Transcript Ergonomy in work place

Ergonomy in work place
Ergonomy presentation
Farnoosh Khodakarami
Hengameh Vahabzadeh
Supervisor:Mr.Ghayoor
Fall 2006
Ergonomy in work place
Ergonomy:
 Derived from the Greek ergon (work) and nomos (laws)
to denote the science of work, ergonomics is a systemsoriented discipline which now extends across all aspects
of human activity.
 Ergonomists contribute to the design and evaluation of
tasks, jobs, products, environments and systems in order
to make them compatible with the needs, abilities and
limitations of people
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Domains of specialization within the discipline of
ergonomics:
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Physical ergonomics
:is concerned with human anatomical,
anthropometric, physiological and biomechanical characteristics as they
relate to physical activity.
relevant topics
:working postures, materials handling,
repetitive movements, work related musculoskeletal disorders, workplace
layout, safety and health.
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Cognitive ergonomics :is concerned with mental processes,
such as perception, memory, reasoning, and motor response, as they
affect interactions among humans and other elements of a system.
relevant topics :mental workload, decision-making, skilled
performance, human-computer interaction, human reliability, work stress
and training as these may relate to human-system design.
Organizational ergonomics
:is concerned with the
optimization of sociotechnical systems, including their
organizational structures, policies, and processes.
relevant topics
:communication, crew resource
management, work design, design of working times, teamwork,
participatory design, community ergonomics, cooperative work,
new work paradigms, virtual organizations, telework, and quality
management.
Work place layout
work space
:Physical design of a workspace includes working out
how much space needed, and positioning of furniture, tools, equipment
and any other items needed to perform the tasks, in respect of posture,
access, clearance, reach and vision of the user.
work space factors :
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What type of task will be carried out and what specific actions are to be
used to complete the task?
Will the potential users of the workspace (your user population) be seated
or standing?
What postures will the users have to adopt?
What are the relevant body dimensions of the users? These dimensions
can be found in anthropometric tables.
Do you need to design using minimum, average or maximum dimensions?
How far can the users reach, horizontally and vertically?
What are the visual aspects of the task?
Body dimensions
- Designing for the 'average‘
- Designing for adjustability
- Designing for extreme individuals
The workspace envelope :
A 'workspace envelope' is a 3-dimensional space within which you
carry out physical work activities when you are at a fixed location.
Visual workspace :
Frequently viewed items should be positioned within a comfortable
zone in front of worker.
This is normally within 15° above, or 30° below, the horizontal, and
15° to the left and right.
In the normal, relaxed position of the head, neck and eyes, the line of
sight is about 10 to 15° below the horizontal
Distance is also a factor in visual fatigue.
Visual displays are comfortably viewed from 500-750mm or more
Ergonomy in office work
Features of an office such as people, space, equipment, furniture and
the environment, must fit together well for workers to feel healthy and
comfortable and to be able to work efficiently and productively.
The Environment :
The environment, or surroundings, in which workers are working
includes temperature, ventilation, humidity, lighting, noise etc factors.
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Lighting :
- Most people like to be able to see daylight
- Natural light is thought to make people feel better
- Monitors need to be positioned so that there is no glare or reflection on the
screen.
- Most people like to be able to control the artificial lighting levels in their work
area.
Light Source :
The primary light source that man has relied on for thousands of years is
the sun.
The variation in light levels over the 24 hours of the day is
important for two reasons:
- our bodies have natural rhythms
- we appear to have a biological need for light
Artificial light :
two main types of lamps used to provide interior lighting :
- incandescent light (light bulbs)
- fluorescent tube
Light Levels :
different tasks need different minimum amounts of light to be performed at a
satisfactory level ( Ex. paperwork and screen work as screens emit their own light )
Direction of light
Glare
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Temperature and ventilation :
A suitable physical climate is needed to feel comfortable and be
efficient at work. The environment feels comfortable when you are barely
aware of the climatic conditions. It is only when the temperature
decreases or increases beyond your comfort limits that you become aware
of discomfort.
comfort zone:
20-22ºC in winter
20-24ºC
in summer
Noise :
Noise is any annoying, disturbing or unwanted sound.
Noise effects on people :
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irritate people;
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interfere with verbal communication;
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reduce working efficiency;
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disturb sleep;
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damage hearing.
The effects of noise:
Deafness
The main effect of noise is the development of deafness, especially when
you are exposed to high levels of continuous noise. This may result in
'noise-induced occupational deafness'.
Noise and performance:
Noise causes fatigue and loss of concentration and efficiency, resulting in a
decrease in work output and an increase in the number of mistakes made
The World Health Organisation (WHO) provides some guidance on acceptable
levels of noise in the community.
Why ergonomics is important in office?
Injuries like:
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WRULD: work related upper limb disorders
Recent studies suggest a condition called e-thrombosis, an
ailment where blood clots form as a result of sitting for a long
length of time, is growing among professionals with desk jobs
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Repetitive Strain Injuries (RSI).
Professionals who spend an extensive amount of time in front
of computers are at high risk for Repetitive Strain Injuries
(RSI). These musculoskeletal disorders, including carpal
tunnel syndrome, tendonitis, lower back pain and tension
headaches,
Posture at work
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Changing your posture throughout the day is positive because
when you change postures, the loads of sitting shift to different
parts of the body, allowing your body to recover from extended
static postures.
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For most people, it is quite a challenge to maintain good posture
while sitting in an office chair and working for long hours in front
of a computer
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a surprising number of people sit at the front of their office chair
and hunch forward in an attempt to get closer to their computer
screen
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leaning forward 30 degrees in an attempt to get closer to the
computer screen puts 3 to 4 times more strain on the back
Technique to avoid hunching while
sitting in an office chair
To avoid the natural tendency to hunch forward while sitting in
an office chair and working at a computer, Place a tennis
ball between the middle back and the office chair on each
side of the spine
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if one does get absorbed into work and starts to lean
forward the tennis ball will fall out, serving as a concrete
reminder to stop hunching forward and straining the back.
Because the mind senses the ball, it remains connected
with the body instead of being completely absorbed by
what is on the computer screen. Maintaining more
awareness of the body allows one to more easily maintain
better posture
posture
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Your arms and legs Make sure that your upper arms are vertical (or close to
it), and your forearms are horizontal (or close to it) so that there is
approximately a right angle at your elbows
your shoulders should be relaxed,
your elbows should just about be level with the desk surface or very slightly
above. If not, you should adjust your chair to get you to the height that allows
this.
Your head and neck Aim to keep your neck vertical and relaxed and your
head upright.
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Look straight ahead at the screen, or slightly down (never up - too much
muscle use!). Adjust the height of the screen if necessary.
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Adjust the distance of the screen so
that you can read the characters
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Keep your wrists straight, in line with
your forearms, and relaxed.
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The forearm and hand make up 5%
of an average body weight so
improper positioning can result in fatigue
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Posture at work
Saet
Height
seat
The seat should be able to adjust until your thighs are
parallel to theground.
At a fixed-height work surface, the chair should be
set at a height so the worker's elbows are level with
the height of the workstation
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Saet pan
The seat pan depth should be adjustable to provide a fistwidth to three-finger gap between the back of the calf and the
front edge of the seat pan.
The seat pan should have a waterfall (rounded) front edge
Sharp corners, even when they’re made of padding, increase
the pressure on the backs of the thighs. A rounded front edge
distributes the pressure over a larger area.
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Backrest
The backrest height should be adjustable so the lumbar support can be fitted to
the low back
The backrest should mirror the shape of your back to provide support. It
should be able to support the natural curve of the spine
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Armrests
Armrests should be adjustable. They should allow the user's arms to rest
comfortably and shoulders to be relaxed.
They should be rounded on the edges.
Optional: most armrests are spaced too widely apart for the user to use
them comfortably
Swivel
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Any conventional style or ergonomic office chair should easily
rotate so the user can reach different areas of his or her desk
without straining
Seat material.
The material on the seat and back of the ergonomic office chair
should have enough padding to be comfortable to sit on for
extended periods of time. Having a cloth fabric that breathes is
preferable to a harder surface.
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The chair should have at least 5 castors at the base to
ensure stability
Footrests
If the feet cannot be firmly planted on the floor, then a footrest is
required
Footrests are way to shift postures or provide support for the feet
if the chair cannot be lowered
A footrest should be height adjustable. Adjust the footrest until
the thighs are parallel to the floor +/- 1-3 inches
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Desks
Desks are usually a standard height of about
720mm. This is fine for most people but.
Particularly short or tall people may need an
adjustable-height desk
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You need enough desk space for your
paperwork, the computer (monitor, keyboard
and mouse) and any additional equipment
that you need to do your job.
The desk should not have any obstructions
underneath like drawers or supports, that
force you to sit in uncomfortable positions
Some desks are 'radial' - L-shaped with a
curve in the middle where you sit. These can
be quite comfortable for computer work as
you can have everything you need close at
hand in an arc around you.
Keyboard
 The keyboard should be positioned
directly in front of the monitor
 when the user's fingers are placed on
 the keyboard, the forearms should rest
parallel to the floor with the upper arms
hanging comfortably to the sides.
 The keyboard should not force the user's
wrists into flexion. Constant flexion of the
wrists will cause unnecessary muscle
tension, which will often result in fatigue
and injury
 Place your keyboard in front of you with
enough room to rest your hands when you
are not typing.
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Mouse
The mouse should be positioned at the same height as the
keyboard.
The user should be able to access the mouse with their arm at a
comfortable 90• angle to eliminate any strain on the shoulder.
. Bring the mouse as close to the keyboard as you can so that
you don't have to stretch to use it.
Monitors
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The top of the screen should be at or below eye level
15” monitors are the minimum recommended size, though 17”
monitors becoming increasingly common
The monitor should sit directly in front of the user
Adjust the distance of the screen so that you can read the
characters clearly
The viewing distance to the computer screen should be between
13” – 28” to minimize eyestrain. Lighting is also very
important. The monitor should be at a 90•angle to a window,
where the light is least likely to produce a glare
Visibility: Keep the computer screen clean by wiping it very lightly
when needed with a damp paper towel or monitor cleaning
solution.
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Phones (Headsets)
Users who frequently use the phone and computer simultaneously or are on
the phone for extended periods of time should consider a headset
. Headsets reduce the tendency to cradle the phone and allow the user to
work with both hands while conversing on the phone
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Breaks –
Proper break periods are commonly overlooked when close to a deadline
or in a period of intense work. Taking the recommended ergonomics
breaks will increase energy, productivity and comfort while decreasing
stress
Short Breaks every hour are recommended for workers to perform at peak
ability and prevent injuries
Short, frequent breaks are more beneficial than longer, more infrequent
ones.
Sitting for more than an hour without moving can put stress on the body
due to the static posture that you are forced to sustain
Active breaks are a short time-out from typing or tasks being performing
for an extended period of time. This is not a break from work, just a break
from the activityThe user can get up and stretch, stand up while on the
phone
Eye Breaks are one of the most important breaks for workers who spend
most of their day staring at a computer screen. Eyestrain is a major cause
of tension headaches
At least once an hour focus on an object that is at least 20 feet away.
These few moments each hour can spare workers days of discomfort
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Exercises
a good exercise would be to stretch
muscles that are opposing the ones that
you normally use. This will allow you to
achieve a balance within muscle groups.
Roll your head in circles, stretching more
toward each shoulder
Eyestrain tip: Blink often, and take
frequent rest pauses; close your eyes for
a minute, refocus by looking away from
your monitor at something in the distance,
and roll your eyes up and down, left to
right.
Thanks for your attention