Anthropometry Flashcards
means “measurement of people”.
Anthropometry
is the study of the size, shape and strength of the human body, including, mass, volumes, mobility, proportions, centers of gravity, and inertial properties of the whole body and body segments.
Anthropometry
the practice of anthropometry and involves the
collection, analysis and application of anthropometric data
Anthropometrics
The most satisfactory design will be one that is
tailor made for the individual
it is necessary to design for a population of users, called the
target population
Large scale anthropometric surveys to establish data for a particular population are
Very Rare
The simplest sort of measurements and the most commonly available
- defined as a distance measured between two points on the body
static measurements
standard standing posture
free standing, erect at full height
eyes looking straight ahead
relaxed shoulders
arms to the side
as little clothing as possible
Seated person measurements
taken relative to the horizontal and vertical reference planes that represent the seat surface and back of the seat. The point where these two planes and the median plane of the body intersect is called the seat reference point
used for larger distances between points a large ruler
anthropometer
used for dimensions such as breadths, depths and diameters
spreading caliper
used for smaller dimension, like finger lengths
small sliding compass
stature and waist circumference, that
are ____ with each other.
not highly correlated
stature and eye height are ___
highly correlated
Because of the expense and the difficulty of getting people to volunteer to be measured, much of the data available is from
military sources
where the known ratios between dimensions for one population for which data exists can be applied to estimate unknown dimensions for another population
ratio scaling
Criteria of judgement of design features of physical equipment and facilities:
comfort,
work performance
safety
physical effects
equipment is of three kinds
spaces into which men fit, whether for work, rest or protection;
tools or controls which men
use;
and protective clothing and devices
Applications of Anthropometric Data
Equipment and Facilities
Spaces
For seating it is sometimes recommended that ___ are subtracted from sitting dimensions.
40 mm
Shoes would add about __ to __ for men and __to __ for women to height and related dimensions, but it must be remembered that women can wear very high heels sometimes.
20 - 30 mm (men)
40 - 50 mm (women)
Clothing can involve quite large corrections when heavy work clothes or protective clothes are worn as would, for example, be required for work in a cold climate. (true or false)
TRUE
Tests using a mockup are called
fitting trials
a convenient and systematic way to perform fitting trials
method of limits
The vertical distance from the floor to the vertex
As a cross-referencing dimension for comparing populations and estimating data; defines the vertical clearance required in the standing workspace; minimal acceptable height of overhead obstruction such as lintels, roofbeams, light fitting, etc.
stature
Vertical distance from the floor to the inner canthus (corner) of the eye
Applications: Centre of the visual field; reference datum for location of visual display, ‘reach’ dimension for sight lines, defining maximal acceptable height of visual obstructions; optical sighting devices for prolonged use should be adjustable for the range of users.
Eye height
Vertical distance from the floor to the acromion
Applications: The approximate center of rotation of the upper limb and, hence, of use in determining zones of comfortable reach; reference datum for location of fixtures, fittings, controls etc.
Shoulder height
Vertical distance from the floor to the radiale.
Applications: An importance reference datum for the determination of work-surface heights, etc.
Elbow height
Vertical distance from the floor to the greater trochanter
Applications: Center of rotation of the hip joint, hence the functional length of the lower limb.
Hip Height
Vertical distance from the floor to metacarpal III
Applications: Reference level for handgrips; for support (handrails, etc.) approximately 100mm above knuckle height is desirable. Handgrips on portable objects should be at less than knuckle height. Optimal height for exertion of lifting force
Knuckle Height
Vertical distance from the floor to the dactylion
Lowest acceptable level for finger-operated controls
Fingertip height
Vertical distance from the sitting surface to the vertex
Applications: Clearance required between seat and overhead obstacles.
Sitting height
Vertical distance from the sitting surface to the inner canthus (corner) of the eye.
Applications: Centre of the visual field; reference datum for location of visual display, ‘reach’ dimension for sight lines, defining maximal acceptable height of visual obstructions; optical sighting devices for prolonged use should be adjustable for the range of users.
Sitting eye height
Vertical distance from the seat surface to the acromion (i.e. the bony point of the shoulder).
Applications: Approximate center of rotation of the upper limb.
Sitting shoulder height
Vertical distance from the seat surface to the underside of the elbow.
Applications: Height of armrests; importance reference datum for the heights of desk tops, keyboards, etc., with respect to the seat.
Sitting elbow height
Vertical distance from the seat surface to the top of the uncompressed soft tissue of the thigh as its thickest point, generally where it meets the abdomen.
Applications: Clearance required between the seat and the underside of tables or other obstacles.
Thigh thickness (also known as thigh clearance)
Horizontal distance from the back of the uncompressed buttock to the front of
the kneecap.
Applications: Clearance between seat back and obstacles in front of the knee.
Buttock-knee length
Horizontal distance from the back of the uncompressed buttocks to the popliteal angle, at the back of the knee, where the back of the lower legs meet the underside of the thigh.
Applications: Reach dimension, defines maximum acceptable seat depth.
Buttock-popliteal length
Vertical distance from the floor to the upper surface of the knee (usually measured to the quadriceps muscle rather than the kneecap).
Applications: Clearance required beneath the underside of tables, etc.
Knee height
Vertical distance from the floor to the popliteal angle at the underside of the knee where the tendon of the biceps femoris muscle inserts into the lower leg.
Applications: Reach dimension defining the maximum acceptable height of the seat.
Popliteal height
Maximum horizontal breadth across the shoulders, measured to the protrusions of the deltoid muscles.
Applications: Clearance at shoulder level.
Shoulder breadth (bideltoid)
Horizontal distance across the shoulders measured between the acromia
(bony points).
Applications: Lateral separation of the centers of rotation of the upper limb
Shoulder breadth (biacromial)
Maximum horizontal distance across the hips in the sitting position.
Applications: Clearance at seat level; the width of a seat should be not much less than this.
Hip breadth
Maximum horizontal distance from the vertical reference plane to the front of the chest in men or breast in women.
Applications: Clearance between seat backs and obstructions
Chest (bust) depth
Distance from the acromion to underside of the elbow in a standard sitting position.
Shoulder-elbow length
Maximum horizontal distance from the vertical reference plane to the front of the abdomen in the standard sitting position.
Applications: Clearance between seat back and obstructions.
Abdominal depth
Distance from the back of the elbow to the tip of the middle finger in a standard sitting position.
Applications: Forearm reach; used in defining normal working area.
Elbow-fingertip length
Definition: Distance from the acromion to the fingertip with the elbow and wrist
straight (extended).
Upper limb length
Distance from the acromion to the center of an object gripped in the hand, with the elbow and wrist straight.
Applications: Functional length of upper limb; used in defining zone of convenient reach.
Shoulder-grip length
Distance between the glabella (the most anterior point on the forehead between the brow ridges) and the occiput (back of the head) in the midline.
Head length
Maximum breadth of the head above the level of the ears.
Applications: Clearance.
Head breadth
Distance from the crease of the wrist to the tip of the middle finger with the
hand held straight and stiff.
Hand length
Maximum breath across the palm of the hand (at the distal ends of the metacarpal bones).
Applications: Clearance required for hand access, e.g. grips, handles, etc
Hand breadth
Distance, parallel to the long axis of the foot, from the back of the heel to the tip of the longest toe.
Applications: Clearance for foot, design of pedals
Foot length
Maximum horizontal breadth, wherever found, across the foot perpendicular to the long axis.
Applications: Clearance for foot, spacing of pedals, etc
Foot breadth
The maximum horizontal distance between the fingertips when both arms are stretched out sideways.
Applications: Lateral reach.
Span
Distance between the tips of the elbows when both upper limbs are stretched out sideways and the elbows are fully flexed so that the fingertips touch the chest.
Applications: A useful guideline when considering ‘elbow room’ in the workspace
Elbow span
In each case the measurement is made to the center or a cylindrical rod fully grasped in the palm of the hand. In dimensions 34 and 35 the arm is raised vertically above the head and the measurement is made from the floor or seat surface, respectively. In dimension 36 the arm is raised horizontally forward at shoulder level and the measurement is taken from the back of the shoulder blades. In each case these are ‘easy’ reaches made without excessive stretch.
Grip reaches
Nude body weight is measured by a physician scale
Applications: Mostly used in structural support for seats and body restraint system.
Weight
Using a range from the 5th percentile female to 95th percentile male will result in accommodating 95 percent of a 50/50 male/female population, not 90 percent, because of the overlap between male and female body dimensions.
TRUE
The Objective Way to do Skeletal Alignment Evaluations
the objectivity and reliability of caliper and inclinometer measurements
Palpation Meter (PALM)
Will accurately measure six areas to detect scoliosis and provide three measurements to detect abnormal anteropostero curves.
Scoliometer
A complete postural evaluation program for keeping permanent records. Consists of a plastic posture grid, 25” x 48” that can be suspended from ceiling or wall bracket. Includes posture score sheets, suggested
procedures, suspension cord and plumb bob for alignment. The desktop scanner with angle sight (included with kit) can be used for more precise posture appraisals. Comes complete with instruction manual.
Posture Evaluation Kit
has a range of 0 to 60 cm in 0.1 cm increments. Popular uses include measuring shoulder width, long bone length and chest depth for tracking growth and development of children or for use in motion analysis studies.
Large Anthropometer
for measuring wrist, elbow, knee and ankle widths as well as measuring smaller muscle masses like the bicep and calf
Small Anthropometer
Popular uses include measuring maximum chest expansion from resting to full inspiration. Range is from 0 to 24” in 0.50” graduations (0 to 60 cm with 2.0 cm graduations)
Chest Caliper
Measurement for occupational health are always taken on the ___ side
right
Heels of shoes corrections
+25 mm for men and 45 mm for women to all standing or sitting dimensions measured from ground level.
For heavy outdoor clothing
add 40 mm to shoulder breadth and other dimensions concerned with clearance and access.
Measure of relative symmetry. Zero indicates symmetry. The larger its absolute value the more asymmetric the distribution. Positive values indicate a long right tail, and negative values indicate a long left tail.
Skewness
Measure of the relative peakedness of a distribution
Kurtosis
Anthropometry is prone to biological errors for six main reasons:
- Subject posture (very young children) and movement variation
- Instrument application pressure
- Differential tissue thickness
- Diurnal variation
- Location of bony landmarks by palpation
- Accuracy of Equipment (Periodic Calibration)
Human biologists use the term to describe alteration in the measurable characteristics of a population of human being occurring over a period of time
Secular Trend
Longitudinal studies show that at around __ years of age we begin to shrink in stature, that the shrinkage accelerates with age, and that ___ shrink more than ____.
40 yrs old, women shrink more than men
6 thingies Human Diversity
Sex difference
Ethnic difference
growth and development
the secular trend
social class and occupation
ageing
the lumbar protion is curved inward
Lordotic
which results in increased pressure on the discs located between the vertebrae of the spine.
Kyphotic
Most relaxed posture
135 degrees
Sitting in an upright, erect posture (forced lordosis) without a backrest increases disc pressure by ____ compared to standing.
40%
Unsupported sitting in a forward slumped posture increases pressure by ___
90%
How to Reduce Disc Pressure
- Use of a reclined backrest 90° to 100° - 110°
- Use of a lumbar support
- Use of armrests
How to relax muscles without sacrificing the discs
Use of an up to 110° reclined backrest.
How to Reduce Postural fixity
- Periodically stand up, flexing and bending the back and legs.
- Design chair to allow the user to rock and assume a variety of postures.
- A tag that says
Caution: Prolonged sitting may be hazardous to your health
____ increases productivity and reduces complaints of shoulder and back pain.
Adjustability
Adjustable seats should accommodate __th percentile female to __th percentile male
5th - 95th
Adjustable seats minimum range
40.6 - 52 cm based on a compressed seat (loaded with 45.4kg)
recommended seat pan angle
0-10* backward, 5-15* forward tilt
the primary weight of the body can
best be supported by the ___ of the buttocks.
ischial tuberosities (sitting bones)
Seat cushion thickness
4-5cm
For support to the lumbar region only.
Conclude below the level of the shoulder blades to allow maximum freedom of movement for the shoulders and arms. The seat to maximum convexity is about 200mm.
Low Level Backrest
For full shoulder support a backrest height of 550-600mm is required for the 95th %ile man.
Medium Level Backrest
Full support of the head and neck requires a backrest height 1000-1100mm for the 95th %ile man.
High Level Backrest
When seated, adjust the height of the work surface and/or the chair so that the work surface is at ___ height or just below.
elbow
The height of the monitor should be set so that the top of the screen is just ___ eye level.
below
The primary screen should be aligned with your keyboard, mouse and chair.
centrally
try to place monitors to ___ of the light source
to the side
20:20:20 principle
every 20 minutes look 20 meters into the distance for 20 seconds
Tilting the monitor so that the reflections are directed ___ eye level
below
Place document holder where
between the keyboard and monitor
Where to place telephone
The telephone is generally placed on your non-dominant side in a position that does not required excessive twisting or over-reaching to pick up the hand-set.
Static activities, such as holding an object
continuously, ___ the blood and oxygen
supply
reduce
A sufficient oxygen supply is ensured with
___ activities
dynamic
Area A reach zone characterization
Optimum for working with both hands, as both hands can reach this zone and are in the employee’s field of view
For fine motor movements
Possible to handle lighter weights and also enables improved inspection and coordination activities
Pure lower arm movements
Smaller muscle groups are in use
Area for workpiece support, workpiece pallet, or equipment
Area B reach zone characterization
For gross motor movements
Area for tools and parts that are often grabbed with one hand
Upper and lower arm movements without use of the shoulders and rotation of the torso
Area C reach zone characterization
For occasional handling, e.g. of empty containers or transferring parts to the range of movement for the next employee
With shoulder and torso movement
Positioning of all grab containers in areas _ and _
A and B
Heavy parts should be stored within reach in the ___ containers to avoid unnecessary exertion
lower
Bending of the torso below ___mm places a
disproportionate strain on the human body
800mm
Important aspects for planning workstation lighting include:
Avoid strong contrasts
Avoid glare and reflection
