Workstation ErgonomicsPreventing RSI and Musculoskeletal Injury for Office Employees

Housekeeping

Overview

• Practical case studies• Anatomy of the spine• Overview of office ergonomics• Ergonomics best practice

What Is Ergonomics?

• Ergonomics is concerned with the ‘fit’ between people and their work environment.

• It takes into account whether an individuals workstation is set up to ensure optimal comfort and productivity in the tasks they have to perform on a daily basis.

Case Study: Alex• Complaint:– Sore neck and shoulder on the right side.

• Assessment:– His right shoulder was sitting 1-2cm higher than the

left. – Alex leans forward in his chair whilst working. – Works with his keyboard tilted upright.– Using 2 screens with both of them being positioned

to the right of his view.– Alex works 8hr days at the computer.

• Changes made:– Raised the height of Alex’s chair in order to promote

a drop in the right shoulder.– Myofascial release of the right shoulder in order to

promote shoulder symmetry.– Flattened keyboard to reduce the risk of carpal

tunnel.– Centred both computer monitors reducing the

amount of time with his head turned to the right.– Encouragement to take micro-breaks (1 every hour).

Case Study: Kelly• Complaint:

– Pins and needles/numbness in the right arm when using her mouse.– Frequent headaches.

• Assessment:– Possible nerve compression whilst typing.– Elbow “grinding” on the corner of her desk.– Right shoulder sitting higher than the left.– Lumbar curve of the desk chair not supplying enough support to Kelly’s

lower back.

• Changes made:– Moved entire workstation to have Kelly sitting in a

position that her elbow would not grind on her desk.– Chair height adjusted to reduce the elevation of her

shoulder to use the mouse.– Using a footrest to ensure her feet were sitting at the

right height after adjusting her chair height.– Kelly was to trial a new chair with increased lumbar

support for 2 days and report back on how it felt. If it made her develop back pain she was to move back to her old chair.

• Changes made:– Keyboard placed flat to reduce pressure placed

through her wrists and reduce her risk of carpel tunnel.

– Adjust computer monitors to reduce neck rotation. One was vertical and the other horizontal due to reduced desk space.

– For headaches it was suggested she take vision breaks once every 30 minutes which involved looking at something further away from her screen (e.g. Out of one of the windows) to make sure she was using both her short and long sighted vision.

Has 3 main functions

1. To protect the spinal cord

2. To allow movement

3. To support the upper body

The spine is made up of 33 bones called ‘vertebrae’

which form an ‘S’ shape

The Spine

The Spine

• In between your vertebrae are discs providing stability, flexibility and shock absorption to the spine

• The discs have a fibrous outer layer and a gel-like centre

• Correct ‘S’ shaped spine reduces muscle activity, disc pressure and reduces vibration to the brain through its shock absorbing shape. Vibration to the brain can cause headaches.

Scoliosis

The Spine

Scoliosis

Hip hike

• When a portion of the gel-like centre of a disc ruptures and bulges outside of its original boundary

• The bulging disk can pinch surrounding spinal nerves resulting in pain and restrictive movement

• Poor working postures and poor manual handling techniques accelerate disc ageing which can lead to a herniated disc

What is a Herniated Disc?

Muscles

• Muscles attach to all different parts of our body to give us the movements that we carry out every day.

• Muscles that act together are called ‘synergists’, by working together your muscles greatly reduce the amount of work they need to do.

• For every action a muscle performs there is another muscle that will perform an opposing action, these muscles are known as agonists (acting) and antagonists (opposing). Sometimes an imbalance can occur in these muscles.

What is cumulative wear and tear?o Normally, body structures

gradually deteriorate naturally from use.

o Can be accelerated by repeat low-level insults to a body region, such as with repetitive use

o E.g. Chronic back pain, carpal tunnel syndrome, shoulder/rotator cuff tendinitis (inflammation), lateral epicondylitis (tennis elbow).

Proactive vs Reactive Ergonomics

• Proactive Ergonomics– Looks at the persons environment and makes

recommendations and necessary changes to prevent injury.

• Reactive Ergonomics– Considers making changes after injury or

workers reporting discomfort.

Proactive Ergonomics

• Most preferred by employers.• Greatly reduces lost time injuries.• Increases productivity of their employees.

• It involves:– Group training about key ergonomic principles.– Individual assessment.– Design before a worksite is ‘fitted’

Assessment• Consider:

– What is the job being done?– What are the physical and cognitive demands on the worker?– What is the equipment used?– What is the information used?

Best sitting position

o90 degree rule

oNeutral

oEye contact with top third of the screen

Best Practice

• Chair:– An office chair should always have these 3 basic

features:1. An adjustable backrest.2. A 5-point base with castors.3. A well-padded seat.

Best Practice• Chair:• Common complaints:– “I experience back pain when sitting”– “I experience leg discomfort when sitting”– “My chair has arms and doesn’t fit under my desk”

Best Practice• Monitor:• Common complaints:– “I experience neck pain when looking at the

monitor”

Best Practice

• Desk:– Ideally your desk should:• Have a working surface that is all the same height

and have enough space to perform a variety of tasks.• Be high enough to provide room for your legs

underneath.• Be at least 55cm deep to allow for leg room.• Be set up so that frequently used items such as a

pen, coffee cup, mouse or phone can be reached without having to lean forward.

Best Practice• Telephones:• Common complaints:– “I have to lean forward to reach for my telephone”– “I frequently talk on the phone whilst writing or

typing at the same time”

Mouse

• The mouse should be placed within easy reach to the side of the keyboard. Ensure the wrist is at a natural and comfortable position when they’re using the mouse.

• Common complaints:– “I have to lean forward to reach for my mouse”– “I experience pain in my wrist when using my

mouse”– “I experience pain in my fingers when using my

mouse”

Keyboard• Common complaints:– “I experience pain in my neck and shoulders when

keying”– “I experience pain in my wrists/ forearms when

keying”– “My work is primarily computer-based with very

limited opportunity to alternate tasks”– “My keyboard is too narrow”

Vision• Common complaints:– “My eyes become strained/ tired when using the

computer”

Laptops• Laptops are designed to only be used over short periods

of time. They should never be used as a primary computer.

• Common complaints:– “I use a laptop as my primary computer”– “I transport my laptop regularly and it makes my

shoulders sore”

Body Part Affected Common Contributing Factors What can you do?Back of neck Looking down at documents or at the

keyboard Use a document holder. Improve typing skill. Check the height of the monitor.

Side of neck Looking to one side. Cradling phone between ear and

shoulder.

Locate documents and monitor directly in front of them and not to one side.

Use a headset instead of cradling the phone between their ear and shoulder.

Top, outside or front of shoulders

Keyboard too high. Arm unsupported

Raise the height of their chair. 

Lower back Inadequate lumbar support in chair. Adjust the chair height so that the curve of the chair moulds with the curve of their lumbar region.

Remove armrests from the chair.Upper back Twisted or hunched posture. Sit straight on the computer.

Locate documents, screen and keyboard directly in front of them.

Arm or shoulder Arm outstretched or unsupported. Reaching for telephone or cradling

telephone on shoulder.

Move mouse and phone closer to them. Use a headset instead of cradling the

phone between shoulder and ear.

Leg discomfort, swollen feet.

Underside of thighs compressed against chair seat.

Use footrests. Reduce chair height. Look at different chair with different

seat size.Headaches Poor posture, glare, stress, high

workload. Rearrange work are and position of

monitor. Vary tasks and take regular breaks. Reduce the amount of time spent on

the computer. Have their vision checked.

Eye fatigue Screen too close. Glare.

Rearrange work area. Do eye exercises.

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