Slippery footing
MSD Hazard Control
Methods
Ergonomics Engineering Controls, where feasible, are
the preferred method for controlling MSD hazards. Engineering controls are the
physical changes to jobs that control exposure to MSD hazards. Engineering
controls act on the source of the hazard and control employee exposure to the
hazard without relying on the employee to take self-protective action or
intervention. Examples of ergonomics engineering controls for MSD hazards include changing,
modifying or redesigning the following:
Workstations
Tools
Facilities
Equipment
Materials
Processes
Ergonomics Work Practice Controls are controls that
reduce the likelihood of exposure to MSD hazards through alteration of the
manner in which a job or physical work activities are performed. Work practice
controls also act on the source of the hazard. However, instead of physical
changes to the workstation or equipment, the protection work practice controls
provide is based upon the behavior of managers, supervisors and employees to
follow proper work methods. Work practice controls include procedures for safe
and proper work that are understood and followed by managers, supervisors and
employees. Examples of work practice controls for improper ergonomics MSD hazards include:
Safe and proper work techniques
and procedures that are understood and followed by managers, supervisors and
employees.
Conditioning period for new or
reassigned employees.
Training in the recognition of MSS
hazards and work techniques that can reduce exposure or ease task demands and
burdens.
Administrative Controls
are procedures and methods, typically instituted by the
employer, that significantly reduce daily exposure to MSD hazards by altering
the way in which work is performed. Examples of administrative controls for MSD
hazards from improper ergonomics include:
Employee rotation
Job task enlargement
Adjustment of work pace (e.g., slower pace)
Redesign of work methods
Alternative tasks
Rest breaks
Environmental
Ergonomics Factors
Heat/Cold:
Excessive heat and humidity effects the body's blood
circulation and causes cramps, burns/rashes and general
discomfort. Cold exposures also effects the body's blood
circulation and causes hypothermia, loss of flexibility,
distraction and poor dexterity. A generally comfortable
temperature range is 68 to 74 degrees Fahrenheit -
+/-10 degrees depending on the physical work load - with
humidity between 20 to 60 percent.
Noise
Level/Peaks: Excessive noise levels above 90 decibels (dBA)
and noise peaks above 100 decibels (dBA) cause headaches and
increases blood pressure, muscle tension and fatigue. High
exposure over a long period of time causes deafness and
other audiological disorders. Short term exposure causes
irritability and distraction.
Illumination:
Under-and over-lighted areas causes headaches, muscle
strains, fatigue and eye injury. It effects the body by
reduced visual acuity, distractions, and glare interference.
Poorly lighted areas also provides an atmosphere for
trip/fall hazards and poor coordination.
Illumination is
measured with a light meter, similar to that used by a
photographer.
Recommended illumination (measured in foot-candles) by job
type:
Job Foot-candles
Ergonomics Vibration:
Excessive vibration causes pain to muscles, joints and
internal organs; causes nausea and trauma to the hands,
arms, feet and legs. Vibration is measured by its direction,
acceleration and frequency on the body.
Ergonomics Environment:
Otherwise known as work stress, included in this category
are salary administration, job positions, rest breaks,
Employee attitude, and boredom. Keeping the Employment
Environment up-beat is difficult; however, light colored,
well lighted, un-crowded and clean areas provide a positive
environment. Employees should rest often depending on their
work activity and temperature. Keeping the job moving and variation in
activity reduces boredom.
Ergonomics Work Station Design
Using an old
rule-of-thumb, if we try to design something that everyone
can use, no one will be able to use it. The same principal
holds true with ergonomic work station design. The idea of
ergonomic work station design is to make it fit the user. It
will have to be adjustable for many body heights, sizes,
weights and reaches whether sitting or standing.
One of the first
principals in Work Station Design is to consider the tallest
Employee and the Employee with the shortest reach. The
reason being is that we can not shorten an Employee's height
or lengthen an Employee's reach. Platforms can be used to
raise shorter Employees to the proper work height. Either
sitting or standing, the Employee should be comfortable at
his work station. The arms should rest at the Employees
sides and the Employees back/neck should be kept straight;
therefore, the work level must be waist-high.
Standing in one
place for prolonged periods may lead to a host of injuries.
Sit/stand work stations should be considered. If an Employee
has to stand, providing something to lean on so the Employee
will have the opportunity to rest. Also, providing a heavy
rubber pad to stand on will help relieve neck, shoulder,
back, and leg stress.
Some common injury
prone positions with the body effect are as follows:
Work Position
Body Effect
Standing in one
place
Varicose veins, back stress pooling of blood in legs
Sitting without
back
support
Low back stress
Chair too
high
Decreased circulation, (legs dangling over end) bruises
Shoulders
rounded
Upper/lower back stress, respiratory distress.
Leaning
forward
Lower back stress
Arms
extended/over-reaching
Stress to arm muscles, upper back stress
Elbows
"winged"
Joint stress at shoulder, poor use of bicep muscles
Stepping
backwards
Loss of balance, displaced gravity, muscle stress
Locking
knees
Stress to back of knee, poor blood circulation
With casual
observation of work stations, each of these injury prone
positions can be eliminated. Almost anytime an Employee has
to raise a foot off of the floor to reach a moving or
stationary object, they are hyper-extending and are in an
injury prone position.
Ergonomics Material Movement
To start, ask this
question: "How many times does an Employee have
to pick up and carry raw or in-process product before its
ready to go out the back door?". Each time product is
moved from one work level to another, the chances of back,
neck and shoulder injury and a host of repetitive motion
disorders are greatly increased. Conveyor lines, bins and
shackle lines should be at the same level as the work
station (Approximately waist high). Conveyor lines, carts, trolleys, lifts or other
mechanical means should be considered whenever boxes of
product are moved from one point to another by an employee.
Proper ergonomics lifting techniques and engineering controls can be
used to prevent back injuries.
Ergonomics Tool Design
The last area of
work station design is tool design. Many manufacturers are
marketing tools that are "ergonomically designed".
However, just because a tool is ergonomically designed, it
may do more harm than good. In many
cases, just changing the way a toll is used may
be and effective ergonomics solution.
Tools should be
designed, modified or used in a manner which allows the hand
to rest in a near neutral position. In some cases, heavy
tools will need to be suspended from above, so the bulk of
the weight is not supported by the Employee's hands/arm. The
handles of the tool should extend the full length of the
palm, be soft/shock-resistant and large enough to be easily
gripped. Trigger activated tools should be modified to allow
multi finger operation which prevents the full required
activation force from being applied by only one finger.
More detailed information on
Ergonomics
& Material Handling
can be found in the Members Area