Ergonomics … literally means designing the job to fit the worker, instead of forcing the worker to fit the job. How does this even need to be a concern? Reports on computer use indicate that headache, midback tension, shoulder tension, forearm, wrist and low back complaints are commonly caused  by monitor height not ideal, extended reach to keyboard/mouse, keyboard and mouse too high, clawing of the scroll wheel using a mouse, awkward posture during typing and unsupported feet or chair not adjusted to fit your back.
When you are working in your office ideally you are supposed to work all day long without feeling discomfort, stressed or pain at the end of the day… because you are out of work not from a ‘torture-company?!.

The fit between yourself and what you do, the objects and environment you work all day determine how comfortable you will be in your office. If good fit is achieved, the stresses discomfort and musculature related pain can be reduced. You become comfortable; do things efficiently and productively without discomfort.

What You Need To Know
There are two basic categories of factors an employer and employee need to consider, the environmental conditions that we are exposed to; our physical surrounding and physical stressors which entail the type of activity we are doing and how that affects our body.

Environmental factors do affect our senses… sight, hearing, smell. Just as with any other aspect of life, excessive exposure to these factors can cause damage to your body       . Some, like Sick Building Syndrome (poor ventilation, off gassing of materials etc) are little complicated because we can’t always identify the problem. Even so, there are things we can do to make our environment healthier.

Physical stressors on the other hand include improper lifting that can cause strain on your back, pulled muscles or slipped disc. Repetitive movements, awkward postures/sustained posture and even contact stress that lead to discomfort which results to musculosketal disorders (ailments of muscles, joints and its structures).
In office work specifically millions of people sustain injuries caused by physical stressors referred as ‘Cumulative Trauma Disorders’ (CTDs) or ‘Repetitive Strain Injuries’ (RSIs). Cumulatively they occur gradually over period of weeks, months and years. Majority of CTDs are caused by repetitive motions that would not result in injury if only performed once such as thousands of keystrokes typing, hours of filling day after day, stamping dozens of papers, frequent lifting and repeated motions with computer mouse.

Contact Stress

Contact stress in the office is basically pressure on the body by a hard edge surface which can reduce circulation and obstruct nerve signals leading to swelling, tingling or discomfort.

Akward Sustained Postures
During office work there are many ways you position yourself in office to use your computer that isn’t the ideal way, it  ends up distorting your S-shaped spine.

Such sustained postures are reasons why 50% of office workers experience back pain once a year and 50% to 85% of those who experience neck pain report symptoms within 1-5 years. So ideally how are you supposed to adjust your office to ensure you avoid back, neck pain and other muscular related disorders? These guidelines will help you to adjust your workstation, just focus on four areas; body to chair contact, feet to floor contact, hands to mouse and keyboard finally eyes to screen.

Body to Chair Contact
To be able to adjust your chair in your office you need to;

  • Move your chair away from your desk first.
  • Adjust the seat height so that your feet feel comfortable on the floor.
  • Raise/lower the back support to fit in the curve of your back. You would either adjust the entire backrest.
  • Adjust the armrests by lowering one armrest completely, bend elbow to 90 degrees.
  • Raise that armrest to hold the forearm in the 90 degree position, without pushing your shoulders up.
  • You can now level the other side with above as reference point.

After Adjusting the Armrest
The armrest you adjusted is it at the same height as your desk/keyboard tray, lower or higher than your desk/keyboard tray.

If your armrest is lower than your desk or keyboard;

  • And you are using a keyboard tray lower the height of the keyboard tray to be level with the armrest you adjusted. This will bring your keyboard and mouse down to your ideal sitting work surface height.
  • If you are not usinga keyboard tray raise the seat up so that the armrest is level with the desktop. Then be sure to support your feet. If your chair will not go high enough, this then means you still need a keyboard tray.

Lets say the armrest you adjusted is higher than your desk/keyboard tray;

  • And you are using a keyboard tray raise the height of the keyboard tray to be level with the armrest you adjusted. This will bring your keyboard and mouse down to your ideal sitting work surface height.
  • If you are not using a keyboard tray lower the seat height so that the armrest is level with the desktop.

Feet to Floor Contact

If your feet are unsupported… Lower your chair seat height then lower your keyboard/mouse or you can use a footrest made locally or the ones in the market but ensure they are not more than two inch height level.

 This may be of need because without ideal support for your feet, your body will adjust itself and this may lead to lower back discomfort.

Hands to Mouse and Keyboard
Keyboard and mouse should be located on the same level and elbows should be 90 degrees. Armrests will allow relaxed shoulders and the keyboard and mouse are close to you.

Also ensure you keep it neutral keep wrists flat.. don’t angle wrists back 

If at all you are using a wrist rest then avoid wrist resting on the wrist rest to avoid putting pressure.

With wrist free without pressure meaty part of the hand rests with no pressure on the nerve in this case you are using your palm support.

Finally Eyes to Screen
Your monitor should be directly in front of you. The centre of the monitor should be in line with your body with your arm length distance from your eyes to the monitor screen.
After following guidelines step by step you will then be able a achieve  a correct sitting posture in your office.

Written by:
Moses Katasi
Physical Therapist

Office Design Ergonomics

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