Transcript Document
Office Ergonomics/Safety
Pamela A. Boatright
System Safety, Health & Environment Resource Center
Oklahoma State Regents for Higher Education
Ergonomic Regulations
OSHA published a draft ergonomic
standard, but it was not approved.
However, the OSHA “General Duty
Clause” requires employers to provide a
safe and healthy working environment
for employees.
OSRHE Guidelines (4/98)
Ergonomics
The study of the relationship between
man and machine.
When the body is required to perform
repetitive motion, work in an awkward
position, or repeatedly lift heavy
objects, injuries may develop.
When employees are comfortable they
are more productive.
Risk Factors
Repetitive activity
Holding a position without movement
Use of force or strength
Localized pressure
Awkward positions
(Low temperature)
(Vibration)
Repetitive Activity
Open letters
Stapling
Flipping through files
Sorting letters
Keyboard
Computer vs. typewriter
Holding Position w/o Movement
Reduces blood flow
Fatigue
Work demands
Gripping mouse too tightly
Holding phone to ear
Excessive Use of Force
Typist – up to 10,000 impacts per
day
People diagnosed with carpal
tunnel use 18% more force to do
a task
Excessive Use of Force
Stapling
Stamping
Grasping large folders or books
Lifting files/books
Pushing/pulling heavy file drawer
Chair “scooting”
Localized Pressure
Sharp edges
Keyboard corners
Work surface corners
Hard or angular chair arm rests
Awkward Positions
Press on nerves, stretch tendons
Shoulder and phone
Elbow and phone
Poor neck postures, movements
Leaning, reaching for tools (10-key,
printer, stapler, etc.)
Awkward Positions, Wrist
Bending up, down, side-to-side
Inappropriate keyboard height
Inappropriate keyboard angle
No support for resting hands
Splayed elbows
Faulty keyboarding/mouse habits
Neutral Body Posture
Places the least amount of stress
on the body
Physical stress is evenly
distributed
“Zero gravity posture”
“Neutral position”
Neutral Body Posture
Straight back
90° hip bend
90° knee bend
Straight head/neck
Relaxed shoulders
90° elbow bend
Straight wrists
Upright sitting posture
The torso and neck are
approximately vertical
and in-line
The thighs are
approximately
horizontal
The lower legs are
vertical
Declined sitting posture
Thighs are inclined
The angle between the
thighs and the torso is
greater than 90
degrees.
Torso is vertical or
slightly reclined and the
legs are vertical.
Standing posture
The legs, torso, neck,
and head are
approximately in-line
and vertical.
The user may also
elevate one foot on a
rest while in this
posture.
MSDs
Carpal Tunnel
Guyon’s Canal
Epicondylitis
Reynaud’s
Thoraic Outlet
Muscle Strains
Ganglion Cysts
Tendonitis
Tenosynovitis
DeQuervain’s
Trigger Finger
Back Pain
Carpal Tunnel
The channel found in the wrist
surrounded by bones and a non-elastic
ligament.
Several blood vessels, nine tendons,
and the median nerve all pass through
this channel from the forearm into the
hand.
Carpal Tunnel
Certain movements, especially repeated
movements and bent wrists, can cause
an increase in pressure in the carpal
tunnel.
Symptoms can include tingling,
numbness, pain, swelling, and burning
sensation in the hand.
1-2 per 1000
Workstation Configuration
Workstation Configuration
Chair Characteristics
Keyboard and Mouse
Monitor Position
Glare
Document Position
Telephone Use
Work Behavior
Chairs
Chair Position
Back straight
Head upright
Fully supported S-curve
in spine
Wrists straight
Hips, knees and elbows
at 90°
Feet and arms
supported
Examples of Good Chairs
Chair Characteristics
Back rest covers from hip to upper back
Contoured and padded seat and
backrest
Waterfall seat design
Five casters for stability
Chair Adjustability
Seat height
Seat depth
Tilt tension
Back height
Arm height
see slide out card under chairs, left
forward side
Examples of Poor Chairs
Bad and Ugly Too!
Keyboards/Point Devices
Keyboard and Mouse Position
About 2-3” lower than
desk height
If you can’t lower the keyboard, you may
consider raising your chair.
Center the alphabetical section to your body.
Keep the keyboard flat.
Rest wrists on rest pad only when not typing.
Place the mouse next to the keyboard.
Keyboard Positioning
Place the keyboard directly in
front of you at a distance that
allows your elbows to stay
close to your body with your
forearms approximately
parallel with the floor.
A keyboard tray may be useful
if you have limited desk space
or if your chair has armrests
that interfere with adequate
positioning.
Wrist Rest Placement
Your hands should move freely and be
elevated above the wrist/palm rest while
typing.
When resting, the pad should contact the
heel or palm of your hand, not your
wrist.
Wrist Rest Placement
Some desks and
computer equipment
have hard, angled
leading edges.
This can affect nerves
and blood vessels,
possibly causing tingling
and sore fingers.
Typical Keyboards/Trays
Keyboard Tray
Tilt 0° to -15°
No + tilt angle
Height Adjusts
6 1/4“
Base Swivel
Locks
Alternative Keyboards
Keyboard Placement
Alternative keyboards help maintain neutral
wrist postures, but available research does
not provide conclusive evidence that using
these keyboards prevents discomfort or
injury.
Pointing Devices
Improper Mouse Placement
Mouse Wrist Rest
Alternative Pointing Devices
Good Working Positions
|
Workstation Components
Checklists
|
Adjusting Computer Pointer
Sensitivity and speed should feel comfortable.
The pointer should be able to cover the full
screen while the wrist is maintained in a
straight, neutral posture.
Sensitivity should be set so you can control
the pointing device with a light touch.
Most devices can be adjusted through the
computer control panel.
Avoid tightly gripping the mouse or pointing
device.
Monitor Position
Monitor Position
Monitor in front of the
keyboard, not to side
Top of monitor at eye level
Arm’s length away (24-30”
approx.)
Up to 10° backward tilt or
flat
Text size may need to be
increased for smaller
monitors.
Monitor Position
The top of the
monitor should be at
or slightly below eye
level.
The center of the
computer monitor
should normally be
located 15 to 20
degrees below
horizontal eye level
Monitor Position
Monitor blocks are
simple and
inexpensive.
Telephone books
are cheaper.
Monitor Position
Bifocal Wearers
Bifocal users typically view the monitor
through the bottom portion of their lenses.
This causes them to tilt the head backward to
see a monitor that may otherwise be
appropriately placed.
As with a monitor that is too high, this can
fatigue muscles that support the head.
Monitor Tilt
Monitors that are tilted significantly either
toward or away from the operator may distort
objects on the screen, making them difficult
to read.
When the monitor is tilted back, overhead
lights may create glare on the screen. This
can result in eyestrain and sitting in awkward
postures to avoid eye glare.
Monitor Solutions
Lower the monitor so you can maintain
appropriate neck postures.
You may need to tilt the monitor screen up.
Raise chair height until you can view the
monitor without tilting your head back. You
may have to raise the keyboard and use a
foot rest.
Use a pair of single-vision lenses designed for
computer work.
Other Monitor Considerations
Adjust brightness as needed.
Keep the screen clean.
Glare
Glare
Glare may cause eye strain or
headaches.
Position the monitor between
overhead lights and perpendicular to
windows
Select a glare screen for the model
and size of monitor, but only if
needed.
Task lighting on the document should
not cause glare on the monitor.
EMF “radiation” is NOT an issue.
Glare screens
Block up to 99.9%
of ELF/VLF E-field
radiation when
properly grounded
$250
Glare only $130
Document Holders
Document Position
Position documents
next to monitor and at
the same height to
reduce:
Head and neck
movement
Eye refocusing distance
Document Holder
Allows you to place documents at
or about the same height and
distance as the monitor screen.
Should be stable when loaded with
heavier documents such as a
textbook.
Provides a sturdy writing surface, if
written entries are necessary.
Work Zones
Work Zones
The location of frequently-used items should
remain within the primary work zone.
Telephone Use
Telephone Use
Place the telephone in the primary
or secondary work zone, depending
on usage patterns.
Cradling the telephone between your
neck and shoulder creates an
awkward position.
Avoid the shoulder-rest device if at all
possible.
Consider a phone headset instead.
Telephone Quick Tips
Use a speaker
phone or head set
for long
conversations.
Keep it close enough
to avoid repeated
reaching.
Work Behavior
Eye relaxation techniques
Change tasks and/or position every 20 - 30
minutes.
Place palms over closed eyes and relax
Focus on far away objects - “20/20 Rule”
Allows muscles to recuperate from static
positioning
Improves blood flow to extremities
Microbreaks
(do NOT replace regular breaks)
Work Behavior
High repetition tasks or jobs that require long
periods of static posture may require several,
short rest breaks.
Users should stand, stretch, and move
around to provides rest and this allows the
muscles to recover.
Alternate tasks whenever possible, mixing
non-computer-related tasks into the workday.
This encourages body movement and the use
of different muscle groups.
Lift CAREFULLY; never twist and lift
Workstation Assessments
Workstation Assessment
Limited space on the work surface may
cause users to place components and
devices in undesirable positions.
Workstation Assessment
No room for trackball
on keyboard tray
No document holder
No wrist rest
Workstation Assessment
Monitor too low
Mouse position
Keyboard position
No arm rests
Document holder
good
Workstation Assessment
Poor mouse position
No document holder
Workstation Assessment
Monitor and
keyboard too high
No arm support
Document height
too low
Workstation Assessment
Much better !!
Lowered monitor
Raised arm rests
Raised chair
Conclusion
All you need is common sense.
Always work in neutral positions.
Modify the equipment around you, don’t
modify your body posture to fit the
equipment.
Give adjustments a couple of days.
Minimize awkward postures, static
positioning, and repetitive movements.
Workstation Stretches
Developed by Dr. Houshand Seradge, M.D.
The Hand Institute
Orthopaedic & Reconstructive Center
1044 SW 44th Street
Oklahoma City, OK 73109
405/631-4263
Laptop Ergonomic Guidelines
Centers for Disease Control and
Prevention
Laptop Guidelines
The CDC recommends that laptop
computers not be used as a primary
computer at home or at work.
Occasional users should:
Find a comfortable chair
Use a neutral wrist position
Position screen to minimize neck bending
Laptop Guidelines
Consider using an external keyboard or
docking station.
Take mini-breaks ever 20-30 minutes.
Keep viewing distance @18-30 inches.
Position keyboard at elbow height.
If seated in a side-chair or couch, use a pillow
to support your arms while keying.
Clean the screen regularly.
Docking Stations
Transporting the Computer
If computer and accessories > 10 lbs,
consider a bag with wheels.
Eliminate all unnecessary items from
your briefcase.
Carry a laptop in a case with padded
shoulder pad and handle.
Shift hands and shoulders to balance
the load.
Web Resources
http://www.osha.gov/SLTC/etools/comp
uterworkstations/index.html
http://www.osha.gov/SLTC/etools/comp
uterworkstations/positions.html
http://www.osha.gov/SLTC/etools/comp
uterworkstations/checklist.html
http://www.osha.gov/SLTC/etools/comp
uterworkstations/wkstation_enviro.html
Office Safety
Falls
Falls are the most common office
accident.
Clear walking pathway
Close drawers after use
Avoid bending, twisting, leaning while
seated
Secure electrical cords
Struck By or Striking Objects
Bumping into desks, cabinets, open
drawers
Supplies falling out of cabinets or off
shelves
Misbalanced file cabinets
Machines dropped on feet
Doors opening suddenly
Caught In or Between
Fingers caught in drawer, door, or
window
Fingers, hair, clothing, jewelry caught in
machines
Fingers caught under knife or paper
cutter
Safe Office Practices
Use a proper stepladder for overhead
reaching, not rolling chairs or even
padded chairs, please.
Clean up spills immediately, even if they
are not “yours”.
Report loose carpeting, damaged
flooring, lights out, etc.
Office Electrical Safety
Never remove the grounding plug
from any piece of equipment.
Inspect electrical equipment and
electrical cords regularly. Repair or
discard if damaged.
Electrical Cords
Do not drape or pull over nails, hooks,
or other sharp objects.
Extension cords are temporary wiring
only. If a cord must run across a
walkway, tape it or cover it.
Never pull a plug to turn off equipment.
Electrical Cords
Working on “live” equipment
Disconnect electrical machines before
cleaning or adjusting.
If a guard is removed to clean or repair
parts, replace the guard before testing
or putting it back in service.
“Daisy Chain”
Slip, trip, or fall
Electrical Cords
Overloaded Outlets