How can body comp be useful in PT?
- used to assess health related fitness
- patient education
- outcome measure for rehabilitation
Where is essential fat in the body?
- found in bone marrow, liver, heart, kidney, CNS, and breast
- men have 3%, women have 10-12%
- lean body mass is the body weight - body fat weight
What is a good goal for health and fitness for men and women?
- male: 20-29 yo- 16.6% body fat
- women: 20-29yo- 21% body fat
What occurs to body fat with age?
- body fat increases approximately 1%/decade after 30yo
- lean body mass starts to decrease
What is defined as high body fat percentage for men and women?
- >25% for men
- >30% for women
What are the two different body types dealing with obesity?
- android: upper body density- apple shaped (men)
- gynoid: lower body density- pear shaped (women)
Which body type has increased cardiovascular risk?
- leads to excess insulin production and depressed insulin sensitivity
What are some hazards of obesity?
- OA in weight bearing joint
- sleep apnea
- gall bladder disease
- low back pain
- impaired fertility
- shortened lifespan
What is the gold standard for measuring body comp?
- hydrostatic/underwater weighing
- skinfolds then electrical impedence
What is BMI?
- weight (kg)/ height (m2)
- (lbs x 703) / (in2)
What do you need to calculate BMI?
- height--> don't use shoes, but if do take off 1-1.5"
What are advantages of BMI?
- good predictor mortality (death) and morbidity (disease) in general
- all PCP should be measuring this
What are disadvantages of BMI?
- no way to know if heavily muscled or simply over-fat, just an estimate
- insensitive to persons with muscular build
What does waist circumference show?
- high circumference correlated with increased risk for CV disease
- >88 cm (35") for females
- >102 cm (40") for males
- another way to define obesity
What does limb circumference show?
- quick, inexpensive
- good way to monitor girth following training program
- reliable .9-.99
- neck, wrist, hips, thigh, calf, forearm, upper arm
- triceps and calves for kids
- *** not a good predictor of obesity or overweight
What does hydrostatic weighing do?
- body composition can be estimated from a measurement of whole-body density using the ratio of body mass to body volume
- density= mass/volume
- volume= amount of water displaced
- the greater the body density the lower the % of body fat
What are sources of error for hydrostatic weighing?
- subject doesn't exhale completely under water
- air bubbles on skin and hair
- extra gas in GI
- bone density varies among races, decreases with age, and in athletes decreased
For elderly and children what happens with hydrostatic weighing?
- overestimated for chilren (5%) b/c of lower mineral content, less potassium
- elderly have lower density, overestimates
What/how does the bod-pod measure?
- body volume is measured ny changes in pressure in the closed chamber
- better tolerated than underwater
What occurs with bioelectrical impedance?
resistance to electric current will be < in lean tissue vs. fat tissue
What are precautions for bioelectrical impedance?
- always test the same time of day
- alcohol, caffeine, & diuretics should be avoided
- abstain from eating/drinking 4 hours before
- avoid mod/vig activity 12 hours before
- void before
- contraindicated with pacemaker
What are the advantages and disadvantages of skinfolds?
- advantages: practical, inexpensive, and time efficient
- disadvantages: need a lot of practice, difficult to gather fold, hard for obese or extra lean people
What are tricep skin folds usually used for?
don't estimate body fat as much, but instead progress
What are the sites for females for skin folds?
- abdomen (or thigh)
What are the sites for males for skin folds?
What is the procedure for skinfolds?
- always on the right side
- pinch above the caliber
- take 2 measurement and average
- measurements have to be within 2 mm