ERGONOMICS + DESIGN

“Ergonomics” is a word that we are hearing more and more often and there is a reason for this. Ergonomics, put simply, is the science of how human physical abilities and limitations interact with the layout and properties of the workplace.

It is about designing the workplace and workplace equipment so that it is optimizing the range of human physical movements, and not placing strain on the worker through repetition of movements that strain the body, causing it damage, fatigue, or contribute to the worker not being able to perform properly.

A cursory look at most offices may not reveal much, but a closer inspection may reveal a range of ergonomically unsound practices that could result in injury, stress and loss of income. All businesses need to be aware of the potential for income loss and staff injury if they do not do an ergonomic assessment.

ERGONOMIC SEATING
Ergonomic seating can be defined as “a comfortable working posture with a natural alignment of all your joints from head to toes”. Before discussing on how to set your computer workstation, let’s discuss the concept of Neutral Body Positioning.

This method of Ergonomic Seating helps you reduce the stress and strain on the muscles, tendons, and skeletal system thus reducing the risks of developing health problems.

If you are a person who would like to maintain Ergonomic seating while working at the computer workstation, then you should be considering the following instructions:

  • Ensure that your hands, wrists, and forearms are in a row, straight, and almost parallel to the floor.
  • Ensure that your head and torso are in-line with head slightly bent forward, facing towards the front, and balanced.
  • Ensure that your shoulders are at ease with upper arms hanging normally at the sides of your body.
  • Ensure that your elbows are close to your body and bent between 90 and 110 degrees.
  • The feet should be either supported by a footrest or should be relaxing on the floor.
  • While leaning back or sitting in a vertical position, ensure that your back is supported fully with firm hold on the lumbosacral area.
  • Your seat should be well padded in order to support your hips and thighs.
  • Ensure that your knees and hips are in almost the same height with your feet slightly forward.

Even though you are positioned in the best of the postures at your workstation, it is not healthy to continue in that posture for long hours to maintain a good Ergonomic Seating. It is ideal to change your position every now and then.

TIPS

The following are some tips to maintain good Ergonomic Seating and thereby reduce your strain from continuing in the same posture in front of your computer.

    • Your chair and backrest have to be adjusted at regular intervals.
    • Your fingers, hands, arms, and torso need to be stretched periodically.
    • You need to stand up, stretch your back muscles, and stroll around for a few minutes now and again.

CHOOSING AN ERGONOMIC CHAIR

10 RULES YOU NEED TO KNOW

MAKE SURE CASTORS FIT THE INTENDED USE OF THE CHAIR.
i.e. Nylon castors for carpet, urethane casters for hard floor surfaces, etc.
THE BASE OF THE CHAIR SHOULD BE THE CORRECT SIZE AND TYPE FOR THE SIZE AND TYPE OF CHAIR.
In general, larger chairs require larger bases for stability. If bases are plastic, they should be made of 30% glass-reinforced nylon with a metal hub insert.
TASK CHAIRS SHOULD HAVE PNEUMATIC SEAT HEIGHT ADJUSTMENT.
This allows the seat height to be easily adjusted, acts as a shock absorber when sitting down and allows the chair to swivel so you don’t have to twist your back when reaching for things. A brand name gas lift from one of the original manufacturers is advisable, as many lower priced versions are unproven at best.
THE SEAT PAN SHOULD…
Tilt forward and backward, should lock into any position to provide the variation in postures required by the human body, and have a tilt tension control if the seat has a free float mode.
FOR A PROPER FITTING SEAT…
  • The seat size must allow the user to sit back against the backrest while leaving approximately a three-finger width of clearance between the back of the knees and front of the seat.
  • The seat should have a waterfall (curves downward) front edge to reduce pressure on the veins beneath the thighs and should subtly curve up at the sides to redistribute the user’s weight away from their seat bones.
  • The seat should not be ‘dished out’ (dip inward in the centre), which puts pressure on the veins beneath the thighs and should not rise up at the back middle portion of the seat pan, as that puts extra pressure on the base of the spine.
  • The seat pan depth should be adjustable.
TO ENSURE THE BEST SUPPORT FOR YOUR BACK…
  • The backrest must have a firm lumbar support built into its structure, not just the foam, as foam alone cannot provide the force necessary to reposition the lumbar spine back into its natural curvature.
  • The backrest must also have lateral curves to support the upper body, so as to reduce the amount of muscle activity required to keep it in the upright posture.
  • The backrest should be covered with foam to avoid having a hard structure come in direct contact with the user’s back and should not have hard edges that can cause discomfort for some users.
  • The backrest should be the correct size for the length of the person’s back.
THE ANGLE BETWEEN THE SEAT PAN AND BACK SUPPORT SHOULD…
Be greater than 90 degrees to help reduce stress on the structure of the spine. The backrest angle should be adjustable to allow the user to vary their posture.
THE LUMBAR SUPPORT SHOULD…
Adjust up and down to fit people of different body types. A large range in lumbar height adjustment is more necessary than most people realize, as it must not only accommodate people of different heights but people of different weights, especially when additional weight is carried on the buttocks.
ADJUSTABLE ARMS (WHEN APPROPRIATE) SHOULD…
  • Allow the user to pull their chair close to their work surface.
  • Support the weight of the user’s arms to reduce stress on the shoulders and neck.
  • Provide guidance and support when getting in and out of the chair.
ADJUSTABLE CHAIRS MUST BE SAFE AND WELL BUILT TO AVOID INJURY.
A low quality adjustable chair can cause more harm than good.

BUYING THE RIGHT CHAIR

Furnishing your study or office may seem trivial in comparison to deciding on a computer processor or desk but a hasty decision can lead to long-term physical problems. When it comes to choosing a chair, comfort and proper support are key.

We recommend trying any chair before buying. Many chairs are labelled ‘ergonomic’, which should indicate that the model has been specifically designed to support correct posture. However, some manufacturers use the term too freely. Separate Australian Standards apply to ergonomic fixed height chairs (AS/NZS 4468) and height-adjustable swivel chairs (AS/NZS 4438).

Ask if the chair conforms to the relevant Standard to be sure of the validity of any claim. Standards also cover strength, durability, stability and safety.

TYPES OF CHAIRS
There are hundreds of office chairs on the market. They come in a wide variety of styles such as:

  • Fixed height
  • Adjustable height
  • Low backrest
  • Tall backrest
  • With arms
  • Without arms
HOW TO ADJUST YOUR CHAIR PROPERLY
  1. Adjust the height so that your shoulders are relaxed in the working position and your feet rest flat on the floor. You may need to lower your desk, if possible, or use a footrest to support your feet and legs.
  2. Adjust the backrest so that it sits in the small of your back.

No matter how comfortable your chair is, you should always take regular breaks and vary your activities to relieve tension in your muscles.