Computer Workstation Ergonomics

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Computer Workstation Ergonomics

• For Use by UMKC Employees

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Ergonomics

• Ergonomics can be described as the study of
  adapting the environment to the individual.
• The aim of ergonomics is to reduce the amount of
  physical stress caused by improper body
  mechanics, repetitive motor movements, static
  positions, vibrations, lighting and impact or
  contact with objects.

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• To modify our environment properly we first need
  to identify the sources of physical stress at the
  computer work station.

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The Eyes

• As we get older we tend to be more comfortable
  focusing on objects further away.
• While focusing on the monitor, we tend to blink
  less, causing the eyes to dry out. This is
  especially critical for those who wear contact
  lenses.
• Glare or dirt on the screen makes it difficult to
  focus and causes additional eye strain.

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Static Positions

• Static sitting positions, especially when coupled
  with poor body mechanics, can cause stress to the
  back, neck, shoulders and legs.

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Repetitive Motion

• Repetitive fine motor movements related to
  keyboarding have been associated with certain
  medical conditions involving the hands, wrists,
  thumbs and fingers.
• Thresholds vary greatly between individuals
  before pain or injury takes place, thus
  contributing to a sense of complacency among some
  workers.
• Workers should also examine activities outside of
  the work environment when trying to limit
  repetitive stress. Activities such as knitting,
  playing musical instruments, painting and other
  activities may also contribute to the total load
  of repetitive motion.

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Contact with Objects

• Highly localized pressure caused by an object
  against the body can cause numbness and loss of
  blood circulation. Common examples are across
  the back of the legs from the edge of a chair,
  across the forearms or at the elbows from leaning
  on a table or desk, and on the inside of the
  wrists from leaning on them while keyboarding.

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Poor Body Mechanics

• Awkward body positions can amplify stress caused
  by repetitive motion, static positions and
  pressure contacts with objects.

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Intervention Strategies

• Periodic mini-breaks from repetitive movements
  allow the body to recuperate. Work does not have
  to stop. Rather, identify duties that do not
  require the same type of effort and take a break
  by doing something different.
• A kitchen timer can be used as a reminder to take
  a mini-break.

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Intervention Strategies

• For dry eyes, use an over-the-counter eye
  lubricant (sometimes known as artificial tears).
  Dont wait until your eyes begin to burn, apply
  the eye drops each time you take a mini-break.
  Avoid using eye drops that get the red out.
  Prolonged use of this type of eye drop can cause
  damage to the eye.

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Intervention Strategies

• For those having difficulty seeing the monitor
  screen with bi-focal or tri-focal lenses, speak
  with your optometrist about a pair of single
  vision lenses for use at the computer. Take a
  measurement from the bridge of your nose to the
  top line of the monitor screen. Give this
  information to your eye doctor.

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Intervention Strategies

• Proper posture and body mechanics can reduce the
  amount of physical stress. At the keyboard
  adjustment of the seat height, lumbar support,
  monitor height, monitor distance, and mouse
  placement encourage good posture and proper
  positioning of the hand and wrists.

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Intervention Strategies

• If you regularly enter information while on the
  telephone, consider a speaker phone or headset
  telephone. Never cradle the phone between your
  shoulder and ear.

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Making the Adjustments

• First, adjust the chair height so that you can
  reach the keyboard with the upper arms falling
  naturally by your side and with your forearm and
  upper arm forming a right angle.

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Making the Adjustments

• Adjust the lumbar support so that it fits into
  the curvature of your back just above the
  buttocks. Some lumbar supports can also be
  adjusted for firmness.

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Making the Adjustments

• The hand should extend straight out from the
  forearm. Place a pencil across the back of the
  hand. The pencil should be able to lie nearly
  flat across the back of the hand. The pencil
  will also help you see if you have the hand
  turned out or inward.

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Making the Adjustments

• This is known as neutral positioning of the
  hand. This position allows for the greatest
  amount of room for tendons and the median nerve
  that run through the carpal tunnel in your wrist.

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Making the Adjustments

• The mouse should be placed as close to the
  keyboard as possible. Mouse platforms are
  available that straddle the far right side of the
  keyboard. For those who do not use the numeric
  keypad, this may be a viable option. Move the
  mouse by using your whole arm, not just your
  wrist.

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Making the Adjustments

• For those with normal vision, the monitor
  should be between 18 and 24 from your eyes.
  Those with single vision glasses, adjust the
  distance to your comfort. The top line of the
  monitor should be at the same height as your
  eyes. The monitor should be tilted back slightly
  (about 15 degrees from vertical).

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Making the Adjustments

• Those with bi-focal or tri-focal glasses must
  approach monitor adjustment differently.

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Making the Adjustments

• First, lower your head forward. Slowly raise
  your head until very little effort is required to
  hold your head in position.

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Making the Adjustments

• Then, position the monitor height and distance so
  that you can see the monitor through the
  appropriate lens while your head is in the low
  effort position.

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Making the Adjustments

• If you key from hard copy material, use a
  swing-arm copy holder or position your easel so
  that the hard copy material is at the same
  height and distance as your monitor.

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Making the Adjustments

• Do not place the hard copy material on the flat
  desk and twist your neck so that you can read.

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Making the Adjustments

• It is important to have your feet placed flat on
  the floor. With your feet flat on the floor you
  are anchored. This allows you to push off,
  keeping your torso up-right so as to avoid
  slouching or reclining. If necessary, use a foot
  rest to provide this support.

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Making the Adjustments

• Glare on the monitor screen can be eliminated by
  use of drapes, placing the screen at a 90 degree
  angle from the light source and use of a glare
  hood or glare screen. Avoiding light colored
  clothes that may reflect in the screen can also
  help. Keep the screen clean.

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Purchasing Decisions

• The chair is one of your most important ergonomic
  purchases. The comfort and adjustability of your
  chair will affect your entire posture and body
  mechanics.

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Purchasing Decisions

• The seat pan should have a waterfall front
  edge.
• Adjustments for both seat height and lumbar
  support should be simple and easy to get to.
• Avoid arm rests. Most are not well designed and
  they tend to make it difficult to pull up close
  to the desk.
• The chair should have 5 casters for ease of
  movement and stability.
• The casters should be designed for the type of
  floor surface on which they will roll.

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Purchasing Decisions

• The more you look at the monitor while computing,
  the more you should consider a larger monitor.
  The price differential between a 15 monitor and
  17 monitor is quite small when compared to the
  overall cost of a personal computer. Pixel size
  also will affect the clarity of the screen
  images. Smaller pixels greater clarity.

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Purchasing Decisions

• In order to raise the monitor height, you can use
  telephone books or other things around the office
  to create a raised platform. There are also
  inexpensive devices that can create a raised
  platform with some offering storage for
  diskettes, paper or other supplies you might want
  to keep at hand.

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Purchasing Decisions

• The cost of split keyboards is now comparable to
  the cost of replacement keyboards. The broader
  your shoulders are the more difficult it is to
  maintain your hands and wrists in neutral
  position. Split keyboards help some to attain
  neutral positioning and reduce the micro
  traumas associated with keyboarding.

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Purchasing Decisions

• If you have a computer workstation that will be
  used by multiple people, an easily adjustable
  chair is a must. You should also consider a
  height adjustable table or a keyboard tray that
  is height adjustable.

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Treatment of Repetitive Stress Injuries

• Do not try to self treat by purchasing over the
  counter wrist splints. Wrist splints are also
  known as occupational splits and are designed for
  specific occupational duties. Splints should be
  fitted by a physician and are often used in
  conjunction with medication. Early appropriate
  treatment is important to avoid long term
  physical damage.

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Treatment of Repetitive Stress Injuries

• If you believe that you are experiencing a
  repetitive stress injury due to your work or if
  your physician indicates that you have a medical
  condition that is as a result of your work, you
  should report this to your supervisor
  immediately. Your supervisor should complete a
  UMKC Report of Employee Injury form.

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Review

• The back should be vertical with the shoulders
  positioned over the hips.
• Support should be given to the lumbar curve in
  the spine.
• The head should be positioned so that it rests
  comfortably over the spinal column. Little
  effort should be necessary to maintain the
  position.
• The monitor and hard copy should be placed
  directly in front of you.

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Review

• The upper arms should hang naturally at your
  side. Pull your chair up close to the keyboard
  so that you can avoid reaching out for the
  keyboard.
• The forearms and the upper arms should form a
  right angle.
• Your hands and wrists should be in neutral
  position.
• Hips should be against the back of the seat.
• Feet should be flat on the floor, not stretched
  out or wrapped under.

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