Director
ICAR - Central Institute for Women in Agriculture
Bhubaneswar - 751003, Odisha, India

Pratap Ergo Tools

Anthropometric Data

Deals With the measurements of the dimensions and certain other physical characteristics of the body such as volumes, centre of gravity ,inertial properties and masses of body segments. Anthropometrics is the comparative study of human body measurements and properties.

S No. Dimension Value
1 Stature
10 Sitting Shoulder Height
11 Sitting Elbow Height
12 Thigh Clearance
13 Buttlock-Knee Length
14 Buttlock Popliteal Length
15 Sitting Knee Height
16 Pop Liteal Height
17 Shoulder breadth (bideltoid)
18 Shoulder breadth (biacromial)
19 Hip breadth
2 Eye Height
20 Chest (bust) depth
21 Abdominal depth
22 Shoulder-elbow length
23 Elbow-fingertip length
24 Upper limb length
25 Shoulder-grip length
26 Head length
27 Head breadth
28 Hand length
29 Hand breadth
3 Shoulder Height
30 Foot length
31 Foot breadth
32 Span
33 Elbow span
34 Vertical grip reach (standing)
35 Vertical grip reach (sitting)
36 Forward grip reach
4 Elbow Height
5 Hip Height
6 Knuckle Height
7 FingerTip Height
8 Sitting Height
9 Sitting Eye Height

What are the parameters of anthropometry? Parameters of anthropometry Age dependent factors:- a) Weight b) Height c) Head circumference d) Chest circumference Age independent factors:- a)Mid- arm circumference (1-5 years) b) Weight for height c) Skinfold thickness d) Mid upper arm/height ratio.

  • Literally, 'The measure of man'
  • Quantifies human variability
  • Physical Measures, height, weight, reach, length, width, depth, circumference, surface area, etc
  • Strength, dexterity, range of motion

We are not all the same size.

  • Exclude as few as possible.
  • Let the small person reach, let the large person fit.
  • Poor design for mechanical abilities of the human body can lead to discomfort or injury, e.g., the height of keyboard for a computer.
  • Sources of Anthropometry, Data, Text, Ergo software, Tables in books in the HF/SQC lab (215)

Example Anthropometric Data

  • Static Measures
  • Passive measures of the dimensions of the human body.
  • These measures are used to determine size and spacing requirements of work space.
  • Example Measures arm length (e.g., your lab …), height, weight, wing span, seat to elbow height.
  • More Anthropometric Data
  • Dynamic Measures
  • Measures of the dynamic properties of the human body, such as strength and endurance
  • These measures are used to match the dynamic characteristics of controls to user.
  • Measures
  • Range of motion for various joints
  • Force of leg pushes
  • Strength of fingers

How?

  • Populations
  • Tools & techniques
  • Statistical calculations
  • Based on central limit theorem, typical calculations, mean, standard deviation, percentiles
  • Estimate for normal distribution

An Example … A study was performed to determine key anthropometric measures of school-aged children to be used in the design of playground equipment. Based on a sample size of 1050, the vertical reach of 7-year old boys was found to have a mean of 57.1 inches and a standard deviation of 3.3 inches. • 5th percentile = ___________________ (z = ______) • 50th percentile = ___________________ (z = ______) • 95th percentile = ___________________ (z = ______)

Using Anthropometric Data

  • Know your population
  • If your measures are from a different group than your users are from problems could result.
  • Women are different from men.
  • Asians are different from Europeans.
  • Use Recent Data
  • Changes in diet and habit lead to changes in size and fitness of population
  • Most size measures are done on nude or lightly clothed subjects.
  • Clothes change our sizes
  • Think of seat belts in summer vs. winter.

Using Anthropometric Data

  • Understand the task
  • How will the system or device be used?
  • Reach, fit, & strength requirements
  • Cautions about adding segments.
  • Every measure contains variability
  • st2 = s12+ s22+ s32+ .....+ Snn the nth percentile person is not composed of nth percentile segments.

Using Anthropometric Data

  • ("Let the small person reach …") If you were designing a console requiring a forward reach to activate a control, what reach distance would you use to define your maximum console depth?
  • ("Let the large person fit …") What is the minimum height of the bottom of the console if the operator is seated?

Percentile formula helps in determining the performance of a person in comparison to others. To recall, the percentile is used in tests and scores of a candidate to show where he/she stands with reference to other candidates. The percentile of the value ‘x’ is calculated by the ratio of the number of values below ‘x’ to the total number of values. Percentile calculation can be done for weight, income and many other things.

The Percentile Formula is given as,

Percentile = (Number of Values Below “x” / Total Number of Values) × 100

Also Check: Percentage Formula

Another formula to find the percentile is given by:

P = (n/N) × 100

P = (nth percentile/100)  × Total number of values in the list

Here, 

n = Ordinal rank of the given value or value below the number

N = Number of values in the data set 

P = Percentile 

Rank = Percentile/100

Ordinal rank for Percentile value = Rank × Total number of values in the list

Solved Example

Question 1:

The scores for student are 40, 45, 49, 53, 61, 65, 71, 79, 85, 91. What is the percentile for score 71?

Solution:

Given,

No. of. scores below 71 = 6

Total no. of. scores = 10

The formula for percentile is given as,

Percentile = (Number of Values Below “x” / Total Number of Values) × 100

Percentile of 71

= (6/10) × 100

= 0.6 × 100 = 60

Question 2: 

Consider the list {50, 45, 60, 25, 30}. Find the 5th, 30th, 40th, 50th and 100th percentiles of the list given.

Solution:

Given list – 50, 45, 60, 25, 30

Ordered list – 25, 30, 45, 50, 60

N = 5

Percentile (P) Ordinal rank Percentile value
5th (5/100) × 5 = [0.25] = 1 1st number in the ordered list = 25
30th (30/100) × 5 = [1.5] = 2 2nd number in the ordered list = 30
40th (40/100) × 5 = 2 2nd number in the ordered list = 30
50th (50/100) × 5 = [2.5] = 3 3rd number in the ordered list = 45
100th (100/100) × 5 = 5 5th number in the ordered list = 60