Office Ergonomics/Safety Pamela A. Boatright System Safety, Health & Environment Resource Center Oklahoma State Regents for Higher Education
Dec 26, 2015
Office Ergonomics/Safety
Pamela A. BoatrightSystem Safety, Health & Environment Resource CenterOklahoma 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 Chair Characteristics Keyboard and Mouse Monitor Position Glare Document Position Telephone Use Work Behavior
Chair Position Back straight Head upright Fully supported S-
curve in spine Wrists straight Hips, knees and
elbows at 90° Feet and arms
supported
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
Keyboard and Mouse Position
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.
About 2-3” lower than desk height
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.
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.
Alternative Pointing Devices
Good Working Positions | Workstation Components | ChecklistsGood 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 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
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.
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 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.
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
Place palms over closed eyes and relax Focus on far away objects - “20/20 Rule”
Change tasks and/or position every 20 - 30 minutes. 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 Assessment
Limited space on the work surface may cause users to place components and devices in undesirable positions.
Workstation Assessment Monitor too low Mouse position Keyboard position No arm rests Document holder
good
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 InstituteOrthopaedic & Reconstructive Center
1044 SW 44th StreetOklahoma City, OK 73109
405/631-4263
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.
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/
computerworkstations/index.html http://www.osha.gov/SLTC/etools/
computerworkstations/positions.html http://www.osha.gov/SLTC/etools/
computerworkstations/checklist.html http://www.osha.gov/SLTC/etools/
computerworkstations/wkstation_enviro.html
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.
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.