1. Chapter 5: Workplace, Equipment and Tool Design
Presented by
Andira

2. Chapter 5 Focuses on: Design of Tools and Equipment to fit Human Constraints
Work Processes
Operations
Work environment
Tools

3. Goal of Chapter 5 Does FOCUS on:
Principles of work design
Check lists for design
Does NOT focus on underlying theory of physiology and human limitations, (Can get that in:
KIN Human Motor Control and Learning
KIN Motor development

4. Key points Fit tools and equipment to operator Provide adjustability
Maintain neutral postures
Minimize repetitions
Use “power grips” for high-force tasks
Use pinch grips for precision tasks

5. Outline of Chapter 5 Anthropometry and design:
Design for extremes, for average, etc.
Principles of work design: workplace
Focus on design of seating
Principles of work design: machines and equipment
Cumulative Trauma Disorders (CDT)
Principles of work design: (hand) tools.

6. I. Anthropometry and Design
Anthropometry: the science of measuring the human body,
Ergonomics: designing the workplace, tools, equipment, work environment and operations to fit the human operator.
Anthropometric data: Table 5-1(pg. 184) shows data on a typical human population; this data is invaluable in design.

7. Approaches to Design
Design for Extremes: design to accommodate the max and min dimensions of the population, or perhaps the 5th to the 95th percentile.
Design for Adjustability: make designs adjustable to fit different sized individuals.
Design for the Average: design to suit the average person, and not be too bad for most people.

8. II. Principles of work design: workplace
Use elbow height to determine work surface height.
Adjust the work surface height based on the task
Provide a comfortable chair
Provide adjustability in the seat
Encourage postural flexibility
Provide Anti-fatigue mats for a standing operator
Locate all tools and materials within the normal working area
Fix locations for all tools and materials
Use gravity bins and drop delivery
Arrange everything to minimize motions

9. 1. Use elbow height to determine work surface height

10. 3. Provide a comfortable chair Example: Aeron Chair Images from: http://www.ultimatebackstore.com/

11. Being seated flattens the lordotic arch (lumbar region)

12. Balans chair: straightens pelvis

13. Encourage Postural Flexibility: gets blood supply to discs

14.    
Exercise Ball Chairs

15. The bean bag chair

16. Ergonomic pros and cons of the bean bag chair
Conforms to the shape of each person
Moves with the person
Relatively low cost ($80 - $200)
Cons:
Not suitable for office work – not enough structure to provide back support for computer or desk work,
Hard for old people to get out of chair,
Informal: not appropriate seating if you are having the Queen of England to tea.

17. Could this be the solution?

18. Other Bean Bag furniture
Bean bag tables

19. 7. Locate all tools and materials within normal working area

20. 7. Locate all tools and materials within normal working area (cont)

21. III. Principles of work design: Machines and equipment
Use a fixture (instead of the hand)
Locate control devices for best accessibility and strength
Use shape, texture and size to code controls
Use proper control knob size, displacement and resistance
Insure compatibility between controls and displays

22. VI. Cumulative Trauma Disorders (CDT) or repetitive motion injuries
National Safety Council (1997) says that 15 – 20% of workers in key industries are at risk for CTD (meat packing, poultry, auto and garment industries)
61% of all occupational illnesses are associated with repetitive motions (butchering and manufacturing are worst)
There are approximately 2 CTD claims per 1000 $30K pre case.

23. Cumulative Trauma Disorders are:
Common
Widespread in many industries
Expensive
Painful,
Disabling
Design work, tools and equipment to avoid them!!

24. Examples of CTD: Carpal tunnel syndrome Tennis elbow Bursitis
Trigger finger

25. Carpal Tunnel Syndrome

26. Factors leading to development of CTD
Excessive force
Awkward or extreme joint motions
High repetition
Duration of work

27. Symptoms of CTD Pain Restricted movement Tissue swelling
Numbness (if nerves are involved)
CTD comes on slowly, gradual development, often ignored.
CTD can lead to permanent disability

28. V. Principles of work design: (hand) tools
Use power grip for tasks requiring force
Use pinch grips for tasks requiring precision
Avoid prolonged static muscle loading
Perform twisting motions with elbows bent
Maintain a straight wrist
Avoid tissue compression
Design tools to be used by either hand
Avoid repetitive finger motions
Use strongest working fingers: middle and thumb
Design 1.5” handle diameters for power grips
Design handle lengths to be a minimum of 4”

29. Grips: power, pinch, hook, press

30. 9. Use strongest working fingers

31. 10. Design 1.5” handle diameters for power grips
Good grips products: originally designed for
the handicapped, but good for everyone.

32. V. Principles of work design: hand tools (continued)
Design a 3” grip span
Design appropriately shaped handles
Design grip surface to be compressible and non-conductive
Keep the weight of the tool below 5 lbs.
Use gloves judiciously
User power tools instead of hand tools (e.g. screw drivers, etc)
Use proper configuration and orientation of tools
Choose a power tool with proper characteristics

33. 12. Design a 3” grip span

34. 13. Design Appropriately Shaped Handles

35. 18. Use proper configuration and orientation of tools