Engineering Anthropometry

1
Engineering Anthropometry

• Anthropometry the study of human body
  dimensions
• Imagine you are positioning an emergency "rip
  cord" on a train. How high up should you put it?
  So people can reach it! is the obvious (and
  correct) response. One way to arrive at an answer
  is to ask your friends to give it a try. But to
  get values that are in any way robust (especially
  if the product is to be used by different
  nationalities), it is necessary to turn to the
  science of anthropometrics.
• Example Im 68 inches tall
• In USA/UK, Id be in the 35-40th percentile
• In Japan, Id be in the 75-80th percentile
• Links to look at
• Anthropometry Resource Center
• People with Disabilities
• Dates back to ancient Egypt
• Cubit (52 cm) based on human dimensions
  (distance from elbow to tip of longest finger)
• Large scale anthropometrical surveys are
  expensive and time consuming
• Typically do specialized surveys on key
  dimensions

2
CAESAR Research Project

• CAESAR A 3-D anthropometric research project
  that will generate technologically advanced data
  on the size and shape of the modern human body.
• The companies supporting this 6 million project
  include Boeing, Caterpillar, GM, John Deere,
  Levi Strauss, Magna Interior Systems Engineering,
  Navistar, Sears, Transport Canada, Visteon, Case
  Corp. Ford, Jantzen, Johnson Controls, Lee
  Company, Lockheed Martin Aeronautical, Mitsubishi
  Motors, Nissan Motors, Sara Lee Knit Products,
  and Vanity Fair, Inc.
• Collecting the measurements of 10,000 people,
  ages 18 to 65, at eight sites in the U.S. and in
  Europe.
• Expected to be completed Fall 2000.

3
Wright-Patterson (USAF) Involvement

• The tests will use equipment from Cyberware,
  (Monterey, Calif.) that was originally developed
  for a Wright-Patterson Air Force Base program
  called Computerized Anthropometric Research and
  Design (CARD).
• The Air Force used it to develop a means of
  determining if its clothing and tools were the
  most effective size and shape, and that pilot
  stations within aircraft were the most efficient
  possible.

4
Whole Body Scanner

• Other sites
• http//www.industry.net/discussions/Features/caesa
  r_measure.htm
• http//www.af.mil/news/May1998/n19980520_980697.ht
  ml
• Whole Body Scanner

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Engineering Anthropometry for Design

• Design
• Clothing
• Workspace
• Environment
• Equipment, tools, machinery
• Consumer product design
• Design Idea
• Accommodate the body characteristics of the
  population
• Universal operability is 90-95 of the population
• Build in adjustment to meet objectives
• Some dimensions only require one set of
  dimensions
• Example 95 reach

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Measurement Devices

• Calipers spreading and sliding
• Anthropometer rods with one fixed
• Tapes measure circumferences and contours
• Simple scales weight
• Cones and boards with holes grip circumference
  and finger size
• Photographic
• Electronic scanners

7
Human Variability

• Is there a Average Human?
• Humans vary in dimensions based on
• Gender
• Ethnic groups
• Nationalities
• Etc.
• Over 300 anthropometric measurements on the body
• It is hard to say that any one person is 50-tile
  on all measurements
• Factors affecting Anthropometric data
• Age body dimensions begin to increase with age
  and then decrease around 40
• Gender men are generally larger than women at
  any given percentile and body dimensions except
  hips and thighs
• Ethnic differences cause further differences
• Body Position
• Posture affect size
• Clothing clothing adds to body size plus
  restricts movement

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Design and Use of Anthropometric Data

• Design for the Extreme -- An attempt to
  accommodate all (or nearly all) of the population
• Design for the maximum if maximum value
  accommodates all (e.g., height of door, escape
  hatch in airplane)
• Design for the minimum if minimum value
  determines if all are accomodated (e.g., distance
  to control button from the operator (reach)
  amount of force to press a button)
• Design for Adjustable Range design to
  accommodate all (e.g., office chairs, desk
  height, key board height)
• Range typically is 5th percentile of females to
  the 95th percentile of males in relevant
  characteristics
• Design for the Average there is no average
  human
• There are times when the average may be
  acceptable (e.g., counter height at grocery
  store)

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Design and Use of Anthropometric Data

• Design Principles Discussion
• Setting limits to 5th and 95th percentiles can
  eliminate a fairly high percentage of population
• Bittner (1974) looked at 5th and 95th
  percentiles on 13 dimensions
• Would have excluded 52 of population instead of
  10 implied by percentiles
• Why? body measurements are not perfectly
  correlated
• Short arms ? short legs
• To derive composite measures taking into account
  imperfect correlations requires regression
  analysis

10
Design and Use of Anthropometric Data

• General approach
• Determine body dimensions important in the design
• Example chair
• popliteal height (lower leg length), seat depth
  (buttock to popliteal length)
• hip breadth, midshoulder sitting height (back
  height), elbow height, lumbar height
• lumbar depth
• Define population (e.g., adult - male, adult -
  female, children)
• Determine what principle should be applied
• Select of population to be accommodated
• Locate anthropometric tables appropriate for the
  population
• If special clothing worn add allowances
• Build prototype and test using representative
  tasks
• Anthropometric data
• Structural dimensions taken in standard still
  positions
• Functional dimensions obtained in various work
  postures

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Percentile Covered

• Herman Miller found that chairs theoretically
  designed to fit the 5th-percentile female to the
  95th-percentile male actually fit far fewer
  people (Dowell, 1995a).

Return
Source Herman Miller Workplace Research
http//www.hermanmiller.com/research/essays/aerone
ssay2/essay2.html
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Anthropometric Data - structural
Source OSHA Draft Ergonomics Standard (Appendix
D)
13
Anthropometric Data - structural
Source OSHA Draft Ergonomics Standard (Appendix
D)
14
Anthropometric Data - dynamic

• Modeling Reach Distance

Source NASA
15
Anthropometric Data - dynamic
Source NASA
16
Software

• Mannequin (Humancad, Melville, NY) and Jack
  (Center for Human Modeling and Simulation,
  University of Pennsylvania, Philadelphia, PA)
  enable designers to determine the best digital
  reach zone

Example from JACK Source http//www.cis.upenn.edu
/hms/jack.html