Ergonomics is defined as the study of workplace equipment design or how to
arrange and design devices, machines, or workspace so that people and things
interact safely and most efficiently. Ergonomics is also called
human-factors analysis or human-factors engineering. Ergonomic design
facilitates harmony between the person and person's work environment by
addressing individual needs and characteristics, and by positioning the body
so there is less stress and strain on it while performing required tasks.
When adjusting office furnishings and equipment, focus on the optimal "fit"
between work environment and individual work style.
Since a poorly-designed workstation can slow staff down, increase their
stress, and contribute to chronic conditions such as carpal tunnel syndrome,
it is important each person organizes workspace to keep twists, turns and
uncomfortable movements to an absolute minimum. Be sure that they have
enough desk space to comfortably accommodate the materials and equipment
that are part of their jobs; i.e., books, papers, calculators, and
computers, and keep the items they use most frequently use closer to them.
Failure to pay attention to ergonomic issues can result in a wide array of
workplace injuries, some permanently debilitating. Examples of injuries
- Potential strains and sprains?A poorly-designed workstation can result in
twists, turns and uncomfortable movements. Ensure that there is enough desk
space to comfortably accommodate the materials and equipment that are part
of the job: books, papers, calculators, computers and printers.
- Injuries sustained while lifting and stretching?Lifting heavy objects can
cause serious injuries, but failing to lift objects of any weight properly
can result in injury. Workers need to be taught the proper methods for
lifting and stretching whether it's a service recipient, a carton of books
- Repetitive injury due to improperly adjusted computer workstations, chairs
and desks?Individuals can sustain repetitive injuries by working at computer
workstations that are not properly adjusted. Repetitive injuries are
particularly chronic problems that could result in permanent disability.
Guidelines for Workstations
- Ensure that workstations are adjusted to meet the needs of the user.
- Provide for adequate leg-room of 3-to-6 inches from the top of the user's
thigh to the desk surface.
- Cut back on office noise by covering noisy printers and turning down
ringers on phones, fax machines, network servers and people's personal
- Glare and intense lighting are not always easy to eliminate and can cause
eyestrain and headaches. Sometimes turning off the overhead fluorescent
lighting and providing surface lighting will help, or move the computer
monitor to another location to avoid direct glare from windows or overhead
lighting or try an anti-glare screen.
The body should be in the following position when using a computer:
- Wrists straight
- Forearms supported
- Back supported
- Forearms parallel to the floor
- Thighs parallel to the floor
- Feet on the floor or a foot rest
- Top of monitor at or slightly below eye level
The height of the work surface is an important aspect of a good ergonomic
workstation. The computer work surface should adhere to the following
- The proper height for a computer work surface is about 3 or 4 inches lower
than the average writing desk.
- The work surface should be positioned so that the user's forearms are
parallel to the floor. The user's elbow should make an angle of between 90
and 110 degrees.
- The work surface should be positioned so that the user's forearms are
supported a minimum of 6 inches.
- The work surface should be positioned so that the user's wrists can be
straight and neutral. Wrists bent in any direction (up, down, left, or
right) may lead to discomfort and eventually injury.
Guidelines for Chair Adjustment
- Workers should adjust chair height should allow their forearms to be
parallel to the floor, feet to be flat on the floor or on a footrest, and
thighs to be parallel to the floor.
- Back supports should be adjusted so that the curve of the back of the seat
is in the curve of the lower back. Provide a towel or a lumbar pad if the
chair does not provide adequate support.
- The chair's backrest should be adjusted for seat pan clearance. The worker
should be able to place 2 or 3 fingers between the back of his/her knees and
the front edge of the seat.
Position the computer monitor according to these guidelines:
- Place the monitor directly in front of the user.
- Don't position the monitor
where the user would have to twist his/her neck.
Lifting and Stretching
Although a typical office job may not involve lifting large or especially
heavy objects, it's important that workers follow the principles of safe
lifting. Small, light loads (i.e., stacks of files, boxes of computer paper,
books) can wreak havoc on their backs, necks, and shoulders if they use
their bodies incorrectly when they lift them. Backs are especially
vulnerable; most back injuries result from improper lifting.
Posture affects which muscle groups are active during physical activity.
Awkward postures can make work tasks more physically demanding by increasing
the exertion required from smaller muscle groups and preventing the
stronger, larger muscle groups from working at maximum efficiency. The
increased exertion from the weaker, smaller muscle groups impairs blood flow
and increases the rate of fatigue.
Encourage a midrange, comfortable posture by ensuring that materials, tools,
and equipment for all work activities (excluding lifting tasks) are kept in
the "general safety zone" (between the hips and shoulders and close to the
body). Lifting tasks should be performed within the ?lifting safety zone?
(between the knuckles and mid-chest and close to the body). Recovery periods
(i.e., muscle-relaxation breaks) can help prevent the accumulation of
fatigue and injury to muscles and their associated structures. Try to break
up work with frequent, short recovery periods. Even recovery periods as
short as a few seconds on a regular basis are helpful.
Modifying work practices
Pay close attention to how the work is being performed. Our bodies are
stronger, more efficient, and less injury prone when we work in midrange
postures. Maintaining midrange working postures simply means sitting or
standing upright and not bending the joints into extreme positions. This can
be done by trying to keep the neck, back, arms, and wrists within a range of
neutral positions. Employees should be encouraged to be comfortable, to
change positions, and to stretch when working.
Guidelines for Safe Lifting
- Instruct workers to take a balanced stance, feet placed shoulder-width
- When lifting something from the floor, have them squat close to the load.
- Educate workers to keep their backs in its neutral or straight position.
Have them tuck in their chins so heads and necks continue the straight back
- Show workers how to grip the object with their whole hands, rather than
only with their fingers.
- Have them practice drawing the object close to their bodies, holding their elbows close to their bodies to keep the load
and your body weight centered.
- Tell workers to lift by straightening their legs. Have them practice under
supervision letting their leg muscles, not back muscles, do the work. Tell
them to tighten stomach muscles to help support the back and maintain a
neutral back position as they lift.
- Instruct workers never to twist when lifting. When turning with a load,
show them how to turn their whole body, feet first.
- Tell workers never carry a load that blocks their vision.
- To set something down, workers will use the same body mechanics designed
Lifting From a Seated Position
- Bending from a seated position and then straightening up places tremendous
strain on a staff member's back. An unstable chair could slip out from under
the person. Instead, have the person stand and move the chair out of the
way, then squat and stand whenever retrieving something from the floor.
- If a volunteer or employee is doing a lot of twisting while lifting, try to
rearrange the space to avoid this.
- Staff members who have to twist under a load are more likely to suffer back
- Rotate staff members through tasks so that periods of standing alternate
with moving or sitting.
- Provide stools or footrests for stationary jobs.
- Store materials at knee level whenever possible instead of on the floor.
Make shelves shallower (12-18") so employees and volunteers do not have to
reach forward to lift the object. Break up loads so each weighs less.
- If a staff member must carry a heavy object some distance, consider storing
it closer, requesting a table to rest it on, or provide a hand truck or cart
to transport it.
Creating a Healthy Computer Workstation Environment
See OSHA e-tool
FEOSH — Department of Energy
ISO 9241, Ergonomics Requirements for Office work with Visual Display
Terminals (VDTs): Part 5: Workstation Layout and Postural Requirements.
International Organization for Standardization, Geneva, Switzerland
Office of Health and Safety,
Centers for Disease Control and Prevention
Safe Lifting and Stretching Checklist
Safe Workstation Checklist
Lifting and Carrying Tips for Employees and Volunteers
Setting up an Ergonomically Sound Office Space