Physical Growth, Maturation and Aging

Physical Growth, Maturation and Aging • Growth Measures: Anthropometry • Height • Weight • Segment length • Body breadth • Circumferences

Height • Up to 3 yrs old, measure laying down • 3+ use stadiometer • Cant jump to conclusions: late maturer vs. genetically shorter

Weight • Scales: preferably platform with movable weights • Minimal clothing center of scale • No information on body composition

Body Composition • Fat weight • Lean body weight • Bone • Muscle • Organs • Tissue other than fat

Body Fat • Underwater weighing • Muscle more dense than fat • Completely submerged and expel air • Especially difficult with young children • Potassium 40 • Measure amount in body • Proportional to lean body mass • Lay in body counter, scans and records levels • Expensive and not widely available • Skinfold Thickness • Place caliper over fold of skin at specific sites • Enter measures into equations • Compare to norms

Circumference • Reflect cross sectional size (use non stretchable tape measure) • Standard sites: head, neck waist, hip, thigh, calf, and arm • Chest often inaccurate (inspiration and breast development) • Head: important in young children (just above bony ridge of eyes) • Deviations may imply neurological abnormalities • Used only as a screening measure, not diagnosis

Breadth • Assessing growth, build or physique • Blade anthropometer or breadth caliper • Bone locations e.g.. Shoulders and hips • Can observe proportional changes in physique • Gender differences; men have much larger shoulder to hip ratio

Segment Length • Sitting height: determine contributions of certain segments to total height • Measures from body landmarks • Use anthropometer • Leg length: subtract sitting height from standing height

Maturation Measures • Progress toward maturity by qualitative rather than quantitative advancement • Chronological age: years and days • Maturational levels are much different • Difficult to infer maturity from size (may be small yet mature for age) • Measures of size overlook genetic inheritance or excess fat weight • If genetically tall, may appear to mature early but actually normal maturity

Skeletal Age • Radiographs (x-rays) usually wrist, sometimes long bones or teeth • Compare to standard measures • Increased age: denser and more opaque on x-ray • Greater calcification indicative of advancement • Expensive and unnecessary x-ray exposure

Dental Eruption • Appearance of teeth (only applicable at certain ages) • 6 months to 3yrs, and 6yrs to 13 years

Secondary Sex Characteristics • Pubic hair, genital development (boys) • Pubic hair, breast development (girls) • Rate 1-5 based on standard photos • Also axillary and facial hair • Method limited but good for additional information

Plotting Growth • Distance Curve • Absolute amount of growth • Rate or speed of improvement • Transition points • Velocity Curve • Graph rate of change (amount of increase per year) • Acceleration Graph • Graph rate of change of velocity

The Study of Growth • Careful repeated measurements of body dimensions • Skill development often related to physical size and maturity • Realistically assess capabilities and set realistic expectations

Physical Growth, Maturation and Aging