IE 366
Chapter 2 (2[1] – 2[4])
Anatomy
Biomechanics
Work Physiology
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Musculoskeletal Anatomy and
Musculoskeletal Injuries
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Skeletal System
Spine
Upper extremity
Lower extremity
Joints
Tendons
Muscles
Nerves
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Vertebral Column/Spine
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Source (Left): Wikimedia Commons, http://en.wikipedia.org/wiki/File:Illu_vertebral_column.jpg, accessed 19 Jan 10.
Source (Right): Konz & Johnson, Work Design, 6th edition.
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Vertebrae, Side-View
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Source (Right): Wikimedia Commons, http://en.wikipedia.org/wiki/File:Gray301.png, accessed 19 Jan 10.
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Vertebrae/Disk, Oblique View
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Source: Wikimedia Commons, http://en.wikipedia.org/wiki/File:ACDF_oblique_annotated_english.png, accessed 19 Jan 10.
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Vertebra Cross-Section
(cervical vertebra)
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Source: Wikimedia Commons, http://en.wikipedia.org/wiki/File:Cervical_vertebra_english.png, accessed 19 Jan 10.
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Shoulder
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Source: Wikimedia Commons, http://en.wikipedia.org/wiki/File:Gray326.png, accessed 19 Jan 10.
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Wrist
Palmar/Volar (palm-side) View
Dorsal (back-side) View
Source (Left): Wikimedia Commons, http://en.wikipedia.org/wiki/File:Gray334.png, accessed 19 Jan 10.
Source (Right): Wikimedia Commons, http://en.wikipedia.org/wiki/File:Gray335.png, accessed 19 Jan 10.
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Wrist Cross-Section
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Source: Wikimedia Commons, http://en.wikipedia.org/wiki/File:Gray422.png, accessed 19 Jan 10.
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Lower Extremity
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Legs
– Unequal leg lengths can cause back pain.
– Leg structure causes sway and forwardbending moment.
Most problems are in ankle and foot.
– Ankle injuries result from inward or external
rotation of foot.
– 80% of foot fractures involve the toes.
– Heel pad is an important shock absorber.
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Joints
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Ball and Socket Joint
(Shoulder)
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Source: Wikimedia Commons, http://en.wikipedia.org/wiki/File:Gray327.png, accessed 19 Jan 10.
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Hinge Joint (Knee)
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First-class lever
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Fulcrum in the middle
(e.g. seesaw)
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Source: Konz & Johnson, Work Design, 6 edition.
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Second-class lever
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Fulcrum at one end (e.g.
wheelbarrow)
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Source: Konz & Johnson, Work Design, 6th edition.
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Third-class lever
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Fulcrum at one end,
resistance has
mechanical
advantage (e.g.
forceps)
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Source: Konz & Johnson, Work Design, 6 edition.
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Muscles
in synovium
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Nervous System
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Source: Wikimedia Commons, http://en.wikipedia.org/wiki/File:Nervous_system_diagram.png, accessed 19 Jan 10.
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Neuromuscular Unit
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Muscle Force
Forces (kg) exertable on a vertical handgrip
with the right arm at various elbow angles:
60
90
120
150
180
28.6
40.0
47.3
55.5
54.5
Push 41.8
39.1
46.8
55.9
62.7
Pull
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Work Physiology
“An aspect of industrial engineering that takes into
account metabolic cost, measurement and
prevention of work strain, and other ergonomic
factors in the design of tasks and workplaces.”
Answers.com
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Cardiovascular Anatomy
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(Engineer’s Schematic)
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Metabolism
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Definition
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Transformation: chemical energy
work
Units of Measurement
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kilocalorie (kcal)
1 kcal = 1000 cal = 1 Cal
= heat required to raise 1 liter H2O
from 15 °C to 16 °C
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Alternative Units
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Common rate units: kcal/min
Text rate units: W
1 W ≈ 0.014 kcal/min
1 kcal/min ≈ 73 W
Note:
1 W/kg x 70 kg x 0.014 ≈ 1kcal/min
text
units
typical
male
slides
units
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Metabolism (1)
carbohydrates
glucose
fats
fatty acids
proteins
amino acids
glycolysis
oxidation
pyruvic acid
acetic acid
deamination
digestion
deaminated AAs
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Metabolism (2)
carbohydrates
glucose
fats
fatty acids
proteins
amino acids
glycolysis
oxidation
pyruvic acid
acetic acid
deamination
digestion
deaminated AAs
CO2
energy
H2O
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Metabolism (3)
carbohydrates
glucose
fats
fatty acids
proteins
amino acids
digestion
glycolysis
oxidation
deamination
pyruvic acid
acetic acid
deaminated AAs
CO2
energy
adenosine triphosphate
H2O
adenosine diphosphate + PO4
creatine + PO4
creatine phosphate
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Metabolism - Components
Total Metabolism =
Basal Metabolism (life support)
+
Activity Metabolism (work, leisure)
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Basal Metabolism, Resting
Metabolism
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Male ( 70 kg )
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1400 kcal/day ≅ 1.0 kcal/min
Factors:
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1700 kcal/day ≅ 1.2 kcal/min
Female ( 60 kg )
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Sex
Size
Age
Resting metabolism ~10% - 15% higher
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Metabolism
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Response to Exercise
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Factors Affecting Energy Expenditure
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Measurement
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Energy Cost of Work (Activity
Standards)
Type of Work
kcal/min
light assembly
medium assembly
bricklaying
pushing wheelbarrow (115 lb load)
sawing wood
chopping wood
shoveling (16 lb loads)
climbing stairs with 17 lb load, suspended
climbing stairs with 22 lb load on shoulder
1.6
2.7
4.0
2.5
6.8
8.0
8.5
9.0
16.2
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Grades of Physical Work
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(Activity Standards)
Grade of work kcal/min
rest (sitting)
very light
light
moderate
heavy
very heavy
unduly heavy
1.5
1.6 - 2.5
2.5 - 5.0
5.0 - 7.5
7.5 - 10.0
10.0 - 12.5
> 12.5
kcal/day
(8 hr)
heart rate
(beats/min)
O2
(l/min)
<720
768 - 1200
1200 - 2400
2400 - 3600
3600 - 4800
4800 - 6000
> 6000
60-70
65-75
75 - 100
100 - 125
125 - 150
150 - 180
> 180
0.3
0.3 - 0.5
0.5 - 1.0
1.0 - 1.5
1.5 - 2.0
2.0 - 2.5
> 2.5
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Recommended Limits
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Energy Expenditure (kcal/min, average)
8-hour shift
4-hour shift
Male
< 5.00
< 6.25
Female
< 3.35
< 4.20
Heart Rate (beats/min, average)
Arm work
< 99
Leg work
< 112
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Rest Requirements
R = rest time
T = total working time
K = work metabolic rate
S = standard
metabolic rate
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Rest Requirements:
Example 1
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T = 60 min
K = 6 kcal/min
S = 4 kcal/min
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Rest Requirements:
Example 2
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T = 60 min
K = 10 kcal/min
S = 4 kcal/min
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