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Occupational Safety Health (OSHA)

Ergonomics is the study of fitting the
work/job to the individual. Ergonomics
matches the design of tools, controls, and
equipment to fit the safety needs of the
operator. Since each of us has different
needs, ergonomic design of tools,
equipment, and workspaces must be
adjustable enough to accommodate a varied
range of body types.

Derived from two Greek works:
 “Nomoi” meaning natural laws
 “Ergon” meaning work
 Ergonomics addresses the relationship
between people , their tasks , equipment
and work environment
 Hence , ergonomists study human
capabilities in relationship to work
demands…

 In 1857,Wojciech Jastrzebowski created the
word “ergonomics” in a narrative he wrote
about the science of nature.
 World war ll in 1943, an army officer
Alphonse Chapanis, learned that if the
control layout in the cock pits of plane were
simplified, the pilot make fewer errors.

 After world war ll, ergonomics not only
productivity, but also the safety of the
workers.
 Research take place in various area
 The affect of heavy labor on the heart; the
maximum loads that should be pulled ,
pushed or carried
 The amount of muscle force that should be
required to perform

 Work surface  Alternative input
 Sit or stand? devices
 Fitting all the pieces  Monitor basic
together  Telephone basic
 Accepted postured  Source documents
 Sitting basics  Additional accessories
 Work surface basics  Work/rest schedule
 Keyboard / mouse
basic

HEIGHT
 May very depending on task ; e.g surface higher for
writing and typing
 Should not contact the thighs or knees
Width
 Wide enough to accommodate all needed input
devices, task materials and accessories
 Enough clearance for legs and any items stored
below work surface

Depth
 Allow for allow positioning of monitor
 Allow for postural changes
 Knees should not contact items / support
structure under work surface

Sit when
 Doing fine manipulated
 Need high visual attention
 Need high degree of stability
 Precise foot control is needed
 There is not heavy material handling
 Task requires fixed postured for extended
periods

 Frequently handle heavy objects or when
experience heavy downward forces
 Mobility is required
 Frequently need to make extended reaches
 Doing a variety of tasks
 Doing work intermittent work
 Have low back pain

 Seating
 Work surface
 Keyboard
 Monitor
 Telephone
 Additional accessories
 Work/ rest schedule
 Manual material handling

Upright
Thighs
Reclined
Standing
Move throughout these postures

Hips slightly higher than knees
Feet supported
Lumber support below beltline
Back angle upright or slightly reclined
Arms relaxed or supported

 Design must be based on job tasks
 Surfaces should be height adjustable
 Reading/ writing surface 2 inches higher than
elbow height
 Keyboard / mouse surface elbow height

 At or slightly lower than elbow height
 Neutral wrist postures
 Relax shoulders
 Use a light touch

 Splitkeyboard design
 Vertical or concave keyboard design
 Trackball
 Touchpad
 Mouse with a supinated angle
 Always use on a trial basis prior to purchase

25 – 36 inches from eyes
At or slightly lower than eye level
Direct alignment
Avoid glare or contrast from bright light
sources

 Ambient light levels 20-50 foot candles
 Refresh rate 70-80 Hz
 Dark characters on a light background
 Clean monitor at least 1x per week

 Avoid cradling the hand set between your
shoulder and head
 Hold the hand set with your dominate hand
 Use a headset or speaker phone when
appropriate

 Document holder
-adjacent to monitor
-between monitor and monitor
 Reading / writing slope

 Large grip pen/pencil
-decrease stress on muscles/tendons
 Wrist rest
-Use only while pausing between key strokes
 Footrest
-essential when feet do not touch the floor
-help promote postural changes

 Rotate job tasks at least 1x per hour
 Utilize schedule breaks
 Incorporate stretching into daily routine
 Change postures frequently
 Get out of your chair

 Forceful exertions
 Repetitive motions
 Awkward postures
 Static postures
 Compression or contact stress
 Lighting
 Vibration
 Noise
 Cold temperatures

 Forceful muscular exertions place high loads
on the muscles, tendons, joints, and discs,
and so are associated with most
musculoskeletal disorders.
 Increased muscular exertion results in the
increase of muscles fatigue.
 With increased muscle fatigue, time needed
to recover increases. If recovery time is
limited, soft tissue injury is more likely to
occur.

 Repetitive Motion Injuries (RMI, also known
as RSI, CTD, CTS) are a class of injuries and
illnesses that result from weeks, months, or
years of overuse of human joints.
 Connective tissues can become sore and
sometimes unusable from repeated exposure
to micro-trauma.
 Because of the slow onset of symptoms,
people sometimes ignore the condition until
the symptoms become chronic and
permanent injury occurs.

 Awkward postures refer to positions of the
body (limbs, joints, back) that deviate
significantly from the neutral position while
job tasks are being performed.
 For example, when a person's arm is hanging
straight down (perpendicular to the ground)
with the elbow close to the body, the
shoulder is said to be in a neutral position.

 When employees are performing overhead
work such as installing or repairing
equipment or grasping objects from a high
shelf, their shoulders are far from the
neutral position.

 "Static work" refers to the musculoskeletal
effort required to hold a certain
position, even a comfortable one.
 For example, when we sit and work at
computers, keeping our head and torso
upright requires either small or great
amounts of static effort depending upon the
body positions we choose.

 Contact stress results from occasional,
repeated, or continuous contact between
sensitive body tissue and a hard or sharp
object.
 Contact stress commonly affects the soft
tissue on the fingers, palms, forearms,
thighs, shins and feet.

 Lightingthat is not appropriate for work task
is a major factor in visual discomforts such as
eyestrain, burning or itchy eyes, headaches
and blurred or double vision.

 Vibration restricts the blood supply to the
hands and fingers, which, depending on the
vibration level and duration of exposure, can
contribute to an ergonomic injury.
 Signs and symptoms of vibration-induced
injury, such as Reynaud's phenomenon, start
with occasional numbness or loss of colour in
the fingertips.

 Noise is an often overlooked part of the
working environment.
 Office machines, phones, and coworkers'
conversations can be a distraction.

 Cold temperatures reduce the natural
elasticity of the body and reduce the
sensation of touch (tactile feedback).
 In order to get the same amount of tactile
feedback, an employee may exert more
force than is necessary.

There are 5 primary phases of 5S:
sorting, straightening, systematic
cleaning, standardizing, and sustaining.
Additionally, there are three other phases
sometimes included; safety, security, and
satisfaction.

 Eliminate all unnecessary tools, parts, and
instructions.
 Go through all tools, materials, and so forth
in the plant and work area.

 The place for each item should be clearly labeled
or demarcated.
 Items should be arranged in a manner that
promotes efficient work flow, with equipment used
most often being the most easily accessible.

 Clean the workspace and all equipment, and
keep it clean, tidy and organized.
 At the end of each shift, clean the work area
and be sure everything is restored to its
place.

 All work stations for a particular job should
be identical.
 All employees doing the same job should be
able to work in any station with the same
tools that are in the same location in every
station.

 Maintain focus on this new way and do not allow a
gradual decline back to the old ways.
 While thinking about the new way, also be thinking
about yet better ways.

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Occupational Safety Health (OSHA)

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