hougan: anthropometry

Glen Hougan Winter 2010

Human factors - ergonomics


classification


psychological aspects


Visual processes

visual perception of texture

perception of form and shape

colour blindness

visual illusions

visual detection


auditory processes

perception

sensitivity


cutaneous processes

Touch sensitivity

Pain sensitivity

Temperature sensitivity


Taste and olfactory processes


Time perception


Cognitive processes

search

memory

imagery

problem solving

learning

language communication

reading


motor processes

simple movements

tracking movements

speech

movement organization

complex movements


human performance

performance strategies

manual control

attention

reaction time and speed

errors accuracy and reliability


Physiological and anatomical aspects


physiology of the nervous system

Visual sensory systems

Nervous system

Brain function


basic functions

Body temperature regulation

Cardiac processes

Reproductive processes

Respiratory processes


work capacity

dynamic

static


biomechanics posture

muscular strength

dynamic body measurements

static body measurements


group factors

gender

experience and practice

status

Trained versus untrained

pregnancy

Culture and ethnic group

age


individual differences

intelligence

Physical fitness

attitude

personality and temperament

achievement

state of health

ability


Psychophysical state variables

sleep

drugs

fatigue

nutrition

fear

arousal


task related factors stress

task complexity

sensory depravation

monotony and boredom

personal isolation

vigilance


Information presentation and communication


Visual communication


display and control design


environment

illumination > noise > vibration > climate > atmosphere > altitude


Work design and organization

hours of work > training > supervsion > job attitude


HEALTH AND SAFETY


CREATING YOUR OWN TEMPLATE TO UNDERSTAND HUMAN FACTORS


1.  Anthropometry 2.  Biomechanics


the average U.S. woman is 5' 3.7 (162 centimeters) tall and weighs 152 pounds (69 kilograms).

U.S. Department of Health and Human Services


5”4”


Meas. Barbie US Army

height 5’10” 5’4”

Chest circum. 35” 35.7”

Waist circum 20” 31”

Hip circum 32.50” 38.10”

Hip breadth 11.6” 13.49”

Thigh circum 19.35” 22.85”


the average U.S. male stands 5' 9.1 tall and weighs 180 pounds

U.S. Department of Health and Human Services


Meas. Ken US Army

height 6’0” 5’9”

Chest circum. 38.4” 39”

Waist circum 28.8” 35.1”

Hip circum 36” 38.7”

Hip breadth 12.2” 13.46”

Thigh circum 20.4” 23.48”


The NHANES III was a comprehensive survey of the American population during years 1988-1994.


Human variations Intra-individual


Human variations Inter-individual


Human variations Secular variability


Chopsticks

24 male subjects in ages 18-21 that were right-handed

Testing handle diameter with three levels Tip angle with four levels

Each subject asked to do 4 tasks with 2 different combinations


Chopsticks

Food pinching - pick up peanuts from dish and put in cup and number of peanuts were counted within a certain time limit


Chopsticks

Food shearing - grip sponge cake and shear it in two.

Elapsed time was measured


Chopsticks

Food thrusting - thrust 10 pieces of sumulated food into dish and then pick it up.

Elapsed time was measured


Chopsticks

Food pulling - grip a simulated food (eraser) and pull it towards the mouth until it pulled off

Push pull scale was tied to the food.


Chopsticks

Semantic differential scale

4 adjective pairs

1.   Arm aching-arm unaching

2.   Gripping easy - gripping difficulty

3.   Exerting easy - exerting difficulty

4.   Comfortable - uncomfortable

Mark these on a scale of 1 to 9


Chopsticks

Conclusions

Chopstick handle diameter and tip angle have a significant influence on eating efficiency

Optimum chopstick

1.   6 mm handle diameter 2.   2 degree tip angle 3.   4 mm dip diameter 4.   180 - 240 mm long chopsticks (earlier study)


Chopsticks

The optimum length of a chopstick is 210mm (Wu, 1995) and this…

References Wu, Swei-Pi, (1995) Effects of the handle diameter and tip angle of chopsticks on the food serving performance of male subjects. Applied Ergonomics 28 (4), pg. 237-244.


The field of study involving classical mechanical principles and their relationships as used or applied to living organisms or biological tissues in motion.

i.e. body movement and bone strain.

• 


Biomechanics of Sport and Exercise


Motor Control


Muscle


Gait and Locomotion


Biomedical Engineering


Orthopaedics


Orthotics and Prosthetics


Gait and Locomotion

Biomedical Engineering

Motor Control

Orthotics and Prosthetics

Orthopaedics

Muscle

Biomechanics of Sport and Exercise


Snow shovelling


Heart attacks

Similar to weight lifting Lots of exertion not much movement Raises blood pressure and heart attack

Multi-joint movement Small muscles in the lower back Large leg muscles

Shoveling snow can cause disc compression (Hansson & Oberg, 1996)

Repetitive motion increases risk of injury


Posture Upright erect stance with feed wide apart

Warm up - warm down Stretching

Clothes Don’t over dress


Freivalds, A (1986). The ergonomics of shovel design - a review of literature. Ergonomics 29 (1): 3-18

1.   Blade - plastic, aluminum, or steel?

•  Steel - most durable but heaviest •  Aluminum - lighter but softer (although can have steel edge) •  Plastic - lightweight but abrade quickly


Freivalds, A (1986). The ergonomics of shovel design - a review of literature. Ergonomics 29 (1): 3-18

1.   Blade - plastic, aluminum, or steel?

•  Steel - most durable but heaviest •  Aluminum - lighter but softer (although can have steel edge) •  Plastic - lightweight but abrade quickly

Plastic

•  Lighter the shovel the easier it will be to lift.


1.   Blade size - what are the issues?

•  taller and heavier people blades should be 18” x 16” •  shorter and lighter person the blades should be 16 1/2” x 14 1/2”

18” blades take up 3/4 of sidewalk and are optimum for maximizing the load


1.   Shaft length - what are the issues?

•  taller and heavier people the shaft should be 52” with a 1 1/4” handle •  shorter and lighter person the shaft should be 42” and 1 1/2 handle

Relatively longer shaft will reduce operators trunk flexion

However, maximum force at the right erector spinae muscle is increased

What can one do?

Make shaft adjustible


•  The shaft should be angled at 60 degrees towards the bottom of the shaft and 35 degrees for the upper portion of the shaft.

•  The bend should occur at the 2/3 mark of the shaft (measuring from the top)


Handle - what are the issues?

•  Handle should allow user to grip with mittens - cushioned D grip

•  Handles should be made out of fibre glass


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HEAD WIDTH 7.2 in

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Sarah OrfordDSGN 3210January 20, 2010


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KATE MITCHELLDSGN 3010 - HUMAN FACTORSJANUARY 20, 2010

hougan: anthropometry

Design

measuredglen hougan

speedglen hougan winter

safetyglen hougan winter

biomechanicsglen hougan

elapsed time

department of health

hip breadth

chopsticksfood thrusting