By Dr M Muzamil, Aasstt Prof SKUAT, J & K

1. ERGONOMIC CONSIDERATIONS IN
DESIGNING AGRICULTURAL MACHINERY
Dr. M. Muzamil
Assistant Professor
College of Agricultural Engineering and Technology
SKUAST-K, Shalimar
email; muzamil4951@gmail.com
Agricultural Training
Institute, Ahmednagar

2. Types of Agricultural System
Parameters Industrial
system
Green revolution
Sytem
Resource poor agricultural
system
Location Industrialized
countries
Irrigated stable
rainfall, high potential
areas in Asia
Rainfed areas, Sub-Saharan
Africa
Farmers Highly capitalized
family farms
Small and large farmers Small and poor farm
households
Use of purchased
inputs
Very high High Low
Farming system Simple Simple Complex
Production stability Moderate risk Moderate risk High risk
Production level High Near the limit Low
Priority for
production
Regulate
production
Maintain production Raise production

3. HOW? WHY?

4. Why seats are placed in this way?

5. British scientists adopted multidisciplinary
approach to increase the working efficiency
of soldiers during WW-II and called it
‘Ergonomics’
In European nations, it emerged in 1949 to
improve workplaces and jobs in the industries,
with an emphasis on biomechanical
applications.
In North America, it is called as ‘Human
Factors’ or ‘Human Engineering’
In Eastern nations, it is called as ‘Human
Ergology’
Historical Perspective

6. Human-Machine Interaction

7. ERGONOMICS
 Focuses on the scientific study of
relationship between man and his working
environment.
 The environment includes his tools and
materials, method of work, ambient
conditions, physical environment of work
and organization of work.
 Word ergonomics is coined by K. F. H.
Murrell in 1949; ‘ergon’ meaning work,
and ‘nomos’ meaning natural laws
 A philosophy of applying natural laws in
designing for people

8. Components of Ergonomics

9. Ergonomic Implications for development

10. Why Ergonomics Now???
 Most of the hand tools and animal drawn equipment were
fabricated by village artisans.
 The artisans and users (farmers and laborers) were in face-to-
face contact.
 Moreover, majority of the components were made of wood and
user could modify the equipment himself using an axe and
similar tools.
Thus, ergonomics was in application to some
extent in earlier days also.

11. 1. Male Vs. Female
strength
2. Effect of age
3. Muscular
contractions
4. Endurance time and
strength trade-off
5. Design load
6. Third class of lever
Basic Biomechanical Variations

12. Third class of lever
Moment = 10 x 36 + 16 x 17 = 632 N-cm
Muscle holding the lower arm attached 5 cm from the elbow
Force in the muscle (632 / 5) = 126.4 N.
To hold a load of 10 N in the hand, the reactive force in the muscle to hold the hand in
equilibrium would be 12.6 times that of the load

13. Typical areas of Ergonomics
1. Anthropometry
2. Work physiology
3. Biomechanics
4. Physical and ambient environment
5. Drudgery reduction
6. Accidents and safety

14. Anthropometry
 The branch of ergonomics that deals with
body measurements is called anthropometry.
 Anthropometric data is used to determine
the size of handles, height of work surfaces
and space in which operator has to work.
 Anthropometry is comprised of two
components – Osteometry and Somatometry.

15. Anthropometric Data
 Aerospace Medical Research Laboratory,
Dayton, Ohio, USA.
 Ergodata, data bank at anthropology laboratory,
Paris, France.
 Survey of Anthropolocal survey of India (ASI)
in 1961-69 of 30,000 population – Body stature,
body weight and chest circumference.
In 1980, All India bio-anthropolocal survey of
ASI gathered all the relevant information.

16. Anthropometric parameters for
designing agricultural machinery
AICRP on Ergonomics and Safety in Agriculture
covered 79 body dimensions.
For the design and development of agricultural
machinery, it requires at least 79 body
dimensions and 16 strength parameters, totalling
95 parameters.

17. Equipments for measurement
Anthropometer
Spreading Calliper
Vernier Calliper

18. Strategy to design farm tools
 For a designer, it starts from power and
capacity of the tool. For ergonomist, mode of
power is important i.e. muscle power or power
source.
 Determining anthropometric, muscle strength
and physiological data.

19. Body Dimensions - Standing posture

20. Body Dimensions - Sitting posture

21. Data for Agricultural machinery Design
Anthropometric data (79)
Weight Palm length
Stature Thumb length
Eye height Index finger length
Acromial height Middle finger length
Elbow height Ring finger length
Iliocrystale height Thumb breadth
Metacarpal III height Thumb thickness
Grip diameter (inside) Index finger breadth
Popliteal height sitting Index finger thickness
Buttock-popliteal length Hand breadth (metacarpal)
Hip breadth sitting Hand breadth (across thumb)

22. Body dimensions for machine design

23. Contd…

24. Anthropometric data of Indian agricultural workers
CIAE, 2014

25. HAND AND WRIST DEVIATIONS

26. Measurement of hand deviation
Graph paper for measurement of
hand dimensions
Goniometer for measurement of hand
deviation

27. Procedural Methodology
Body dimensions Anil Shyam Jeetendra
Stature
Standing eye height
Acromial height
Acromion to dactylion length
Elbow height
Knee height
Shoulder width
Arm span
Demi span
Half arm span

28. Percentiles give a fair idea whether the measurements are
related to average person or a specific individual whose
dimensions are above or below the average.
Percentile
5th 50th 95th Percentile
Frequency of occurrence of
students of certain height Percentile z value Percentile z value
1 –2.33 99.9 3.09
2.5 – 1.96 99 2.33
5 – 1.64 97.5 1.96
10 – 1.28 95 1.64
25 – 0.67 90 1.28
50 0.00 75 2.67

29. Example
The stature height of an adult male is 1778 mm (5 ft, 10
in.) tall. Mean and standard deviation values of stature of
males is 1756 and 67 mm.
5th Percentile = Mean + Standard deviation x z
5th percentile = 1756 + 67 x -1.64 =1646 mm
95th percentile = 1756 + 67 x 1.64 = 1865 mm

30. 5th and 95th Percentile for Indian male farm workers

31. 5th and 95th Percentile for Indian female farm workers

32. Muscular strength
o It is the maximum force the muscles
can exert isometrically in a single
voluntary effort.
o In agricultural operations, human
workers are used as source of power
and parameters involved are hand grip
strength, arm strength, leg strength and
push/pull capacity.
o Muscular strength depends on race,
body weight and lifestyle.

33. Muscular Strength
Parameter No.
Hand grip strength (right and left) 2
Push and pull strength (standing, sitting) 6
Leg strength right and left (sitting) 2
Foot strength right and left (sitting) 2
Torque strength both hands (standing, sitting) 3
Hand grip torque, sitting 1
TOTAL 16

34. Measurement of Muscular Strength
No. Parameter
1 Handgrip strength (right)
2 Handgrip strength (left)
3 Push strength (both hands), standing
4 Pull strength (both hands), standing
5 Push strength (left hand), sitting
6 Pull strength (left hand), sitting
7 Push strength (Right hand), sitting
8 Pull strength (Right hand), sitting
9 Leg strength (right), sitting

35. Contd…
No. Parameter
10 Foot strength (right), sitting
11 Leg strength (left), sitting
12 Foot strength (left), sitting
13 Torque strength (preferred hand),
standing
14 Torque strength (both hands),
standing
15 Torque strength (both hands), sitting
16 Handgrip torque (preferred hand),
sitting

36. Variation of muscular strength in Indian and North
American population
Strength Parameter Gender India North America
Push force with both hands, N Male 220 372
Female 143 180
Pull force with both hands, N Male 218 267
Female 159 166
Hand grip strength, N Male 347 502
Female 220 319
Strength in elbow flexion, N Male 195 287

37. Maximum muscular strength is in the age group of 25-35 years,
older workers generate 75-85% of younger group. Average
woman produce 2/3 of muscular strength as that of man.
Muscular Strength for Indian and Western workers

38. Physiological: Direct measurement of Energy expenditure

39. Physiological: Indirect measurement of Energy expenditure

40. Heart rate Monitor
 Heart rate (number of ventricular beats per minute) is often
used as an indicator of cardiovascular stress.
When the heart rate exceeds 80% of the age related maximum,
undue stress occurs to a person.
Farm operations and activities Heart Rate
(beats/min.)
Ploughing (Country plough, Mould
board plough)
103 – 131
Digging soil with space, hoe, pick axe 131 – 172
Power tiller rotapuddling 101 – 119
Transplanting seedling manually in
puddled soil
109
Weeding with wheel hoe 114 – 121

41. Oxygen consumption rate
 Maximum aerobic capacity or
maximum oxygen uptake or VO2
max is conceived as an
international standard of cardio-
respiratory fitness.
 In western workers, it ranges
from 3.5 – 4.5 l min-1 and 2 l min-1
for Indian workers.
 For females, VO2 max. is 70-75
% as of that of men.
 This results in less usage of
some implements in Indian
conditions.

42. Optimal work and Rest cycle
A person is operating a tillage tool for 40 minutes and consuming
1.58 l min-1. The VO2 max. of the worker is 3.2 l min-1. The
acceptable workload is 40% of VO2 max.

43. Design of workplace of tractors
S.
No.
Parameter Angle
(degree)
1 Angle of upper arm to vertical 0-35
2 Wrist angle 170-190
3 Elbow angle 80-165
4 Hip angle 95-100
5 Knee angle 110-120
6 Angle of trunk to the vertical 15-25
7 Ankle angle 90-100

44. Design of workplace of tractors

45. Selection of Design parameters

46. Postural Discomfort
Overall body discomfort scale Rated perceived effort scale

47. Most of the injuries are causes due to tractor accidents, such as
overturns, run-overs, power take off and unintended contact
with tractor attachments.
Farm Accidents
SOURCE % OF TOTAL FARM
MACHINERY ACCIDENTS
Tractor & tractor operated implements 31.0
Animal drawn equipment 22.0
Threshers (including winnowers) 14.0
Electric motors/pump sets 12.0
Chaff cutters (manual + power operated) 9.0
Power tillers 6.0
Sprayers (manual + power sprayers) 4.0
Other equipment 2.0
TOTAL 100

48. Tractor Thresher Chaff cutter
Accidental Spots

49. HADDON MATRIX
Phase Host Agent/Vehicle Environment
Pre-event
 Alcohol intoxication
 Gender, weight,
impulsivity
 Awareness about lethality
of pesticides
 Meal before ingestion
 Concentration and
quality of pesticide
formulations
 Safe pesticide storage
 Pesticide
bans/restrictions
 Accessibility of toxic
pesticides
Event
 Alcohol intoxication
 Level of intent
 Dose ingested
 Toxicity of the
pesticide
 Additives affecting
absorption
 Proximity to other
people during attempt
Post-
event
 Help seeding behaviour
 Health, age
 Chronic alcohol use and
dependence
 Genetic factors affecting
pesticide metabolism
 Speed of poisoning
onset
 Effectiveness of
treatment
 Availability and
affordability of
antidotes and
ventilators
 First aid
 Help seeking behaviour
 Access/transport to
hospital care
 Quality/affordability of
health care of hospitals

50. Prevention of accidents in agriculture
Three pronged approach
1. Engineering aspects
 Redesigning of machinery, methods of work
and installing safety guards on machinery
 Designing tractor trailers considering stability
and hitching arrangement
 Proper safety guards of rotating parts
 Incorporate safe design features
 Correct installation

52. Prevention of accidents in agriculture
Three pronged approach
2. Enforcement aspects
 Proper training and mandatory driving
license for drivers.
 Mandatory built-in safety features like
ROPS on tractors, feeding chute in threshers
 Documentation of accidents for
compensation to accident victims

53. Prevention of accidents in agriculture
Three pronged approach
3. Educational aspects
 Introduction of farm safety in course
curriculum at primary state.
 Educating farmers about farm accidents
through public media.
 Encouraging farmers to undergo periodic
training and orientation courses on safe
operation and maintenance of tractors,
sprayers, dusters and threshers.

54. PRACTICAL APPLICATIONS

55. Designing a Wheel Hoe
Handle diameter is cylindrical or slightly oval. The
95th percentile middle finger palm diameter is 32
mm and recommended handle grip diameter is 32
mm.
The total tool height should not be less than eye
height of the worker in standing posture. The 95th
percentile height of male workers is 1646 mm. The
angle of operation is lower than 45 degree. The
acromial height of 95th percentile is 1477 mm and
max. permissible angle is 45 degree. Therefore,
total length is 1477/Sin 45 = 2088 mm. Deducting
elbow grip length of 405 mm. The length of wheel
hoe = 2088 – 405 = 1683 mm. The min. length of
the wheel hoe is 1700 mm.

56. THANK YOU