Ergonomics aims to optimize human well-being and system performance through understanding interactions between humans and other elements. Poor ergonomic design can result in discomfort, fatigue, injuries and reduced productivity. Key ergonomic considerations include anthropometry, biomechanics, muscular work, and postures. Checklists and standardization help assess ergonomic issues to improve workplace and job design.

1. Ergo nomics
1

2. First description/ writing……….
2

3. • Every 15 seconds, a worker dies from a work-related
accident or disease.
• Every 15 seconds, 151 workers have a work-related accident.
3

4. What is Ergonomics
• Ergo – from the Greek word meaning work
Nomos – from Greek word meaning natural laws
4

5. Definition:
Ergonomics (or human factors) is the
1. scientific discipline
2. understanding interactions -humans and other elements of a
system,
3. Professional application of principles ( theories, data and
methods) to design to optimize human well being & overall
system performance.
5

6. Objective:
• To improve the fit between the physical demands of the
workplace and the employees
i.e, To achieve best mutual adjustment of man and his work for
improvement of human efficiency and well being
6

7. History of Ergonomics
o World Wars
o Aircraft, weapon design
o Cold War
o Nuclear power plants
o Today
o Industry, hospitals, offices,
product design
7

8. History of Ergonomics
o Industrial Revolution
o Steel industry (shovels)
o Henry Ford
o Assembly line design
o Frank and Lillian Gilbreth
o Micro-motion studies (i.e.
today’s surgical techniques)
8

9. 9
Ergonomics Today
• More than Matching the job, work tools, and workplace to the
worker, but in all activities of day to day life and in recreation
sports and sleep.

10. • In 1777 Bernardino Ramazinni wrote
– about work-related complaints in his book "De Morbis
Artificum "
• In 1857- ergonomics word coined
– Term ‘Ergonomics’ was first coined by Wojciech
Jastrzebowski
10

11. • Early 19th century- ergonomic approach
• Frederick W. Taylor was a pioneer
• World war II- Prompted interest in human-machine
interaction
• 1970 – first act in the world - The Occupational Safety and
Health Act of 1970 (U.S.)
Purpose to "assure so far as possible every working man and
woman a safe and healthful working conditions to preserve
human resources.“
11

12. • 1857 – corrective ergonomics
• 1990s –prospective ergonomics
12

13. Ergonomic pioneers - Alphonse Chapanis
• Psychological and Brain Sciences
at Johns Hopkins University in
Baltimore.
• He was a founding father of
ergonomics, the science of human
factors in engineering design.
• Improving the safety of aircraft cockpits,
• the design of the standard telephone
touchpad,
• teleconferencing, safety labels,
• colorblindness, night vision,
• digitized speech and
• human-computer interaction are just
some of the projects he pioneered in his
lifetime. 13

14. Ergonomic pioneers - John Karlin
• John Karlin, father of human factors engineering
• John E. Karlin, a researcher at Bell Labs, studied ways to make
the telephone easier to use. (Image from the NY Times, courtesy of Alcatel-
Lucent USA) 14

15. Ergonomic pioneers - Niels Diffrient
(6 -9- 1928 to 8 -6- 2013)
• American industrial designer - focused mainly on ergonomic seating,
• well known designs are the Freedom and Liberty chairs, manufactured
by Humanscale
Diffrient World Chair 2009,
Liberty Chair 2004,
Diffrient Task and Work Light
2002,
Freedom Chair 1999, 15

16. 16
Ergonomics- concerns of ergo
Employee Concerns
– Comfort
• No Fatigue
• No Injuries
– Job satisfaction
• Decreased boredom
• Decreased stress
• Reasonable workloads
Employer Concerns
– Worker’s comp costs
– Productivity
– Errors
– Products
– Profit

17. productivity and
quality ∞ design of
working conditions.
One direct
economical
measure of
productivity—the
costs of
absenteeism
through illness—is
affected by working
conditions.
Design good =
decrease sickness
absence = increased
productivity
Good workplace design
Less absenteeism
Increased productivity
Reverse is reverse
17

18. So, Poor Ergonomics…..
o Decreased efficiency
o Decreased productivity
o Errors
18

19. Results of Poor Ergonomic Design
o Discomfort and fatigue
o Injuries and accidents
19

20. Musculoskeletal Disorders
o Necks
o Backs
o Arm and hand
o Knee and foot
Results of Poor Ergonomic Design
20

21. What Are Ergonomic Improvements?
Definition: Changes made to improve the “fit”
between a job and the capabilities of the employees
performing it
21

22. When you think about how to improve a workstation,
remember this rule:
• If it feels right, it probably is right. If it feels
uncomfortable, there is probably something wrong with
the design, not the worker.
22

23. Engineering Improvements
• Engineering improvements include rearranging
modifying, redesigning, or replacing:
• Workstations,
• Equipment,
• Tools,
• Packaging
• Reduce or eliminate existing hazards
• Most effective strategy
• Best time is when new facilities, processes, or work
procedures are being planned
23

24. Administrative Improvements
• Reduce exposure to the hazard by controlling behaviors
through design of safety rules and safe work practices and
procedures
• Include changing work practices or the way work is
organized
• Require continual management and employee compliance
to ensure that the new practices and policies are effective
24

25. Administrative Improvement Options
1. Providing variety in jobs
2. Adjusting work schedules and work pace
3. Providing recovery time (i.e., muscle relaxation time)
4. Ensuring regular housekeeping and maintenance of work
spaces, tools, and equipment
5. Increase workforce & Reduce workload
6. Training in recognition of risk factors
25

26. Safety Gear or
Personal protective equipment
• Provides a barrier between the worker and the hazard source
• Reduces the duration, frequency, or intensity of exposure
• Includes gloves, knee and elbow pads, respirators, ear
plugs, safety goggles, , aprons, safety shoes, and hats
26

27. Examples of ergonomic improvements
1. Use good quality
tools
2. Wear anti vibration
gloves
3. Lubricate tool
regularly
1. Put shock absorber
in vehicle
2. Use well designed
seat in vehicle
27

28. Benefits of ergonomics
• Reduced fatigue and discomfort
• Helps to prevent injuries like MSDs
• Improved quality of life
• Improved comfort, morale and job satisfaction
• Improved quality of work
• Improved productivity and reduced workers’ compensation costs
and employee turnover
• Reduced sickness absenteeism
28

29. Role of the health and safety
representative
• Ensure that ergonomics is used in
the workplace.
• Your efforts to ensure that
equipment and jobs are designed
or adapted to fit workers will help
to prevent a variety of health
problems caused by poor working
conditions.
29

30. Six-point strategy for winning ergonomic improvements in the
workplace
30

31. Six point strategy
1. Reach out to other workers
• Distribute copies of information factsheets or leaflets at
work.
• Listen to what others have to say about ergonomics-related
issues.
• Write down the names and work areas of people who are
experiencing symptoms which you suspect may be caused by
the non-application of ergonomic principles.
31

32. Six point strategy
2. Collect information to identify problem areas
3. Study the areas you suspect are a problem
• Walk through any problem areas and review the work tasks.
• Start thinking of solutions, such as raising tables, rotating
work, etc.
32

33. Six point strategy
4. Gather recommendations from:
• the workers who are affected;
• maintenance and repair workers;
• the union health and safety department (if one exists);
• other health and safety specialists.
33

34. Six point strategy
5. Push for necessary changes
• Worker support (plus documentation) will give you the
necessary encouragement for winning health and safety
contract language, grievances, or other agreements with
management.
6. Communicate with workers
• Two-way communication is important in building and
maintaining solidarity within the union.
34

35. Occupational health vs ergonomics
Occupational health
• Toxic stuff
• Etiology & management
ergonomics
• Workplace design
• Work design
• Productivity
35

36. Ergonomics- a multidisciplinary Science
36

37. ergonomics
Goals
Principles
Methods
Physical and
physiological
aspects
Psychological
aspects
Organizational
aspects of work
Work system
design
Design for
everyone
37

38. GOALS, PRINCIPLES, METHODS
GOALS, PRINCIPLES, METHODS
AIM
ANALYSIS OF ACTIVITIES, TASKS AND
WORK SYSTEMS
STANDARDISATIONS
CHECKLISTS
38

39. Aims of ergonomics
aims
productivity
quality
Safety and
health
efficiency Reliability
Job
satisfaction
personal
development
39

40. Analysis
• WORKERS - what they
bring to the job
• TOOLS - what they bring
to the worker
• TASKS - what the worker
must do
• ENVIRONMENT- the
conditions surrounding the
worker and the tool
40

41. 41
How Do I Start?
Identify problems
– Complaints of discomfort
– Symptom surveys
– Near misses
– Accidents
– Injuries
– Errors
– High turnover

42. Analysis of
the task
•data-based
analysis of the
activity
an accurate
determination
of prototype
put into
operation,
Then analysis of
performance of the users
and on dysfunctional
situations, such as accidents
or human error.
gathering of
information
on
final
corrections
increase the
reliability
Increase usability
of the completed
object.
• Eg. nuclear industry and the aeronautics industry serve as example:
operational feedback involves reporting every incident that occurs. In this
way, the design loop comes full circle. 42

43. Standardization in ergonomics
• 1970
• International organization for standardization
• Recent concept
43

44. Standardization in ergonomics-
principles
• Tasks within performance range
• to prevent injury
• tasks and working conditions will not lead to
impairments
44

45. standardisation….
• Standardisation committee
• iSO-CEN collobaration (to avoid duplication of
standards)
• Technical committee – sub committees
• Preparation of ergonomic standards-voting of
prepared draft
45

46. • standards on methods of anthropometric measurements,
• body dimensions,
• safety distances and access dimensions,
• the evaluation of working postures and
• the design of workplaces in relation to machinery,
• recommended limits of physical strength and problems of manual
handling.
Fields of ergonomic standardization
46

47. Checklist
• assessment
• Job Components Inventory
• ergonomic workplace analysis
• the checklists adopt one of two approaches,
• (1) the job-oriented approach
• (2) the worker-oriented approach
47

48. Checklist- to assess ergonomic
issues/considerations
• Organization, worker and the task
• Mechanistic aspect
– Job Specialization
– Skill Requirement
• Biological aspect
• General Physical Activity
• Manual Materials Handling (MMH)
• Workplace/Workspace Design
• Work Posture
• Work Environment
• NOISE
• CLIMATE
• LIGHTING
• DUST, SMOKE, TOXICANTS
• RADIATION
• VIBRATION
• Work Time Schedule
• Perceptual/motor aspect
• Displays
• Controls
• Technical aspect
• Machinery
• Small Tools/Implements
• Work Safety
• Psychosocial aspect
• Job Autonomy
• Job Feedback (Intrinsic and Extrinsic)
• Task Variety/Clarity
• Task Identity/Significance
• Mental Overload/Underload
• Training and Promotion
• Organizational Commitment
48

49. PHYSICAL AND PHYSIOLOGICAL ASPECTS
• ANTHROPOMETRY
• MUSCULAR WORK
• POSTURES AT WORK
• BIOMECHANICS
• GENERAL FATIGUE - FATIGUE AND RECOVERY
49

50. Anthropometry- measurement of people
• Physical characters of the body - defined, standardized and
referred to a unit of measurement
• For fitting
– equipment and work space to humans
– tailoring clothes to the right size.
• Equipment and work space require linear measures of
limbs and body,
• tailoring sizes are based mainly on arcs, girths and flexible
tape lengths.
• Both systems may be combined according to need.
50

51. Why Does it Matter?
o Average size is not good enough
o Need to consider reaches and clearances
51

52. Who Should We Match?
o Central 90 percent
o Disregard extreme body sizes
o Try to fit males/females from 20-65 yrs
52

53. The Golden Rule?
Design so the small woman can
reach, and the large man can
fit.
53

54. What Rule to Use Here?
Design so the small woman can
reach, and the large man can
fit.
54

55. What Rule to Use Here?
Design so the small woman can reach, and the large
man can fit.
55

56. Accommodating Reach
• How low can we
place materials
these workers
have to reach?
• How high can a
shelf be placed
holding work
materials?
Golden Rule: Place objects between knee and
shoulder height.
56

57. Measuring instruments-
anthropometers
57

58. Measurements of interest
• 1.1 Forward reach (to hand grip with subject standing upright against a wall)
• 1.2 Stature (vertical distance from floor to head vertex)
• 1.3 Eye height (from floor to inner eye corner)
• 1.4 Shoulder height (from floor to acromion)
• 1.5 Elbow height (from floor to radial depression of elbow)
• 1.6 Crotch height (from floor to pubic bone)
• 1.7 Finger tip height (from floor to grip axis of fist)
• 1.8 Shoulder breadth (biacromial diameter)
• 1.9 Hip breadth, standing (the maximum distance across hips)
• 2.1 Sitting height (from seat to head vertex)
• 2.2 Eye height, sitting (from seat to inner corner of the eye)
• 2.3 Shoulder height, sitting (from seat to acromion)
• 2.4 Elbow height, sitting (from seat to lowest point of bent elbow)
• 2.5 Knee height (from foot-rest to the upper surface of thigh)
• 2.6 Lower leg length (height of sitting surface)
• 2.7 Forearm-hand length (from back of bent elbow to grip axis)
• 3/19/2014 Anthropometry
58

59. Measurements of interest
• 2.8 Body depth, sitting (seat depth)
• 2.9 Buttock-knee length (from knee-cap to rearmost point of buttock)
• 2.10 Elbow to elbow breadth (distance between lateral surface of the elbows)
• 2.11 Hip breadth, sitting (seat breadth)
• 3.1 Index finger breadth, proximal (at the joint between medial and proximal phalanges)
• 3.2 Index finger breadth, distal (at the joint between distal and medial phalanges)
• 3.3 Index finger length
• 3.4 Hand length (from tip of middle finger to styloid)
• 3.5 Hand breadth (at metacarpals)
• 3.6 Wrist circumference
• 4.1 Foot breadth
• 4.2 Foot length
• 5.1 Heat circumference (at glabella)
• 5.2 Sagittal arc (from glabella to inion)
• 5.3 Head length (from glabella to opisthocranion)
• 5.4 Head breadth (maximum above the ear)
• 5.5 Bitragion arc (over the head between the ears)
• 6.1 Waist circumference (at the umbilicus)
• 6.2 Tibial height (from the floor to the highest point on the antero-medial margin of the glenoid of
the tibia)
59

60. Muscular work
• All occupational activities involve varying degrees of
muscular work.
• Ergonomically acceptable Workload in
Static, Dynamic, Manual Materials
Handling, Repetitive Work to be determined
, standardized and adopted.
• Prevent Muscular Overload
60

61. four groups:
dynamic -forestry,
agriculture and the
construction industry
Materials
handling -
nursing, transportation and
warehousing,
static- office work, the
electronics industry and in
repair and maintenance tasks.
Repetitivework - food
and wood-processing
industries
• It is important to note that manual materials handling
and repetitive work are basically either dynamic or static muscular
work, or a combination of these two. 61

62. • Repetition work can be
dynamic & can cause
repetition injuries
• fatigue will ensue, working
capacity is reduced, and
recovery slows down.
• Peak loads or prolonged
overload may result in
organ damage
62

63. Postures at Work
• Posture - the mutual organization of the trunk,
head and extremities
63

64. Posture and Movements
Posture and movements are influenced by
• The load- shape, stability, size, slipperiness
• Organization and environment- work force, overtime
• Personal factors- skills, clothing, illnesses
64

65. • A posture is
– source of musculoskeletal
load
– related to balance and
stability
– basis of skilled movements
and visual observation
– source of information on
the events taking place at
work
From a safety and health
point
• source of musculoskeletal
illnesses
• low back diseases
• Musculoskeletal problems
related to repetitive work
postures.
65

66. Low back pain
• Low back pain (LBP) is a generic term for various low
back diseases
– posture
– physically heavy work
possible mechanisms
• Forward bending & twisted posture - ↑ load on the
spine & ligaments
• Jerks and slipping, increase the loads on the back by a
large factor.
66

67. Recording and Measuring Working
Postures
• Self-reporting questionnaires and diaries
• Observation of postures
• Computer-aided postural analyses
• Video is usually an integral part of the recording and analysis process. The US
National Institute for Occupational Safety and
• Health (NIOSH) has presented guidelines for using video methods in hazard
analysis (NIOSH 1990). 67

68. 68

69. • Postural supports in the workplace and on
machinery, such as handles, supporting pads
for kneeling, and seating aids,
• useful in alleviating postural loads and pain.
69

70. Safety and Health Regulations
concerning Postural Elements
• The International Labour Organization published a Recommendation in
1967 on
– maximum loads to be handled.
– The Recommendation is now outdated
– served an important purpose in focusing attention on problems in manual
material handling.
• The NIOSH lifting guidelines (NIOSH 1981), as such, are not regulations
either, but they have attained that status. The guidelines derive
– weight limits for loads using the location of the load—a postural element—as
a basis.
• International Organization for Standardization
• the European Community, ergonomics standards and directives contain
matter relating to postural elements (CEN 1990 and 1991).
70

71. 71

72. Bio-mechanics
• Biomechanics is a discipline that approaches the
study of the body as though it were solely a
mechanical system
72

73. equivalents
• bones : levers, structural members
• flesh: volumes and masses
• joints: bearing surfaces and articulations
• joint linings: lubricants
• muscles: motors, springs
• nerves: feedback control mechanisms
• organs: power supplies
• tendons: ropes
• tissue: springs
• body cavities : balloons.
73

74. • The main aim of biomechanics is to study the way the
body produces force and generates movement.
• The discipline relies primarily on anatomy, mathematics
and physics;
• related disciplines are
– anthropometry (the study of human body measurements),
– work physiology and
– kinesiology (the study of the principles of mechanics and
anatomy in relation to human movement).
74

75. principles
• Muscles come in pairs.
• Muscles contract most
efficiently when the
muscle pair is in relaxed
balance
75

76. • Applications
– In designing tools and
equipment for optimum
use and recommends
healthy and safe
posture, movement &
force application
direction-repetition for
optimum results by
experiments and
research
• The optimum diameter of
tool handles- 40mm
• The use of cutting-pliers
• Seated posture
• Screw-driving
• Manual Material Handling
76

77. Manual Material Handling
• manual handling includes lifting, lowering, pushing,
pulling, carrying, moving, holding and restraining,
and encompasses a large part of the activities of
working life.
77

78. • How much can be handled without damage to the
body - biomechanical criterion.
• How much can be handled without overexerting the
lungs - physiological criterion.
• How much do people feel able to handle comfortably?
- psychophysical criterion.
78

79. 79
Recommendations Handling weight
Reduce lifting
– Lifting equipment
– Job redesign

80. 80
Manual Materials Handling
o Golden rule
– Eliminate lifts
o When you can’t
– Keep it off the floor
– Reduce lifts
• Conveyors, dollies
• Adjust work flow

81. 81
Making a Difference
If they have to lift, teach them
how!
– High risk groups first
– Then campus-wide

82. How Should You Lift?
Stoop
Squat
Semi-squat
82

83. Stoop
o Can get close to load
o Less effort and energy
than squatting
o Fast
….but it increases strain on
low back
83

84. Squat
Limits strain on low back
….but it is difficult to keep
load close
….requires increased effort
and energy
….and it is inefficient
84

85. Semi-Squat Lift
o Less work
o Preferred for
lifting heavy
objects on
occasional basis
85

86. Squat and Semi-Squat Lifts
o More protective of back
o Preferred by injured workers
86

87. 87
There are no “right” or “correct”
ways to sit, stand or lift....
However, there are more and
less demanding ways!

88. 88
Keep It Simple
o Staggered stance o Keep it close

89. 89
Keep It Simple
o Build a Bridge o Feet first

90. Ergonomics principles during heavy physical work
Stand close to objects and
feet slightly apartKeep back straight
Use both hands and
grip with whole hand
Place feet in walking position Take help of others 90

91. Threblig approach
• Therbligs are 18 kinds of elemental motions
• the study of motion economy in the workplace.
• analyzed by recording each of the therblig units for a process,
• results used for optimization of manual labor by eliminating
unneeded movements.
• The word therblig was the creation of Frank Bunker
Gilbreth and Lillian Moller Gilbreth, American industrial
psychologists who invented the field of time & motion study. It is a
reversal of the name Gilbreth, with 'th' transposed
91

92. 92

93. Recommendations for heavy work
1. Reduce the weight of the load
2. Make the load easier to handle
3. Use storage techniques to make handling materials easier
4. Minimize the distance a load must be carried
5. Minimize the number of lifts required
6. Minimize twisting of the body
93

94. Recommended Weight Limits
• impossible to state a weight that will be “safe”
in all circumstances
• National Institute for Occupational Safety and
Health (NIOSH) in the United States has
adopted 23 kg as a load limit in 1991
94

95. Lifting
• The maximum weights recommended by the International
Labour Organization are:
• Men: occasionally 55 kg.,
repeatedly 35 kg.
• Women: occasionally 30 kg.,
repeatedly 20 kg.
Under continuous research
• Do not lift anything if you have backache.
• Once the pain has gone, start lifting with caution and
gradually practise.
95

96. Lighting
• daylight - provide an outside
view.
• Light colours for walls and
ceilings when more light is
needed.
• Light up corridors, staircases,
ramps and other areas
• indirect lighting
• Sit at right angles to windows
and at least 3 feet away
• Adjust desk lamp or task light
to avoid reflections
• Light up the work area evenly
to minimize changes in
brightness.
• Provide local lights for
precision or inspection work.
• Full-Spectrum fluorescent
mimic natural light but cost
more.
• Age - 20 vs 65 yrs
96

97. 97

98. Lighting
• Computer screens /other workstations may need to be repositioned to eliminate glare
• Anti-glare screens
• Adjust drapes or blinds to reduce glare.
• limit reflected glare, by painting medium or dark color to wall and not have reflective
finish.
• Monitors in relation to glare
• monitor’s brightness should match the room-
• Adjust the brightness control close to the mid-range
• set a higher contrast, the better.
• Do this more than once a day if the light changes in the room.
98

99. Temperature
• Elevated temperatures
and humidity can be
harmful.
• Low temperatures can
reduce finger flexibility
and accuracy
• affected by several factors
including type of work,
clothing and heat
sources, and amount of
airflow.
99

100. Premises
• Protect workers from
excessive heat.
• Isolate or insulate sources
of heat or cold.
• Install effective local
exhaust systems that allow
efficient and safe work.
• Improve and maintain
ventilation systems to
ensure good workplace air
quality.
• Provide enough fire
extinguishers within easy
reach and be sure that
workers know how to use
them.
• Recycle wastes to make
better use of resources and
protect the environment.
100

101. Noise
• Excessive noise levels above 90
decibels (dBA) and noise peaks
above 100 decibels 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.
101

102. Manage noise & Hazardous substances
• Isolate or cover noisy
machines or parts of
machines.
• Choose electric hand-
held equipment that is
well insulated against
electric shock and heat.
• Ensure safe wiring
connections for
equipment and lights.
• Label and store properly
containers of hazardous
chemicals to
communicate warnings
and to ensure safe
handling.
102

103. 103

104. watch
104

105. fatigue
• Neurophysiological
interpretation of
fatigue
• Inhibition and
activation
• Clinical fatigue
• Preventive Measures
105

106. Physical/mental
capability,
preexisting
conditions, etc
Noise, temperature,
humidity etc
•Heavy, Frequent, or
Awkward Lifting
•Pushing, Pulling or
Carrying Loads
•Working in
Awkward Postures
•Hand Intensive
Work
•Repetitive motions
•Forceful exertions
•Vibration
106

107. 107

108. Preventive Measures
• attention to general working conditions and the
physical environment at the workplace & ergonomic
improvements
– correct arrangement of hours of work,
– provision of adequate rest periods
– suitable canteens , rest rooms;
– adequate paid holidays
– ensuring that seats, tables and work benches are of suitable
dimensions
– correctly organized. Work flow
– noise control,
– air-conditioning, heating, ventilation and lighting
108

109. Preventive Measures
• Monotony and tension may also be alleviated by
– a controlled use of color and decoration in the
surroundings,
– intervals of music and
– sometimes breaks for physical exercises for sedentary
workers.
• Training of workers and in particular of supervisory
and management staff also play an important part.
109

110. PSYCHOLOGICAL ASPECTS
• MENTAL WORKLOAD
• VIGILANCE
• MENTAL FATIGUE
110

111. Mental Workload
• Time pressure
• Qualification and training
• Abstract thinking
• Emotion management
• Coping with daily stress
• Stress management skills-
commmunication skills
• Self motivation and motivational
skills
• Teaching ability-learning ability
• Physical health
• Management skills
• Appropriate task assignment
Findings in this area led to the technique of
health and personality promoting task design
(Hacker 1986).
111

112. vigilance
• The concept of vigilance refers to a human
observer’s state of alertness in tasks that demand
efficient registration and processing of signals
112

113. vigilance
• Low overall vigilance in all aspects from
beginning.
• Gradual decline over a period
• Studied by percent of faulty products
113

114. Low vigilance - causes
• sleep deprivation, which is “de-arousing”.
• depressant drugs like benzodiazepines or alcohol and stimulant
drugs like amphetamine, caffeine or nicotine.
• With respect to age, vigilance performance increases during
childhood and tends to decline beyond the age of sixty.
• Physical and mental diseases
• Lack of training/ education/ motivation/ supervision
114

115. Improving vigilance
• frequent short breaks,
• job rotation,
• job enlargement or job enrichment.
• Introduction of variety can be as simple as having the
inspector himself or herself getting the material to be
inspected from a box or other location
115

116. Mental fatigue
• Symptoms of mental fatigue
• perception: reduced eye movements
• information processing: extension of decision time, action
slips, decision uncertainty, blockings, “risky strategies” in action
sequences, disturbances in sensorimotor coordination of
movements
• memory functions: prolongation of information in ultrashort-
term storages , disturbances in the rehearsal processes in short-
term memory, delay in information transmission in long-term
memory and in memory searching processes.
116

117. Prevention of Mental Fatigue
• 1. Changes in the structure of tasks.
– Technology assistance (monitoring by robots- x-ray/ by alarm
on malfunction or faulty product identification)
• Designing
• Information processing
• Human-centered technologies to reduce the mental effort
– Well-balanced coordination of different levels of regulations
– Training workers in goal-directed action
• 2. Introduction of systems of short-term breaks during
work.
• 3. Sufficient relaxation and sleep
117

118. ORGANISATIONAL ASPECTS OF WORK
• WORK ORGANISATION
• SLEEP DEPRIVATION
118

119. Work Organization
• Problems with organization are primarily
attributable to continuous attempts at
implementing the latest technology in
unsuitable organizational structures
• qualifications of employees
• Use of Technology
– Insufficient technology
– Unsuitable technology.
– Excessively complex technology
• training is too frequently regarded as a cost
factor to be controlled and minimized, rather
than as a strategic investment
• From the Task to the Design of Socio-
Technical Systems
• The Concept of Complete Task
119

120. Work Organization
• Design of Production
Systems-computer/ human
centered
• Use of Technology
– Insufficient technology
– Unsuitable technology.
– Excessively complex
technology
• From the Task to the Design
of Socio-Technical Systems
• The Concept of Complete
Task
• Participatory – democratic Vs
non-participatory
• Vertical – doing by order and
non-participatory and non-
expressive
• Participatory in decision
making and ergonomically
compatible- horizontal
• Organic(human centered) vs
non-organic(technology
oriented-robotic)
120

121. • Though participatory is fruitful further research is still on……
121

122. Sleep Deprivation
122

123. 123

124. • Effects
• Declining performance
• Solution
• Increasing flexibility in work schedules in combination with
better job design
• general conclusion is that we should minimize night sleep
deprivation by selecting appropriate work schedules
• facilitate recovery by encouraging individually suitable sleeps,
replacement sleeps and a sound night-time sleep in the early
periods after sleep deprivation in good environment of long rest
period to allow recovery.
124

125. WORK SYSTEM DESIGN
• WORKSTATIONS
• TOOLS
• CONTROLS INDICATORS, PANELS
• INFORMATION PROCESSING AND DESIGN
125

126. Workstation-A Workstation Design Process
collection
of user-
specified
demands
prioritizing
of
demands
transfer of
demands into (a)
technical
specifications and
(b) specifications in
user terms
iterative devel
opment of the
workstation’s
physical
layout
physical
implement
ation
trial period
of
production
full
production
evaluation and
identification
of rest
problems.
126

127. The collection of the user-specified demands should
meet a number of criteria
• Openness.
• Non-discrimination.
• Development through dialogue.
• Versatility. The process of collection of user-specified
demands should be reasonably economical and not
require the involvement of specialist consultants or
extensive time demands on the part of the
participants.
127

128. Ergonomics principles at Workstation
•Consider ergonomic factors like head height, shoulder
height, arm reach, elbow height, hand height, leg length, and
hand and body size while designing a workstation
25 cm
50 cm
100 cm
160 cm
128

129. Musculoskeletal load variables
• muscular force demand
• working posture demand
• time demand.
129

130. The cube model
130

131. 131
Where Should one Look?
Offices and Telecommuters

132. 132
Where Should one Look?
Laboratories

133. 133
Where Should one Look?
Hospitals

134. 134
Where Should one Look?
Facilities

135. 135
Where Should one Look?
Shops

136. 136
Where Should one Look?
Grounds

137. 137
Where Should I Look?
o Housekeeping
o Dining
o Housing
o Student stores

138. 138
What Can Ergonomics Do?
• ↓ discomfort
• ↓ accidents and injuries
• ↑ accuracy
• ↑ efficiency
• ↑ satisfaction
• ↑ job retention

139. 139
What Should I Look For?
Awkward postures
Repetition
Force

140. A Workstation Design Example:
Manual Welding
140

141. 141

142. • On the basis of the results of the first stages of the design process, a
welding workplace (figure 3) was implemented. Assets of this
workplace include:
• Work in the optimized zone is facilitated using a computerized
handling device for welding objects. There is an overhead hoist for
transportation purposes. As an alternative, a balanced lifting device
is supplied for easy object handling.
• The welding gun and grinding machine are suspended, thus reducing
force demands. They can be positioned anywhere around the
welding object. A welding chair is supplied.
• All media come from above, which means that there are no cables on
the floor.
142

143. • The workstation has lighting at three levels: general, workplace
and process. The workplace lighting comes from ramps above the
wall elements. The process lighting is integrated in the welding
smoke ventilation arm.
• The workstation has ventilation at three levels: general
displacement ventilation, workplace ventilation using a movable
arm, and integrated ventilation in the MIG welding gun. The
workplace ventilation is controlled from the welding gun.
• There are noise-absorbing wall elements on three sides of the
workplace.
• A transparent welding curtain covers the fourth wall. This makes it
possible for the welder to keep informed of what happens in the
workshop environment.
143

144. Additional variables
• precautions to reduce risks for accidents
• specific environmental factors such as noise,
lighting and ventilation
• exposure to climatic factors
• exposure to vibration (from hand-held tools
or whole body)
• ease of meeting productivity and quality
demands.
144

145. tools
• Nature of grip
• Power
• Pinch
• pencil
145

146. • Grip thickness
• Grip strength and hand span
146

147. • Handles
• Shape
• Grip surface and texture
• Length
• Weight and balance
• Significance of gloves
• Handedness
• Significance of gender
• Special consideration
147

148. • Pliers and cross lever tools
• Knives
• Hammers
• Screwdrivers and scraping tools
• Saws and power tools
148

149. Ergonomic principles while using hand
tools
149

150. Controls indicators panels
• Sitting
• Standing
• Foot operated controls
• Selection of controls
• Preventing accidental operations
• Data entry devices
• Displays
• Labels
• warnings
150

151. sitting
151

152. 152

153. 153

154. Ergonomic guidelines for sitting work
154

155. Ergonomics principles during sitting position
Bending forward
No wrist support
No foot rest
Back straight and
supported
Wrist supported and
straight
Foot supported
155

156. chair
1. Provides lumbar support.
2. Height can be adjusted.
3. Width is appropriate for the individual using
the chair.
4. Backrest is adjustable.
5. Seat depth – well-fitted or adjustable.
6. Adjustable or removable armrests.
7. Five-prong base.
8. Breathable fabric.
9. Well-fitted – small, medium or large chair
156

157. 157

158. Computer ergonomics
158

159. • Use detachable mouse
• Use tilt
• Use keyboard
• Very frequent breaks in
laptop use is advised
159

160. 160

161. 161

162. 162

163. Computer & Desk Stretches
(Approximately four minutes)
163

164. Ergonomics principles during
standing position
164

165. • A chair, footrest, a mat
to stand on, and an
adjustable work
surface are essential
components for a
standing workstation.
165

166. 166

167. Foot operated controls
• Sitting posture
• Locate pedals underneath the body, slightly in front,
– so that they can be operated with the leg in a comfortable position. The total horizontal
displacement of a reciprocating pedal should normally not exceed about 0.15 m. For rotating
pedals, the radius should also be about 0.15 m. The linear displacement of a switch-type pedal
may be minimal and should not exceed about 0.15 m.
• Pedals should be so designed that the direction of travel and the foot force are
approximately in the line extending from the hip through the ankle joint of the
operator.
• Pedals that are operated by flexion and extension of the foot in the ankle joint
should be so arranged that in the normal position the angle between the lower leg
and the foot is approximately 90°; during operation, that angle may be increased to
about 120°.
• Foot-operated controls that simply provide signals to the machinery should
normally have two discrete positions, such as ON or OFF. Note, however, that tactile
distinction between the two positions may be difficult with the foot.
167

168. Selection of Controls
• Selection among different sorts of controls must be made
according to the following needs or conditions
– Operation by hand or foot
– Amounts of energies and forces transmitted
– Applying “continuous” inputs, such as steering an automobile
– Performing “discrete actions,” for example, (a) activating or
shutting down equipment, (b) selecting one of several distinct
adjustments, such as switching from one TV or radio channel
to another, or (c) carrying out data entry, as with a keyboard.
168

169. controls preferred
169

170. 170

171. Some examples of "detent" and
"continuous" controls
171

172. Ergonomics principles during using controls
Poor control position
Good control position – lowered palm buttons can
allow arms to be lower than shoulders and provide safety
172

173. 173

174. Preventing Accidental Operation
• Locate and orient the control so that the operator is unlikely to strike it or move it
accidentally in the normal sequence of control operations.
• Recess, shield or surround the control by physical barriers.
• Cover the control or guard it by providing a pin, a lock or other means that must be
removed or broken before the control can be operated.
• Provide extra resistance (by viscous or coulomb friction, by spring-loading or by
inertia) so that an unusual effort is required for actuation.
• Provide a “delaying” means so that the control must pass through a critical
position with an unusual movement (such as in the gear shift mechanism of an
automobile).
• Provide interlocking between controls so that prior operation of a related control is
required before the critical control can be activated.
174

175. Data entry devices
• All controls can be used
• One key one character
• Rows-columns
• Separate numeric tabs
• Pushbutton types
• Keyboard keys
• Angulation, gaps, resurface
175

176. Displays
• Displays provide information about the status of
equipment.
• Displays may apply
– to the operator’s visual sense
(lights, scales, counters, cathode-ray tubes, flat panel
electronics, etc.),
– to the auditory sense (bells, horns, recorded voice
messages, electronically generated sounds, etc.) or
– to the sense of touch (shaped controls, Braille, etc.).
• Labels, written instructions, warnings or symbols
(“icons”) may be considered special kinds of displays.
176

177. • The four “cardinal rules” for displays are:
– Display only that information which is essential for adequate
job performance.
– Display information only as accurately as is required for the
operator’s decisions and actions.
– Present information in the most direct, simple, understandable
and usable form.
– Present information in such a way that failure or malfunction
of the display itself will be immediately obvious.
177

178. • The selection of either an auditory or visual display depends on
the prevailing conditions and purposes. The objective of the
display may be to provide:
• historical information about the past state of the system, such as
the course run by a ship
• status information about the current state of the system, such as
the text already input into a word processor or the current
position of an airplane
• predictive information, such as on the future position of a
ship, given certain steering settings
• instructions or commands telling the operator what to do, and
possibly how to do it.
178

179. • A visual display –
– is most appropriate if the environment is noisy, the
operator stays in place, the message is long and
complex, and especially if it deals with the spatial
location of an object.
• An auditory display
– is appropriate if the workplace must be kept dark, the
operator moves around, and the message is short and
simple, requires immediate attention, and deals with
events and time.
179

180. 180

181. ypes
181

182. color
182

183. 183

184. warnings
• Warnings
• Ideally, all devices should be safe to use.
• It is preferable to have an “active” warning,
• sensor that notices inappropriate
use, combined with
• an alerting device that warns the human of
an impending danger.
184

185. • Use warning signs that
workers understand
easily and correctly.
185

186. Passive warnings
• label attached to the product
• instructions for safe use in the user manual.
• passive warnings rely completely on the human user to recognize an existing or
potential dangerous situation, to remember the warning, and to behave
prudently.
• Labels and signs for passive warnings
– must be carefully designed by following the most recent government laws and regulations,
national and international standards, and
– the best applicable human engineering information.
– text, graphics, and pictures—often graphics with redundant text.
– Graphics, particularly pictures and pictograms, can be used by persons with different
cultural and language backgrounds, if these depictions are selected carefully.
– users with different ages, experiences, and ethnic and educational backgrounds, may have
rather different perceptions of dangers and warnings.
Therefore, design of a safe product is much preferable to applying warnings to an inferior
product.
186

187. Ergonomic design is the application of this body
of knowledge to the design of the workplace
(work tasks, equipment, environment) for
safe and efficient use by workers.
Good ergonomic design makes the most
efficient use of worker capabilities while
ensuring that job demands do not exceed
those capabilities.
187

188. Information processing and design
• Sensory input – clear understandable
• Mind-processing- education / training/
vigil/warning
• Output – motor capabilities
• Feasible Design
188

189. 189

190. DESIGN FOR EVERYONE
• FOR SPECIFIC GROUPS
• CULTURAL DIFFERENCE
• ELDERLY WORKERS
• WORKERS WITH SPECIAL NEEDS
190

191. Designing for specific groups
• By using
– The literature of research results.
– Direct observation of the disabled person at work
and description of his or her particular work
difficulties.
– The interview.
– Questionnaires.
– Physical measurements.
191

192. 192

193. Cultural differences
• Definitely taken into account in ergonomic
design
• Sikhs with turban
• Definition of culture is way of life- complex to
explain
193

194. ageing
• Slow process in industry
• Addressed by
– reduction in extreme stresses, using all possible
strategies for work organization, and
– continuous efforts to increase skills,
– efficient and less expensive when they are taken
over the long term and are carefully thought out
in advance.
194

195. Workers with special needs
• modification of the task
• modification of a tool
• design of new tools or new machines
195

196. assessment
• 1. Personnel
– Absence. Will the disabled worker have a satisfactory attendance record?
– Is it likely that extra costs may be incurred for special task instruction?
– Are personnel changes called for? Their costs must be considered also.
– Can accident compensation rates be expected to increase?
• 2. Safety
– Will the job being considered for the disabled worker involve safety regulations?
– Will special safety regulations be involved?
– Is the work characterized by a considerable frequency of accidents or near accidents?
• 3. Medical
– As regards the worker whose disability is being examined with a view to his or her re-entry
into the workplace, the nature and seriousness of the incapacity must be assessed.
– The extent of the disabled worker’s absence must also be taken into account.
– What is the character and frequency of the worker’s “minor” symptoms, and how are they to
be dealt with? Can the future development of related “minor” illnesses capable of hampering
the worker’s efficiency be foreseen?
196

197. • Consider the easy
access to and use of
equipment and facilities
for disabled
workers, taking account
of their particular
needs.
• Make the tasks assigned
to pregnant women
comfortable and
individually adjustable
197

198. Global fatalities - ILO
• Health and safety at work: > 2 million people
die each year from work-related diseases.
• > 3 lakh people die each year from
occupational accidents.
• > 150 million non-fatal work-related diseases
per year.
• > 300 million non –fatal occupational
accidents per year.
198

199. Occupational risk factors such as the
following, contribute markedly to
global illness and injury:
• 37% of back pain
• 16% of hearing loss
• 13% of Chronic Obstructive
Pulmonary Disease (COPD)
• 11% of asthma
• 9% of Trachea, bronchus lung cancer
• 8% of injuries
• 2% of leukemia
199

200. India
• As per Director General of Factory Advisory Services & Labour
Institutes [DGFASLI] there are 300,000 registered industrial
factories and more than 36500 hazardous factories employing
2046092.
• Approximately 10 million persons were employed in various
factories.
• The current burden of accumulated occupational diseases in
India is estimated to be at around 18 million cases.
200

201. Indian Statistics
• Rates of fatal injuries – >110 per 100,000 workers
• Rates of non-fatal injuries – >300 per 100,000 workers
• Cases of injury with lost workdays:
 Fatal case – >2000
 Non-fatal case – >6000
 Cases of temporary incapacity – >3000
(Source – Labour statistics database by ILO)
201

202. Work-related Injuries and Disorders
• Workrelatedmusculo-skeletaldisordersaremostcommon
• Alsoknownas:
– RepetitiveStrainorStressInjury(RSI)
– CumulativeTraumaDisorder(CTD)
– OveruseSyndrome
• Occupationaldisordersofthesoftissueslikemuscles,tendons,
ligaments,joints &nerves
• Usuallyoccurslowlyovertimedue torepetitiveinjuriestothesoft
tissuesandnervoussystem
• Symptoms of WMSD:
Discomfort, Pain, Numbness, Tingling, Burning, Swelling,
Tightness, loss of flexibility 202

203. • Repetition
• Forceful Exertion
• Direct Mechanical Pressure
• Static Posture
• Inadequate Recovery Time
• Awkward Posture
• Environmental Stressors
203

204. 204
What Causes These Injuries?
Risk
Factors
Repetition
Forceful
Exertion
Direct
Mechanical
Pressure
Static
Posture
Inadequate
Recovery
Time
Awkward
Posture
Environmen
tal Stressors

205. • MSDs occur when the physical capabilities of the worker
do not match the physical requirements of the job
 Prolonged exposure to ergonomic risk factors can cause
damage to a worker’s body and lead to MSDs
205

206. Injuries Common sites Cause
Bursitis knee, elbow,
shoulder
Kneeling, pressure at the
elbow, repetitive shoulder
movements
Carpal tunnel syndrome wrist Repetitive work with a bent
wrist. Use of vibrating tools.
Epicondylitis Elbow Repetitive work, often
strenuous
Ganglion Back of hand or
wrist
Repetitive hand movement
Osteo-arthritis Any joint Awkward liftting, pulling,
pushing
Tendonitis Any site Repetitive movements
Tenosynovitis Any site Repetitive movements, often
nonstrenuous
Tension neck or shoulder Neck or shoulders Sustained awkward postures
Trigger finger Fingers Repetitive movements.
Excessive gripping 206

207. Evaluation of the job
Does your job require you to:
• Repeatedly bend and twist your wrists?
• Repeatedly twist your arms?
• Repeatedly hold your elbows away from your body?
• Repeatedly use a pinch grip?
• Repeatedly reach or lift things above shoulder level?
• Repeatedly use a tool that vibrates?
(Analysis questionnaire)
207

208. • Repeatedly use your hand to apply force?
• Repeatedly twist or flex your back?
• Repeatedly lift objects from below knee level?
• Repeatedly work with your neck bent?
All of the above are “risky positions” that can lead to the
development of repetitive strain injuries.
208

209. Ergonomics - organisations
• Formed in 1946 in the UK, the oldest professional body for
human factors specialists and ergonomists is The Institute of
Ergonomics and Human Factors, formally known as The
Ergonomics Society.
209

210. National Ergonomics Month
• In 2003, the Human Factors and Ergonomics Society (HFES)
designated October of every year to be National Ergonomics
Month (NEM).
• The purpose of NEM is to focus on promoting human
factors/ergonomics to corporate executives, students, and
the general public by providing information and services to
the community
210

211. World Day for Safety and Health
at Work
• The ILO celebrates it on the 28 April to promote the
prevention of occupational accidents and diseases globally.
• It is an awareness-raising campaign intended to focus
international attention on emerging trends in the field of
occupational safety and health and on the magnitude of
work-related injuries, diseases and fatalities worldwide.
•
In 2014, the theme of the World Day for Safety and Health at
Work is:
safety and health in the use of chemicals at work
211

212. International Ergonomics Association
• Is a federation of ergonomics and human factors societies
from around the world.
• The mission of the IEA is to elaborate and advance
ergonomics science and practice, and to improve the quality
of life by expanding its scope of application and contribution
to society.
212

213. Ergonomic Checkpoints
• International Ergonomics Association (IEA)+ the International
Labour Office (ILO)
• 132 realistic and flexible solutions to ergonomic problems
applicable across a whole range of workplace situations like
Materials storage and handling, Hand tools , Machine
safety, Workstation design, Lighting, Premises , Control of
hazardous substances and agents, Welfare facilities and Work
organisation
213

214. Ergonomics in India
• In the early sixties,
• Industrial Physiology division of the Central Labour Institute,
Mumbai, under the Ministry of Labour, Govt. of India,
• evaluated the work loads of different occupations and Acceptable
Work Load for Indian industrial workers was defined.
• Anthropometry of the Indian population was also studied in detail.
214

215. • The first teaching
• Department of Physiology, University of Calcutta in 1971,
• post-graduate science course in Work Physiology and
Ergonomics.
215

216. • The National Institute of Occupational Health, Ahmedabad
was established in 1966 under the Ministry of Health and
Family Planning, Govt. of India,
• Occupational Physiology division - extensive research in
thermal stress and comfort, agricultural ergonomics, and
women workers.
216

217. • The All-India Institute of Hygiene and Public Health, Kolkata,
an institute aimed at developing health manpower ,
• Research in ergonomics, focus being on load carrying and
the occupational stress of pulling a hand-pulled rickshaw.
217

218. • Incorporated in curriculum at the Industrial Design Centre of
the Indian Institute of Technology Bombay (IITB), in the year
1979 at the post-graduate level,
• Later in Indian Institutes of Technology Delhi, Guwahati, and
Kanpur.
218

219. • Ergonomics has always been a part of Defence research
• The Defence Institute of Physiology and Allied Sciences
(DIPAS)
– including nutrition of soldiers,
– load carriage and distribution in infantry soldiers,
– thermal comfort.
• Research
– performance in extreme environments,
– development of a protective mechanism against noise induced
hearing loss and
– evaluation of thermal protective clothing.
219

220. • The earliest reports of
enterprise-level
ergonomics in India are
from the Hindusthan Lever
works and Tata Steel.
220

221. • The public-sector Bharat
Heavy Electricals Ltd.
(BHEL), Tiruchirapalli, - first in
Indian industry to introduce
in-house Ergonomics unit in
1983,
221

222. Organisations in India
Indian Society of Ergonomics
• 1983
• only professional body representing ergonomics / human factors
professionals in India.
• Affiliated to the International Ergonomics Association (IEA) and
nominates members to its committees.
• Members -wide variety of fields, including
physiology, psychology, occupational health, industrial safety, and
engineering, reflecting the multi-disciplinary nature of the subject.
222

223. Overview of the development of
ergonomics
Ergonomics research in India (past 50 yrs)
• physical work capacity, work stress of different occupation
• the diverse anthropometry of the people of this region
• load carrying – mainly in the unorganized sector
• improvement of working conditions in adverse
environments, including hot and humid environments
223

224. • certain aspects of agriculture (upon which most rural people
still depend) including high profile areas like tea cultivation
• low-cost improvements for some traditional and unorganized
sectors
• product design
• women at work; and recently,
• the electronics and information technology (IT) sectors.
224

225. BASIC ERGONOMIC PRINCIPLES
• work in neutral postures
• reduce excessive force
• keep everything in easy reach
• work at proper heights
• reduce excessive motions
• minimize fatigue and static load
• minimize pressure points
• provide clearance
• move, exercise, and stretch
• maintain a comfortable environment
225

226. Welfare facilities
Provide:
• Provide & maintain good changing, washing and sanitary facilities
to ensure good hygiene and tidiness.
• Drinking facilities and hygienic eating areas
• Rest facilities for recovery from fatigue.
• Easy access to first-aid equipment and primary healthcare
facilities at the workplace.
• Clearly mark areas requiring the use of personal protective
equipment.
• Ensure regular use of personal protective equipment by proper
instructions, adaptation trials and training. 226

227. 227

228. 228