Anatomy Biomechanics Work Physiology. Musculoskeletal Anatomy and Musculoskeletal Injuries

Transcription

1 Chapter 2 (2[1] 2[4]) Anatomy Biomechanics Work Physiology 1 Musculoskeletal Anatomy and Musculoskeletal Injuries Skeletal System Spine Upper extremity Lower extremity Joints Tendons Muscles Nerves 2

2 Vertebral Column/Spine Source (Left): Wikimedia Commons, accessed 19 Jan 10. Source (Right): Konz & Johnson, Work Design, 6 th edition. 4

3 Vertebrae, Side-View 5 Source (Right): Wikimedia Commons, accessed 19 Jan 10. Vertebrae/Disk, Oblique View 6 Source: Wikimedia Commons, accessed 19 Jan 10.

4 Vertebra Cross-Section (cervical vertebra) 7 Source: Wikimedia Commons, accessed 19 Jan 10.

5 Shoulder 9 Source: Wikimedia Commons, accessed 19 Jan 10. Wrist Palmar/Volar (palm-side) View Dorsal (back-side) View Source (Left): Wikimedia Commons, accessed 19 Jan 10. Source (Right): Wikimedia Commons, accessed 19 Jan

6 Wrist Cross-Section 11 Source: Wikimedia Commons, accessed 19 Jan 10. Lower Extremity 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. 12

7 Joints 13 Ball and Socket Joint (Shoulder) 14 Source: Wikimedia Commons, accessed 19 Jan 10.

8 Hinge Joint (Knee) 15 First-class lever Fulcrum in the middle (e.g. seesaw) 16 Source: Konz & Johnson, Work Design, 6 th edition.

9 Second-class lever Fulcrum at one end (e.g. wheelbarrow) 17 Source: Konz & Johnson, Work Design, 6 th edition. Third-class lever Fulcrum at one end, resistance has mechanical advantage (e.g. forceps) 18 Source: Konz & Johnson, Work Design, 6 th edition.

10 Muscles in synovium 19 Nervous System 20 Source: Wikimedia Commons, accessed 19 Jan 10.

11 Neuromuscular Unit 21 Muscle Force Forces (kg) exertable on a vertical handgrip with the right arm at various elbow angles: Pull Push

12 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 23 Cardiovascular Anatomy (Engineer s Schematic) 24

13 Metabolism Definition Transformation: chemical energy work Units of Measurement kilocalorie (kcal) 1 kcal = 1000 cal = 1 Cal = heat required to raise 1 liter H 2 O from 15 C to 16 C 25 Alternative Units Common rate units: kcal/min Text rate units: W 1 W kcal/min 1 kcal/min 73 W Note: 1 W/kg x 70 kg x kcal/min text typical slides units male units 26

14 Metabolism (1) carbohydrates glucose glycolysis pyruvic acid fats fatty acids oxidation acetic acid proteins digestion amino acids deamination deaminated AAs 27 Metabolism (2) carbohydrates glucose glycolysis pyruvic acid fats fatty acids oxidation acetic acid proteins digestion amino acids deamination deaminated AAs CO 2 energy H 2 O 28

15 Metabolism (3) carbohydrates glucose glycolysis pyruvic acid fats fatty acids oxidation acetic acid proteins digestion amino acids deamination deaminated AAs CO 2 adenosine triphosphate energy H 2 O adenosine diphosphate + PO 4 creatine + PO 4 creatine phosphate 29 Metabolism - Components Total Metabolism = Basal Metabolism (life support) + Activity Metabolism (work, leisure) 30

16 Basal Metabolism, Resting Metabolism Male ( 70 kg ) 1700 kcal/day 1.2 kcal/min Female ( 60 kg ) 1400 kcal/day 1.0 kcal/min Factors: Sex Size Age Resting metabolism ~10% - 15% higher 31 Metabolism Response to Exercise Factors Affecting Energy Expenditure Measurement 32

17 Energy Cost of Work (Activity Standards) Type of Work kcal/min light assembly 1.6 medium assembly 2.7 bricklaying 4.0 pushing wheelbarrow (115 lb load) 2.5 sawing wood 6.8 chopping wood 8.0 shoveling (16 lb loads) 8.5 climbing stairs with 17 lb load, suspended 9.0 climbing stairs with 22 lb load on shoulder Grades of Physical Work (Activity Standards) Grade of work kcal/min kcal/day (8 hr) heart rate (beats/min) O 2 (l/min) rest (sitting) 1.5 < very light light moderate heavy very heavy unduly heavy > 12.5 > 6000 > 180 >

18 Recommended Limits 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 < Rest Requirements R = rest time T = total working time K = work metabolic rate S = standard metabolic rate 36

19 Rest Requirements: Example 1 T = 60 min K = 6 kcal/min S = 4 kcal/min 37 Rest Requirements: Example 2 T = 60 min K = 10 kcal/min S = 4 kcal/min 38