McMaster University

McMaster University

Ergonomics - Workstation Setup

Ergonomics Hazard Factors

Force - When the amount of force required for a job or task is more than the muscles can handle, there is the risk of injury. In the context of a workstation, this may involve keyboard stroking harder than is necessary, gripping writing tools to hard, pressing down or clicking the mouse too hard. Although these are small forces, if constant over time, will cause pain and discomfort.

Posture – The more extreme, awkward or unnatural the posture, the greater the risk of injury to the muscles, ligaments, tendons and nerves. Even after you have set up your workstation, you still require to maintain good posture while seated. This will take time and patience. As with any other physical activity, you have to train your muscles!

Repetition – Jobs that require repetitive motion increase stress to the muscles and tendons because of fatigue wear-and-tear. For computer workstations, notice your repetitive tasks. Can you think of ways to eliminate the repetition? Can you use keyboard shortcuts instead of mouse clicks? Can you create template emails to avoid re-typing the same emails?

Duration – Even though a movement or activity may be fairly comfortable, the duration of the task over a long period can lead to injury.

Additional factors can include contact stress, vibration, temperature, work organization and work methods

Hazard Recognition

  • Recognition, assessment and control of potential ergonomic hazards are keys to MSD prevention
  • Daily workstation review
  • Regular supervisor and workplace inspections
  • Workers awareness of signs and symptoms
  • Documentation Review
  • Injury reports and statistics
  • Work-site adaptations
  • Risk assessment for introduction of new equipment or technology

 

Setting Up Your Workstation

Optimal Workstation Set-Up

  • Feet firmly supported with knees at a 90o angle
  • Hips level with or slightly above knees
  • Keyboard and mouse below elbow level
  • Top line of text at eye level
  • Monitor distance: approximately an arm’s length away

Your Office Chair

  • Provides lumbar support
  • Height can be adjusted
  • Width is appropriate for the individual using the chair
  • Seat Depth- well-fitted or adjustable
  • Adjustable or removable armrests
  • Five prong base
  • Breathable fabric
  • Well-fitted- small, medium or large chair

Adjusting the Height of Your Chair

  • While standing, adjust the height of the chair so the highest point of the seat is just below your kneecap.
  • This should allow your feet to rest firmly on the floor when seated.
  • If you feel pressure near the back of the seat when you sit down, raise your chair until your feet are flat on the floor.
  • If you feel pressure near the front of the seat when you sit down, lower your chair until your feet are flat on the floor.
  • The goal is to evenly distribute your weight.

Adjusting the Lumbar Support

  • When sitting, adjust the height of the backrest so the lumbar pad supports the natural curve of your lower back (lumbar curve).
  • The tilt of the back support should allow you to sit with your upper body slightly reclined.

Adjusting Your Seat Pan

  • When sitting, the seat pan (part of the chair you sit on) should allow you to use the back support without the front of the seat pressing against the back of your knees.
  • If the seat is too deep, try a back support (lumbar pillow) to reduce the size of the seat pan.
  • The adjustment lever is usually located under the front of the chair, much like the lever that moves the seat forward and backward in a car.


Setting Up Your Monitor

  • If using a single monitor ensure it is centred in front of you about arms length away.
  • The top line of text on your monitor should be level with your eye. For those with bifocals the monitor should be positioned lower to limit neck strain.
  • Adjust the font size to make it comfortable to read.
  • Minimize glare by positioning monitor perpendicular to windows and between banks of lights. Use task lighting if required.
  • Adjust the brightness of your screen. Preferred brightness will depend on vision and environment.

Using Two Monitors

  • Consider a keyboard tray that moves the user further away from the monitor if work surface is not deep enough.
  • Use eye movements to view screen rather than head and neck movements.
  • Place monitors at the same height.
  • Use monitors that are the same size and resolution to minimize eye strain.
  • Adjust lighting to minimize glare on screen.
  • Consider the space taken up by the monitors is wider and adjust workspace accordingly.
  • Primary Monitor
    • Primary monitor and keyboard should be placed in from of the user.
    • Secondary monitor should be on a 30 degree angle and the centre of the keyboard no more than 12 inches from the centre line of the monitor
  • Equal use
    • Centre the keyboard in front of the user.
    • Set monitors next to each other and aligned with the keyboard.

Altering Your Display Properties

  • People lean forward or squint their eyes when the font on the screen is too small to read. Here are some tricks to help with posture and reading.
  • To quickly increase the font size when working in a program like Microsoft Word or reviewing a web site click the control button and use the scroll wheel on your mouse.
  • Increasing the font size in Windows will increase the size of all programs, icons and fonts. Adjust the font to a size where you can read it comfortably while seated all the way back in your chair.

Keyboard, Mouse and other Accessories

  • When using your keyboard, upper arms should be relaxed and at your sides
  • Elbows should be bent at a 90° angle.
  • Wrist should be straight.
  • Keyboard should lie flat or have a slight negative incline (tilted keyboard should be on same plane as forearms).
  • Do not use keyboard feet.
  • Wrist rests are used to keep the wrist in a neutral position.
  • Wrist should not be placed directly on the wrist rest since this will cause pressure and potential injury.
  • Placing palms on the rest can cause the wrist to be in an extended posture and can cause fingers to be overworked and overextended.
  • A mouse is an important tool for any computer task
  • You mouse needs to fit your hand so that your fingers are not pinching or spreading
  • Your mouse should be at the same level as the keyboard
  • Individuals should consider mousing with both hands to strengthen muscles and prevent injury
  • Wrist and hand must be kept in a neutral position

Alternate Types of Computer Mice

  • Track ball mouse
    • Reduces wrist movement and allows for movement from fingers
  • Vertical Mouse
    • Rotates the wrist into a more natural posture, reduces contact stress and allows movement from the elbow
  • Ambidextrous Mouse
    • Allows the non-dominant hand to use the mouse.
    • Keeps the mouse in front of the user so there is no movement of the shoulder and arm.

Increasing Your Mouse Pointer Speed

  • Repetitive movement of the mouse can increase strains on the wrists. Increasing the mouse sensitivity will increase the movement per stroke.
  • Click Start (Windows Logo)
  • In the Search Box, type in "Mouse" and select the mouse options
  • On the top taps, click on the tab labeled "Pointer Options"
  • Increase the pointer speed by moving it right into the "Fast" section

Phone and Web Conferencing

  • Keep your phone in a location where it is easy to reach.
  • Try not to reach across your body to answer the phone.
  • Do not cradle the phone on your shoulder and complete other tasks as this causes you to raise your shoulder and bend your neck in an awkward posture.
  • If you need to use your keyboard while talking on the phone consider using a headset or speaker phone to avoid awkwardly positioning your neck.

Organizing Your Workstation

  • Materials used frequently should be located within easy reach.
  • By keeping materials you do not use frequently out of reach, you will have to get out of your chair for them.
  • This will promote blood circulation and reduce overall discomfort.

Task Variety and Ergonomic Breaks

  • It is important to include a variety of tasks in the design of the work completed by an individual in an office setting.
  • This is achieved by mixing intensive keyboarding with other types of computer use and other related materials handling.
  • Tasks should involve a change in posture, i.e. walking to the copier, filing, talking on the phone.
  • Taking rest or work breaks as well as defined breaks such as lunch need to be incorporated into the day.
  • Frequent short pauses are preferable to infrequent longer pauses.
  • A 5–minute break away from intensive computer operation in each hour is encouraged as a good practice and it is open to inspectors to consider that this represents a reasonable precaution to protect the health and safety of workers.

Office Stretches - Get Up and Move

  • Office exercises can be done during short breaks to provide a variety of changes in posture and movement.
  • These exercises can be useful if there are no alternative tasks available.
  • Exercises should not be a primary control. They should be gentle stretches which provide rest for frequently used muscles and movement for muscles that have been static.
  • The best exercise is to get up from a seated position and move around.

Follow Up

  • MSDs may still be reported even after a control has been put in place since it takes time to develop an MSD and new cases can result from exposures and hazards that have since been controlled.
  • What should we do?
  • Ongoing monitoring by supervisors and Joint Health and Safety Committee members
  • Continually encourage worker input to ensure that concerns or comments regarding change are communicated. Workers need to identify concerns to their supervisors as soon as they are identified.

Resources

Ministry of Labour https://www.labour.gov.on.ca/english/hs/topics/pains.php

Occupational Health Clinics for Ontario Workers Inc. http://www.ohcow.on.ca/resources.html

Canadian Centre for Occupational Health & Safety (CCOHS) http://www.ccohs.ca/topics/hazards/ergonomic/

Musculoskeletal Disorders Prevention Series – MSD Prevention Toolbox https://www.iwh.on.ca/msd-tool-kit

 

Updated: 2021-12-04

 
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