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Growth and Maturation. What measures would you use to describe growth?. How are body parts different between adults and children?. What is the average height of a 5 yr old? How much taller would this child be in 1 yr? What are expected growth trends for ht & wt during middle & late adulthood?
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What measures would you use to describe growth? • How are body parts different between adults and children?
What is the average height of a 5 yr old? • How much taller would this child be in 1 yr? • What are expected growth trends for ht & wt during middle & late adulthood? • What are the gender differences?
What are effects of exercise on growth? • How do physical characteristics relate to skill performance? • What changes occur in older adulthood?
Physical anthropology- provides information and scientific procedures related to the study of biological growth and development • anthropometry- one of the basic tools used in growth studies. • growth curve- a plot of the pattern of physical change in individuals or groups. • distance curve- plots growth from one year to the next. • velocity curve- reflects the individual’s growth state at any particular moment.
Distance - accum. growth over time • Velocity - increments of change over time Norm reference to determine disease, malnutrition, abuse, delayed maturation
Measuring Length & Stature • Birth - 2 yrs - Recumbent, vertex to sole • 2 yrs+ - Stature • Seated adult (elderly, IWD) - heel to thigh/knee add to equation for M & F
Conception - 0.14mm Birth M - 20 in F - 19.75 in 6 mths M - 26.75 in F - 26 in Yr 1 M - 30 in F - 29.25 in Yr 2 4.75+ in Yr 3-5 2.75+ in Yr 6-adolesc 2.25+ in Adolesc. M - 4 in/yr F - 3 in/yr 17.3 F adult height attained 21.2 M adult height attained 20-30 0.8 in 30-45 Stable 45+ Decrease Growth in length & stature
Concept. - 0.005 mg 19 wk - 14 oz 34 wk - 5.5 lb Birth M - 7.5 lb F - 7 lb 1-3 days - 10%+ 10 days - 7 lb 6 mths - 2/3 oz/day Yr 1 M - 22.5 lb F - 21 lb Yr 2 - 5.5 lb Yr 3-5 - 4.5 lb Yr 6-adol. - 6.5 lb/yr Adolesc. M – 45+ lb F – 35+ lb 18 yr M - 152 lb F - 125 lb 18+ Nutrition, exercise, pregnancy can increase wt. Growth in Body Weight
Combining Body Wt. & Height: Body Mass Index Divide body wt (kg) by height in meters squared • Pounds to kilos - 132/2.2 = 60 kg • Height to meters – 65 x .0254 = 1.65 m • Weight/height squared 60/1.652 = 60/2.72 = 22.1 Relate to BMI chart, p.162-163
5-59 yrs BMI increases for both genders reaching max. velocity around 13-14 • 60-80 yrs regresses • BMI 25-30 kg/m2 indicates health risks
Relationship to MD & Performance • Thin, muscular, small-boned walk earlier • Longer babies walk earlier • Over-weight & obese walk later but catch up • Adolesc. - more body wt. helps in object propelling tasks; less body wt. helps in body propelled tasks; more body wt. negates body support task performance
Adolescence Awkwardness • Primarily in boys • Growth spurts in ht. & wt. Can affect performance in trunk, arm strength, speed, limb movement,
Sitting height vs. stature: • The ratio of sitting height to stature measures the contribution of the legs and trunk to total height. Sitting height is typically 60% to 70% of total body length in the early years and decreases to about 50% when mature height is reached. M - longer trunks before adolesc. F - shorter legs after adolesc. Measure from seat of chair to vertex of head; compare to total stature
Shoulder (biacromial breadth) & hip (bicristal width) changes: • shoulder and hip width appear almost equal in the newborn. In grown adults, shoulder width is typically greater than hip width for all individuals. Ratio constant between 6-11, then decreases for M, stable for F.
Body vs. head: • The head of the newborn accounts for approximately one-fourth of its total height and its legs make up only about three-eighths of its stature - top heavy. In comparison, the adult head accounts for about one-eighth of total height and leg length for approximately half of stature. Males slightly larger Head circumference used to estimate brain growth
Center of Gravity Growth with age changes C of G. Adult - Ratio of C of G to height = 53-59% Child - Higher M slightly higher than F
Physique-(or body build) is a composite of body proportion relationships and body composition characteristics. (Sheldon) • Modified later to include skinfold, circumferences, & wt/ht measures (Heath-Carter) • Somatotype- categorizes an individual’s body build. There are 3 types:
endomorphy- describes a body type that is soft and round in contour, suggestive of a tendency toward fatness and obesity. • mesomorphy- describes a body with well-defined muscularity and balanced body proportions. • ectomorphy- describes the leanest of the body types, with characteristics typically associated with an extremely thin individual.
Changes with aging- changes occur between 3 and 4, then 8, then as individuals reach middle age, mesomorphic characteristics tend to diminish due to loss of muscle mass.
Selected anatomical gender differences • Height & weight - M > • Shoulder width - M >, rotation torque > • Forearm length - M >, lever torque > • Hip shape - F femur insertion oblique > • Leg length - M > • Chest girth - M > • C of G - F lower • Fat free weight - M more muscle, bigger bones
Body Proportions & Motor Performance • Children, top-heavy, high C of G & small base of support affects balance • Weight of objects displace C of G more • Ratio of trunk/leg length + C of G - F can balance better but not gd for running, jumping • Arm length affects throwing, striking force - M adv.
Body types & modifications in sports • Athletes in different sports exhibit different somatotypes and even modify their body type through nutrition, endurance training, and intensive strength and explosive power training
What types would you see with these activities? • Racquet sports? • Aquatic sports? • Gymnastics/Diving/Wt.Lift? • Track & Field & Bicycling? • Soccer, hockey, lacrosse? • Contact field sports? • Court sports? • Baseball, Golf? • Martial Arts? • Dance?
Racquet sports? M-EN • Aquatic sports? EC-M • Gymnastics/Diving/Wt.Lift? M-EC • Track & Field & Bicycling? EN-M-EC • Soccer, hockey, lacrosse? M • Rugby, football? M-EN • Court sports? EC-M • Baseball, Golf M • Martial Arts EN-M • Dance EC-M
Optimal physiques for various sports • Gymnastics – long bodies with short upper & lower limbs (strength, power, rotatory adv.) • Sprint runners – postures accentuates anterior pelvic tilt + muscular buttocks & thighs (extends thigh at optimal angle) • Wt. Lifter – long bodies, short extremities • Contact sports – rounded shoulders, flex. Spine - tuck in on contact • Racquet sports – pigeon toes – speed in short distance
Fetus - Cartilage, membranes ossify in the fetus. Bone deposits from center (shaft/diaphysis) towards the ends. Epiphyseal plates - ossific. Sites after birth • Endochondral bone formation - lengthens - ossification - osteoblasts • Appositional growth - increases diameter, rings on top of each other, inner ones removed – osteoblasts/osteoclasts • Modeling resorption - ends thicken, broken down to keep linear shape
Changes with age- normal aging causes the bones to lose mass more than growth - 35 yrs • osteoporosis- refers to the loss of total bone mass to such an extent that the skeleton is unable to maintain its mechanical integrity. F - after 30 yrs, increases to 2-3% per yr, by 70 yrs 25-30 loss M - 50% less loss Recommendations for peak bone mass -p.174
Exercise & skeletal devl. • Little effect on bone length • More effect on bone density - particularly using wt. bearing activities • Diet - low in Ca and low estrogen decreases rate of deposition • Female-athlete triad - loss of too much body fat - eating disorder - amenorrhea - osteoporosis
Maturity Estimates • chronological age-refers to the age of an individual in relationship to standard calendar days. To estimate level of maturity using this method alone is of limited value because of the wide variance in growth and development. • biological age- generally provides a better method for estimating maturity by providing information that may be compared with the individual’s age. Can be measured by morphological, dental, sexual, or skeletal age.
morphological age- morphology refers to the form or structure of an individual. Morphological age is estimated from height. A measure of height alone is not a good estimate of maturity. • dental age- the age at which teeth erupt may provide information on approximate level of maturity. The deciduous dentition erupts from 6 months to 2 years; permanent teeth generally appear from about 6 to 13 years of age.
sexual age- the biological estimate of sexual age refers to the assessed maturity of primary and secondary sexual qualities - age of menarche, gentitalia maturity • skeletal age- probably the best method of maturity estimate. Is derived from evaluating the successive stages of skeletal growth as seen in radiographs (X rays). L hand & wrist
Maturity Variations: • Diet and other health factors may influence the rate of maturity, but it is the biological clock within the individual that sets the pace of maturation.
Early maturers are those in whom the maturity characteristics are in advance of their chronological age. M=meso F=endo. Taller, heavier, size, strength, speed superior. Baseball - 70% • Late maturers - behind in relation to the standard. Less wt, catch up.
Early maturation related to superior performance with boys. Post pubescent boys initially outperform post pubescent boys - tho’ catch up • Late maturation associated to superior performance with girls
These maturational differences are individual differences, tend to catch up. • secular trend- today’s population is taller and heavier and matures earlier than the population of generations past. This is a secular trend.
body fat growth- body fat layers appear in the fetus between the seventh and eighth prenatal months. Between birth and 6 - 9 months, body fat mass will increase 10 - 20% before tapering off. No matter the age, females have more body fat than males.
Skeletal muscle tissue growth- muscle fibers develop in the premuscular mesodermic tissue. Growth of voluntary muscle during the prenatal period is both hyperplastic and hypertrophic. • hyperplastic continues until shortly after birth, after which cell growth is predominantly achieved by increasing cell size hypertrophy. Type I fibers (slow) - 50-60% at birth Type II (fast) - 25% at birth Transitional - puberty, training?
QUESTIONS • Define growth vs maturation • Describe effects of weight on motor development • What is a good measurement of maturation • Describe the different ‘ratio’ measures of body proportions that are used to indicate growth • How do these ratios differ for males and females? • How do these relate to motor performance for males and females? • Define the three somatotypes • Describe the processes of bone growth • How is bone growth affected by exercise? • How does early vs late maturation affect performance in males and females • Describe differences in height and weight changes for males and females