Postnatal Growth & Maturation

Growth & Maturation GROWTH MATURATION Increase in size of tissue or organ Hypertrophy Auxetic – increased cell size Accretionary – increased extracellular constituents Hyperplasia Multiplicative – increased cell number MATURATION Change in structure or function of the tissue or organ moving it closer towards the mature state

Methods of Studying Growth Longitudinal Study one or more individuals are monitored over several years time consuming, costly, attrition of sample only way to study the dynamics of growth Cross-Sectional Study sample many different children at same time good for norms and bench marks

Count Philibert de Montbeillard Measured son every 6 months from birth to 18 years (1759-1777)

Standards for Growth Assessment What are the appropriate criteria for choice? Cross-sectional / longitudinal Local / National / International Special populations What is available?

NCHS/CDC Growth Charts The most commonly used norms in North America are cross-sectional norms produced in 1977 by the National Center for Health Statistics. These were recently updated and are now presented by the Center for Disease Control (2000) CDC Growth Charts

Height for Age & Weight for Age

Weight for Height

BMI for Age

Longitudinal vs Crossectional Comparison of early and a late maturers who attain similar height at age 17yrs Longitudinal vs Crossectional EARLY LATE

CDC Growth Charts All Racial and Ethnic Groups Combined Environmental influences appear to contribute to variations in growth more than genetic influences Inadequate sample data for racial- and ethnic-specific charts The effect of race and ethnicity on BMI-for- age is unclear CDC promotes one set of growth charts for all racial and ethnic groups. Racial- and ethnic-specific charts are not recommended because studies support the premise that differences in growth among various racial and ethnic groups are the result of environmental rather than genetic influences. Also, the reference population lacked sufficient numbers of specific racial/ethnic groups to consider separate charts. Although some studies using BMI-for-age to evaluate at risk of overweight and overweight have found differences by ethnic and racial groups, factors that affect differences in growth among racial and ethnic groups, if they truly exist, remain unclear and more research is needed to clarify the issue.

Anthropometric Assessment of Special Populations A Special Population is one that can not be assessed by orthodox methodology Growth & Nutritional Status assessments

Treatment and Rehabilitation of Children with cerebral palsy, brain injuries and other neuromotor problems

S.H.A.P.E.S.

SELECTED MEASUREMENTS & EQUIPMENT

S.H.A.P.E.S. custom software serial plotting (up to 100 measurement occasions) anthropometric profile

Height Distance & Velocity Curves Adolescent growth spurt growth most rapid in first two years

Height Velocity Curves Indicator of maturity Needs longitudinal data Other “systems” have similar curves

Shifting of age axis values to coincident age of PHV before averaging velocity curves

Means of PHV Parameters Age at takeoff ♀: 8.5 - 10.3 yrs ♂: 10.3 - 12.1 yrs Age at PHV ♀: 11.4 - 12.2 yrs ♂: 13.4 - 14.4 yrs PHV (cm/yr) ♀: 7.0 - 9.1 yrs ♂: 8.2 - 10.3 yrs

Intrauterine growth velocity is greater than during any postnatal period. Timing of birth affects growth velocities

Predicting Adult Size Predictions of adult stature can be made from: heights at earlier age parental stature skeletal maturation

Four Curves of Growth

Differential Growth Birth to Maturity 30-40 times Muscle, Genital Organs 20-25 times Body, Skeleton, Respiratory System 15-20 times heart, Liver < 5 times Nervous System

Head Circumference for Age

Shape Changes with Age

Changes in Proportions

Somatotype Sheldon vs Heath-Carter Shape vs Size Mainly used as photographic record of child

Adult Size not well correlated with Birth Size

Differential Growth Adult proportions are a result of complex genetic and environmental influences

Mean Ages (yrs) at Peak Velocity Girls (n=10) Boys (n=12) Leg Length 11.3 13.4 Stature 11.8 14.1 Sitting Height 12.4 14.6 Humerus Width 11.9 Tibia Width 11.1 13.6

Saskatchewan Longitudinal Growth Study (1964 – 1973) 8 9 10 11 12 13 14 15 16

8 12 16

Adult Sexual Dimorphism No difference in proportional weight Male-Female difference greatest in: Triceps, Biceps, Front Thigh and Medial Calf Skinfolds Secondary sexual adiposity

Adult Sexual Dimorphism

Estimates of Muscularity Skinfold-Adjusted Arm Girth – Muscularity Indicator Ga = G - (3.14xS) S G G Ga S = Skinfold Thickness G = Girth Ga = Skinfold adjusted Girth

Girth adjusted for Skinfold at that site s.a. Girth (cm) = Girth (cm) - (Π x Skinfold (mm) / 10) Girth Skinfold s.a. Arm girth Relaxed Arm Girth Triceps s.a. Chest girth Chest Subscapular s.a. Thigh girth Thigh Front Thigh s.a. Calf girth Calf Medial Calf s.a. Forearm girth Maximum Forearm Forearm

Adult Sexual Dimorphism s.a. Girths are Muscularity indicators Greatest differences between the sexes in the upper body Greatest potential for hypertrophy in the upper body Muscularity profile is very sensitive to the specific activity of the individual

Adult Sexual Dimorphism Proportionally larger sitting height in females Males tend to have proportionally longer limbs. Biggest difference in distal segments

Adult Sexual Dimorphism Humerus to Femur Width differences reflects muscularity differences Males have broader and deeper chests proportionally. Classic hip-shoulder dimorphism: Males proportionally wider shoulders Females have proportionally wider hips

Shoulder-Hip Dimorphism   Sex N Mean Std. Deviation Biacromial/Biiliocristal Breadth Male 69 1.44 0.12 Female 115 1.31

(2nd digit length to 4th digit length ratio) 2D:4D Ratio (2nd digit length to 4th digit length ratio) Sex N Mean Std. Deviation Male 136 0.947 0.029 Female 137 0.965 0.026 a Allison A. Bailey, Peter L. Hurda, Department of Psychology, University of Alberta. 2004 2D 4D

2D:4D Ratio Ratio determined in utero Larger ratio in females 2D:4D is negatively correlated with prenatal testosterone and positively correlated with prenatal estrogen Larger ratio in females Married women had higher 2D:4D ratios than unmarried women Significant negative associations were found between 2D:4D in men and reproductive success and significant positive relationships between 2D:4D in women and reproductive success Found to be related to: Aggression, Competitive success, Sexual orientation

Gradient vs Indicator Maturity Gradients Maturity Indicators assessment of the relative rates of development of parts or structures of the body Maturity Indicators Some characteristic of the body that has distinct stages of development that all normally developing children will pass through

Maturity Gradient

Upper Arm Maturity Gradient

Three 13 year old Girls

Three 14 year old Boys

Bigness vs Maturity Do not confuse size with maturation Obesity often associated with advanced maturation skeletally but not in muscular development

Maturity Indicators Age of Peak Height Velocity Skeletal Age Dental Age Menarche Secondary Sexual Characteristics Ratings of Pubic Hair, Penis & Testicular development, Breast development

Skeletal Age

Closer relationship of Age at Menarche with Skeletal Age (SA) than Chronological Age (CA)

Stages of Penis Development

Stages of Pubic Hair Development (Girls)

Synchrony of Pubertal Events

ORCHIDOMETER Word Origin and History for orchid n. 1845, introduced by John Lindley in "School Botanty," from Modern Latin Orchideæ (Linnaeus), the plant's family name, from Latin orchis, a kind of orchid, from Greek orkhis (genitive orkheos) "orchid," literally "testicle," from PIE *orghi-, the standard root for "testicle" (cf. Avestan erezi "testicles," Armenian orjik, Middle Irish uirgge, Irish uirge "testicle," Lithuanian erzilas "stallion"). The plant so called because of the shape of its root. Earlier in English in Latin form, orchis (1560s), and in Middle English it was ballockwort (c.1300; see ballocks ). Marred by extraneous -d- in an attempt to extract the Latin stem. orchid. (n.d.). Online Etymology Dictionary. Retrieved October 07, 2015, from Dictionary.com website: http://dictionary.reference.com/browse/orchid ORCHIDOMETER Source

Synchrony of Pubertal Events

Correlations between several Maturity Indicators PHV = Age at Peak Height Velocity, B2 = Age at attaining Breast Stage 2, PH2 = Age at attaining Pubic Hair Stage 2, M = Age at attaining Menarche, G2 = Age at attaining Gonadal Stage 2

Tanner Breast Stages Tanner I no glandular tissue: areola follows the skin contours of the chest (prepubertal) (typically age 10 and younger) Tanner II breast bud forms, with small area of surrounding glandular tissue; areola begins to widen (10–11.5) Tanner III breast begins to become more elevated, and extends beyond the borders of the areola, which continues to widen but remains in contour with surrounding breast (11.5–13) Tanner IV increased breast size and elevation; areola and papilla form a secondary mound projecting from the contour of the surrounding breast (13–15) Tanner V breast reaches final adult size; areola returns to contour of the surrounding breast, with a projecting central papilla. (15+) Source: https://en.wikipedia.org/wiki/Tanner_scale Prosecution of child pornographers have been based upon the contention that unidentified females with stage 4 nipple development are under the age of 18. However recent studies have concluded that it is not uncommon for females over the age of 18 to have stage 4 breast development.