pains are not only painful but also a frustrating cause of loss of productivity, whether we miss work or just aren’t as efficient. Try these tips to find pain relief and to prevent future pain.

* Sit (or stand) up straight: The most common cause of pain in the work place is poor posture from slouching, raising our shoulders, or simply contorting our bodies into strange positions without being aware of the strain we are placing on our muscles. In contrast, good posture prevents and relieves pain in your shoulders, neck, and back. Start by adjusting your chair to fit your own body. Your feet should rest firmly on the floor and the armrests should by low enough to allow free arm movement from the elbow. Lower the back rest to fit the curve of your back, and make sure that your lower back is properly supported. Additional lumbar support can be added easily if you need more support. Additionally, many workers are starting to see the advantages of an adjustable height ergonomic desk that they can adjust to meet their needs.
* Take a Break to Stretch: Create a new habit of taking a short break at least once an hour. It doesn’t have to be long, just a minute or two to walk around. It’s important to stretch your shoulders, neck, and back regularly throughout your day.
* Move Your Keyboard: Your arms and shoulders should be completely relaxed while you are typing or using your mouse. If you keyboard is too high, or too low, you tend to tighten those muscles, creating tension and soreness. For pain-free typing, use an adjustable keyboard tray to place your keyboard about two inches above your lap, slightly below your relaxed elbow height. You may also find significant improvement in muscle tension by using an ergonomically designed mini keyboard or a split keyboard.
* Adjust Your Computer Screen: Your monitor should be centered directly in front of you, about 15 to 25 inches away, and sit at eye-level. Looking down or up, turning to the side or leaning forward to look at your screen will strain your neck muscles. Monitor shelves are easy to install and quickly provide additional height.

Neck and shoulder pain can lower your productivity and create additional stress in the work place. These tips can bring relief to your current discomfort, and restore good posture to prevent additional pain. Taking frequent breaks and adjusting your work station can bring quick relief, and maintaining healthy posture can protect you from further damage.

History of the Office Chair-Who knew?

One the earliest known innovators to have created the modern office chair was naturalist Charles Darwin, who put wheels on the chair in his study so he could get to his specimens more quickly.

With the advent of rail transport in the mid-19th century, businesses began to expand beyond the traditional model of a family business with little emphasis on administration. Additional administrative staff was required to keep up with orders, bookkeeping, and correspondence as businesses expanded their service areas. While office work was expanding, an awareness of office environments, technology, and equipment became part of the cultural focus on increasing productivity. This awareness gave rise to chairs designed specifically for these new administrative employees: office chairs. This caught the attention of Otto von Bismarck, who is credited with popularizing the office chair by distributing them throughout parliament during his time in office.

The office chair was strategically designed to increase the productivity of clerical employees by making it possible for them to remain sitting at their desks for long periods of time. A swiveling chair with casters allowed employees to remain sitting and yet reach a number of locations within their work area, eliminating the time and energy expended in standing. The wooden saddle seat was designed to fit and support the body of a sitting employee, and the slatted back and armrests provided additional support to increase the employee’s comfort. Like modern chairs, many of these models were somewhat adjustable to provide the maximum comfort and thus the maximum working time.


In the 1970s, ergonomics became an important design consideration. Today, office chairs often have adjustable seats, armrests, backs, back supports, and heights to prevent repetitive stress injury and back pain associated with sitting for long periods. Ergonomic chairs fit an individual's needs and provide support where the individual needs it. New concepts of office chairs include a seat oscillating forwards and sideways and an oscillating seat back to allow the body to move as much as possible during sitting.