Anthropometrics/body comp Flashcards
(52 cards)
1
Q
anthropometry
A
- measurement of size, weight, and proportion of the body
- ex. BMI, somatotyping, waist/hip ratios, body typing
2
Q
body composition
A
- focuses on techniques to measure body fat and lean body mass or fat free mass
3
Q
weight bias
A
- the (active or passive) formation of unreasonable judgements based on a person’s weight
- based on looks
4
Q
stigma
A
- the social implication carried by a person who is a victim of prejudice and weight bias
- how someone internalizes judgments
- can occur across the spectrum of stature and weight
5
Q
assessments of potential weight bias
A
- BAOP: belief about obese person’s scale
- ATOPS: attitudes towards obese person’s scale
6
Q
desirable terms to refer to body weight
A
- weight
- excess weight
- BMI
7
Q
undesirable terms to refer to body weight
A
- fatness
- heaviness
- excess fat
- unhealthy BMI
- unhealthy body weight
- large size
- weight problem
8
Q
what should you have to assess people with excess weight ?
A
- private spaces for assessments
- large size gowns and equipment (BP cuffs)
- sturdy armless chairs
- large and XL adult and thigh BP cuffs
- wide base scales that measures greater than 350 pounds
9
Q
sensitivity and privacy
A
- ensure weighing procedures take place in a private location that protects confidentiality
- record weight without judgement or comments
- offer individuals the choice of not seeing results
- if an individual has a BMI greater than 30, do NOT do skin-folds
- is measuring weigh truly necessary ?
10
Q
stadiometer
A
- used to measure height
- measured to the nearest 0.5 cm
- a direct measure , valid and reliable
11
Q
scale
A
- used to measure weight
- measured to the nearest 0.1 kg
- a direct measure , valid and reliable
12
Q
body mass index (BMI)
A
- body mass (kg) / height (m2)
- calculation is age-independent and the same for both sexes.
- reasonable for use in health screening and in large populations
- poor for athletes and active individuals
- reliable due to consistency of height and eight
- validity is questionable because it does not give a measurement of fat mass
- may be useful for categorizing health risks but does NOT indicate current health , need separate assessments .
- nomograms
13
Q
underweight BMI cut-offs
A
less than 18.50
14
Q
normal range BMI cut-offs
A
18.50-24.99
15
Q
overweight BMI cut-offs
A
greater than or equal to 25
16
Q
obese BMI cut-offs
A
greater than or equal to 30
17
Q
waist circumference
A
- risk associated with visceral fat accumulation, where the fat is stored
- different for men and women
- measuring from the top of the iliac crest is standardized
- used by CSEP
- creates a better idea of risk (risk slide on pg.20)
- different ethnic groups have different risks
- men above 102 cm and women above 88 cm
18
Q
BMI interpretation
A
- a simple calculation but a complex variable
- uses height, age, weight
- depends on numerous factors
- nothing about current health
- Edmonton obesity staging system to break obesity into stages + classes
- in general practice you generally will not see obese people
19
Q
obesity in children and z-scores
A
- standardized growth can be calculated to with respect of population needs
- z-scores to indicate how many standard deviations a value is from the mean
- percentiles represent where a values places with respect to the entire distribution
- both are useful for identifying relationships to cohort
- z-score calculators shows child tracking of BMI over time
20
Q
waist - hip ratio
A
- circumference of hips and waist in cm
- accounts for different overall body size
- ratio provides and index of relative fat distribution like how much is carried viscerally
- greater ratio = greater visceral fat in proportion to lower body and increased risk of disease
- men is greater than 0.89 = risk
- women is greater than 0.78 = risk
21
Q
waist - height ratio
A
- stratifies circumference of hips based on height in cm
- value greater than 0.5 is considered increased risk
- formulas can be used to predict % body fat from circumference but is not recommended
- tells us nothing about body fat %
22
Q
circumferences
A
- requires carful measurement of bony landmarks
- have to be consistent
- cannot overlap tape measure or compress body
- have to have a non worn tape measure
- can use head circumference for baby cranial development
23
Q
length and breadths
A
- a test of anthropometry
- used to refine BMI b/c they estimate bone and muscle components of fat-free mass
- segmental lengths are used to predict height in clinical situations
24
Q
seated height
A
- for wheelchaired individuals
- to determine peak height velocity in children (growth spurt)
- client should be seated erect on a bench with legs hanging freely
- may need to adjust posture to ensure erectness
- head and back against wall
- straight ahead, frankfort plane, deep breath
- place set square on head and record height to the nearest 0.5 cm
25
arm (wing) span
- measuring tape placed horizontally from a corner wall / edge
- fingers of one hand at fixed wall edge, and extend arms horizontally
26
peak height velocity (PHV)
- the maximum rate of growth in stature during growth spurt
- determined using charting of height, sitting height and arm span
- used for tracking developmental age of children and allows planning of training of fitness components around growth
- formula to predict "maturity offset"; how long until a child reaches PHV
- age of PHV = age + maturity offset
* slide 35
27
how to measure body comp
1. direct
2. indirect (laboratory bases)
3. double indirect (field based)
28
direct measurements
- chemical or cadaver analysis
29
indirect measurements
- hydrostatic/densitometry
- DEXA
- ultrasound
30
doubly indirect measurements
- skinfolds derivations
- height/weight/circumference derivations
- circumference/breadth
31
body comp 2 compartment models
- divides the body into two components
- assumes fat has a density of 0.900 kg/l
- assumes fat free mass has a density of 1.100 kg/l
- fat vs. fat fee mass or lean body mass is the essential fat is inside like organs/muscles/tissues
- induces error into any technique based on this assumption
32
multiple compartment model
- the greater the number of body compartments accounted for, the greater the reduction of error
- ex. DEXA (3 compartments : fat, bone soft tissue)
33
hydrostatic weighing
- based on Archimedes principle
- any object immersed in fluid is buoyed up by a force equal to the weight of the fluid displaced by the object
- not related to volume displaced
34
what you need to know/do before hydrostatic weighing
- residual volume (air in lungs left over ) based on height, age, and sex
- need to know density of water before weighing
- trapped gas in the gi system (100ml)
- dry body weight, minimal clothing and minimal trapped air
- submerged body weight
35
hydrostatic weighing technique
- minimum equipment required
- body of water, calibrated hanging scale, thermometer, water density table/calculator
- may need weights to assist with submersion
- calculate dry weight
- full end expiration and submersion for 5-10s
- minimize movement
- repeat 5-10 times if needed b/c it is usually not perfect the first time
36
hydrostatic formulas
- predicts body fat % from body density
- can be used to calculate fat mass and lean body mass
- siri, brozek, and lohman equations
- need to select an appropriate equation for the individual and be consistent
- come with a big variability
37
limitations to hydrostatic weighing
- assumption of the constant density of body fat and LBM, 19% error is possible b/c it can be different in women
- assumption of the magnitude of trapped air (GI tract, lungs, body cavity), 8% error in variability in lungs alone
- variability in body mass determination (hydration/dehydration, nutritional status)
- number of trials performed, more accurate with more trials
38
BodPod
- air displacement plethysmography
- same theory as hydrostatic weighing but uses air displacement
- automated
- need to minimize air displacement but not full expiration
- can be used in many populations including children
- validity is 0.94
- test-retest reliability is 0.96
- participant specific equations should be considered
39
DEXA
- dual energy X-ray absorption
- uses a 3 compartment model of lean soft tissue, fat soft tissue, and bone
- uses a "low" type of radiation to scan whole body
- can provide regional data with respect to fat distribution
- inter-day reliability is 0.9-0.99
- concurrent validity with underwater weighing is 0.90
- claims that the error is around 3% for fat
- can use to get segmental bone density
40
DEXA limitations
- expensive
- need technical certification because you are working with radiation
- due to radiation, cannot be used in some populations like pregnant women and kids
- can only accommodate individuals of a certain size
- metallic implants will interfere with measurements
- other radiological tests may interfere with measurements/results
41
MRI
- magnetic resonance imaging
- also uses 3 compartment model
- uses a high frequency magnetic field to vibrate molecules
- can provide very fine spatial (regional) data with respect to fat distribution
- most accurate to determine body comp
- gold standard of indirect measures
42
limitations of MRI
- very expensive
- limited accessibility
- limitations with respect to size of individuals (bore diameter)
43
skinfolds
- measures the thickness of fat-folds including the skin at various sites around the body that can be anatomically landmarked
- can be used as a sum of various sites and can be used in a formula to predict % fat or body density
44
assumptions of skinfolds
- that the choice of sites represent total body fat
- subcutaneous fat is related to total body fat
45
variability of skin folds
- depends on: type of caliper used
- "jaw" tension
- landmarking of site
- amount of skin
- time taken to read measurement
- number of sites or formulas used
- can be a 10% difference between calipers
- spring load of jaw should be 8-10 g/mm2
- need consistency with landmarking of site and amount of fat pinched
- time taken to read measure and finger pressure
- # of sites measured for sum or for predicted of % fat formula
46
equations for predicting body fat
1. sum of skinfolds : predicts % fat, Yuhasz
2. sum of skinfolds to predict body density that can be used in the same formulas as UWW for predicting % fat, Jackson and Pollock
47
validity and reliability of skinfolds
- validity in correlation with hydrostatic is 0.92, is a doubly indirect method that reduces validity
- reliability can be depending on technique and how trained the individual is
- test-retest reliability of r =0.99
48
if factors are controlled in skinfolds ...
- IF all factors are controlled: % fat from skin folds varies around +-5% or higher
- use techniques that involve upper and lower body skinfolds
49
bioelectrical impedance (BIA)
- easy to use, non-invasive, practical, fast
- uses low level electrical current and measures the impedance (opposition to current flow)
- water/electrodes conduct electrical current with less impedance
- tissue that conducts more water will have lower opposition to current flow (muscle, 70% water)
- the greater resistance to current flow the greater the fat content since fat has lower water/ electrolyte content
- may also be used to predict the total body water content (hydration, touching other things)
50
test guidelines and assumptions of BIA
- very strict pre-test guidelines
- no eating or drinking 4 hours before
- no exercise within 12 hours
- must urinate within 30 min
- no alcohol within 48 hours
- no diuretic type medications within 7 days
- no testing at certain days of the menstrual cycle
- validity is QUESTIONABLE
- reliability can be good under controlled conditions 0.66-0.94
51
near-infrared interactance
- measures optical density of "near-infrared light" of two wavelengths for the bicep of the dominant arm
- at the two wavelengths, fat absorbs light and LBM reflects light
- a sensor measures the difference between amount of light emitted and reflected back
- uses formulas that have a variety of assumptions to predict %fat
- underestimation of body fat up to 10% and worse in obese clients
- validity is questionable ; reliability can be good
52
what techniques do you use (considerations)
- consider validity and reliability if technique
- application with respect to performance or health
- practicality or cost
- risk
- time
