anthropometry - ridwan prasetyo's academic...

AnthropometryRidwan Prasetyo

Today’s menu…

• Definition and the importance

• Anthropometric data

• Design paradigm and strategy

• Class activity: Practicing scientific design

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Definition…

• Anthropos = humans

• Metrikos = measurement

• Literal meaning = measurement of humans

Easy, isn’t it?9/30/2016 Anthropometry 3

More formal definition (maybe for exam)…

Measurement of the dimensions and certain other physical characteristics of the body such as volumes, centers of gravity, inertial properties, and masses of body segments (Sanders & McCormick, 1992)

Too long and difficult?

The study and measurement of human body dimensions(Wickens, et al., 2004) I love this definition!

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Why is it important?

Because God creates us in various and different sizes and shapes: due to age, sex, ethnic, nutrition, etc.

So what?

Physical characteristics of people need to be taken into account in designing anything that people will use Make sense?9/30/2016 Anthropometry 5

Anthropometric data

• What to measure?

• Whom to measure?

• How to measure?

• How to use the data?

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What to measure…?

• Mainly static body dimensions

• Several advance measurements can also be performed e.g. dynamic and Newtonian body dimension we don’t discuss these two in this class. Don’t worry!

• Which body parts?

Anything that you need

Principle: the more you get, the better it would be!

Some expert made standardization very helpful!

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Static body dimensions: Standing & sitting (based on Chuan, et al., 2010)

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Static body dimensions: Standing & sitting(based on Chuan, et al., 2010)

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More complete anthropometric data?

National Aeronautics and Space Administration (NASA)

please take a look at: https://msis.jsc.nasa.gov/sections/section03.htm

But they don’t show all they have

Some anthropometric data are commercialized priced more than $10,000

Fortunately, Indonesia has it! Take a look at:

http://antropometriindonesia.org/index.php/detail/artikel/4/10/data_antropometri

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Whom to measure?

• Sample from population

• Population of what?

Of the potential users of your design

• How many for the ideal sample?

It’s difficult to specify

The more people you take, the more precise it would be!

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How many sample?• Based on Krejcie & Morgan’s (1970) formula

• It has been too old, more than 40 years ago!

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How to measure?

Using special anthropometric apparatus/tools:

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Using anthropometric dataRemember this thing?

Please review your statistics module again9/30/2016 Anthropometry 14

Let’s make this easier…

• Anthropometric data tends to follow “bell curve shape”

• So we can predict certain distribution from the data

• Commonly used distribution in anthropometric data: 5th, 50th, 95th percentile (Adams, 2015)

• 5th percentile means: 5 percent of population is on the value or below the value

• Example: 5th percentile of weight of Indonesian population is 40kg. It means that there are 5 percent of the population whose weight is 40kg or less than 40kg

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Confusing?

• 5th and 95th percentile is considered “extreme member” of a population

• 5th percentile smallest, shortest, lightest people in a population

• 95th percentile biggest, tallest, heaviest people in a population

• Percentile coverage of population

• Example: using 95th percentile value covering 95% of population

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Anthropometric data example…Anthropometric data of Indonesian women(*):

(*) taken from http://antropometriindonesia.org/index.php/detail/artikel/4/10/data_antropometri9/30/2016 Anthropometry 17

Enough for the anthropometric data, let’s move on to….Design paradigm and strategy (Sanders & McCormick, 1992):

• Design for extreme (5th or 95th percentile)

• Design for adjustability

• Design for average be careful…!

Main principle in design: to accommodate as many people as possible but you have specify the population first

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Design for extreme

• Using 5th and 95th percentile as reference

• Don’t forget: male and female are different!

• Anthropometric data always come with two sets of data: male data and female data

• Man generally larger than women in most dimensions

• Example:

95th percentile: Let the tallest people enter the door

5th percentile: Let the shortest people reach the button

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If you’re designing a door…

• What is the value for the door’s height you will use?

Steps:

Which body dimensions? Height, span, or what?

Which percentile? 5th, 50th, 95th?

Which data sets? Male or female?

Now you get the value….

Remember this: “If the tallest people can pass the door, then the shorter people will definitely have no problem”.

male female

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If you’re designing a button (e.g. in cockpit)…• What is the value of the distance from users’ position to the button?

Similar steps:

Which body dimensions? Height, span, or what?

Which percentile? 5th, 50th, 95th?

Which data sets? Male or female?

Now you get the value….

Remember this: “If people with shortest arms can reach the button, then people with longer arms will definitely have no problem”.

male female

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Design for adjustability

• For me, this seems to be the most ideal

• Can also accommodate the most extreme people e.g. wheelchair users, very small persons, etc.

• But, this design strategy can not be applied in every situations

• This is the most ideal, but the most costly

• Imagine…you’re designing an ATM using this design strategy

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Design for adjustability….?

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Design for average

• Be careful with this strategy

• There are no people whose body dimensions are all at the 50th percentile (Hedge, 2013)

• People with short arms don’t necessarily have short legs, etc.

• Using 50th percentile for certain design parameters can accommodate many people in population

• But, using 50th percentile (sometimes) means that you only cover 50% population

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Design allowances (Pheasant & Haslegrave, 2005; Grandjean, 1997)

• Anthropometric measurements refer to a naked person (or lightly clothed)

• In daily situation, we don’t go to office or campus naked or barefoot

• Two design allowances to be considered: SHOES and CLOTHING

• Shoes apply anywhere

• Clothing usually in cold regions

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Design allowances…

CLOTHING

SHOES

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Class activity

• Make a group consisting of max. 4 students

• There are 52 (registered) students here, so we should have 12 groups with 4 students each

• You all act as a designer and your client ask you to design an ergonomic chair

• The task is easy: you only need to determine measurements of the chair

• I will give you the paperwork after you’re done with the grouping

• Put your names and NIMs in the paperwork

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