Postnatal
Growth & Maturation
Growth & Maturation

GROWTH
–

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
Comparison of early and a late maturers
who attain similar height at age 17yrs
EARLY
LATE
Longitudinal vs Crossectional
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 BMIfor-age is unclear
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
ANTHROPOMETRIC
MEASUREMENTS
weight
stretch stature or recumbent
length
segment lengths - upper arm
and lower leg
girths - head, relaxed arm
and calf
skinfolds - triceps,
abdominal and medial calf
MEASUREMENT
EQUIPMENT
wheelchair scale or portable
beam-type balance scale
stadiometer or recumbent
board
modified segmometer
anthropometric metal tape
Slim Guide skinfold caliper
S.H.A.P.E.S. custom software
–
–
serial plotting (up to 100 measurement occasions)
anthropometric profile
Height Distance & Velocity Curves
DISTANCE CURVE


VELOCITY CURVE
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
 Age at PHV
– ♀: 11.4 - 12.2 yrs
 PHV (cm/yr)
– ♀: 7.0 - 9.1 yrs

♂: 10.3 - 12.1 yrs
♂: 13.4 - 14.4 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
–

20-25 times
–

Body, Skeleton, Respiratory System
15-20 times
–

Muscle, Genital Organs
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
14.1
Tibia Width
11.1
13.6
Saskatchewan Longitudinal Growth Study (1964 – 1973)
8
9
10
11
12
13
14
15
16
8
12
16
Table 4-1: Indication(●) of when peak
size velocity of each measurement is
expected to occur in relation to Peak
Height Velocity (PHV)
Before
PHV
●
●
Weight
Sitting Height
Leg Length
●
●
●
Shoulder Width
Elbow Width
Knee Width
●
●
Arm Girth
Thigh Girth
41
After
PHV
●
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
G
G
S
Ga
Ga = G - (3.14xS)
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
Relaxed Arm Girth
Triceps
s.a. Chest girth
Chest
Subscapular
s.a. Thigh girth
Thigh
Front Thigh
Calf
Medial Calf
Maximum Forearm
Forearm
s.a. Arm girth
s.a. Calf girth
s.a. Forearm girth
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
Biacromial/Biiliocristal Breadth
50
Sex
N
Mean
Std.
Deviation
Male
69
1.44
0.12
Female
115
1.31
0.12
2D:4D Ratio
(2nd digit length to 4th digit length ratio)
a
Sex
N
Mean
Std. Deviation
Male
136
0.947
0.029
Female
137
0.965
0.026
Allison A. Bailey, Peter L. Hurda, Department of Psychology, University of Alberta. 2004
2D
51
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
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
Histogram of Both Sexes Combined
Sex
Male
Female
53
N
76
66
Mean
0.975
0.994
S.D.
0.037
0.043
Gradient vs Indicator

Maturity Gradients
–

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
56
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
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.