SECTION 7: Ergonomics
Ergonomics is the science of designing work areas or equipment for safe,
comfortable and effective human use. Certain laboratory related tasks
may place lab workers at an increased risk for developing repetitive strain
injuries (RSI). Repetitive activities may cause discomfort and, if not
properly modified, may lead to pain or reduced dexterity.
Not everyone performing the same job tasks will develop a RSI. Listed
below are the most common factors that may increase the risk for a RSI:
- Awkward Body Postures: Any posture that
places a body part out of a neutral position (i.e. twisting, poor
bending, over-reaching) may put increased strain on muscles, tendons,
ligaments and joints.
- Exertion: Maintaining a specific body position
or exertion for long periods of time may result in pressure or force
being placed on the soft tissues.
- Repetition: Higher numbers of similar body
movements over extended time periods may increase the risk of developing
- Contact Pressure: Pressure resulting from
leaning against or resting a body part on a sharp edge or hard surface
can constrict blood flow.
Laboratory procedures may be repetitive or involve a variety of these
Certain laboratory procedures require frequent pipetting for extended
periods of time, resulting in repetitive force on the thumbs, hands,
forearm, or fingers. Stresses may be reduced by varying pipetting with
other lab tasks that use different motions and muscle groups or by taking
frequent, small rest breaks. Place receptacles for used pipette tips
close to the work area to avoid frequent reaching. If it is an option,
replace manually operated pipettes with electronic ones for larger workloads.
Biological Safety Cabinets/Fume Hoods
Working in Biological Safety Cabinets (BSCs) or chemical fume hoods
may require lab workers to bend forward frequently or assume awkward
body postures. Users should take short breaks to alter their body posture,
or to reduce contact pressure caused by leaning on sharp edges or hard
surfaces. Keeping the viewing window of hood clean, and line of sight
unobstructed, reduces eye strain and the need to assume awkward body
Operating a microscope for long hours may put increased strain on the
neck, shoulders, eyes, lower back, arms and wrists. If sitting, use
an adjustable chair that provides support to the back and legs. Ensure
that your feet are flat on the floor or supported by a footrest. Avoid
raising your shoulders and bending your neck for long periods of time
while looking through the microscope’s eyepiece. Position the
microscope as close as possible to reduce the need to bend forward.
Take adequate small breaks, or vary microscopy with other job tasks.
Computer Workstations (top)
The following guidelines are intended to help workers understand and
reduce health risks associated with computer workstations:
- The keyboard and mouse should be directly in front of the operator
at a height that favors a neutral posture. The objective is a posture
with upper arms relaxed and wrists straight in line with the forearm.
- The monitor should be positioned at a distance of approximately
arm’s length and directly in front of the operator. The top
of the screen should be no higher than eye level.
- A well designed chair will favorably affect posture, circulation,
the amount of effort required to maintain good posture, and the amount
of strain on the back. An adjustable seat back is best for support
of the lumbar region. The user should be able to adjust seat height
and seat pan angle from a seated position.
- Additional accessories may improve operator comfort. Document holders
may minimize eye, neck and shoulder strain by positioning the document
close to the monitor. A footrest should be used where the feet cannot
be placed firmly on the floor. Task lamps should be used to illuminate
source documents when room lighting is reduced.