Growth & Development of Systems Contributing to Functional Movement

What system is most frequently used as an indicator of physical growth and development?

Skeletal

The summation of what affects growth of the skeletal system?

Heredity, hormones, nutrition, environment, general health, and stresses

Formation of osseous tissue

Length and width

Radiographs establish a physical maturity

Ossify by 25 years

Importance of height charts

See if child is within normative values

(physical growth and overall growth are related)

Infant proprtions

Large head, long trunk, short extremities

Body proportions with growth

Head is relationally smaller, pelvis narrows, shoulders are broader, and extremities grow in length

(know general trends!)

What is an ossification center?

Area where cartilage is replaced with bone

(where growth occurs)

Primary ossification centers

Center of bone shaft (diaphysis)

Growth starts here, ossifies here first

Secondary ossification centers

End of bone (epiphysis)

What is the growth plate?

The space between the primary and secondary growth centers (epiphyseal plate)

Where growth occurs!

Bones in infancy in childhood

Long bones are well ossified by birth

Period of rapid bone growth (contributes to responsiveness to orthopedic intervention -- structural changes can occur)

Forces have great impact on formation & structure of bone

Skeleton undergoes tremendous transformation

What promotes skeletal system development?

Movement

Bones in adolescence

Bone continues to grow and remodel according to mechanical loading

Rapid growth in length and width of bone may result in decreased flexibility & athletic injury

Stress fxs in the athlete's increase

Epiphysis is very susceptible to injury

Apophyseal avulsion = more frequent (e.g. Osgood-Schlatter's)

Cartilage injury is common

Important to maintain proper conditioning for athletic activities at this age - warm up and cool down (cross training is important !)

What stresses affect bone growth?

Tension, compression, torsional forces

Density of growing bones

Less dense (softer) / more porous (flexible)

bones are not fully ossified

Greenstick fx

Bends and cracks instead of breaking

Periosteum in growing bones

Thicker, harder to detect fx

Do growing bones remodel better after fxs?

Yes

Things to look out for in growing bones

Growth plate injury and infection

Apophyseal avulsion

Other influences on bone growth

Muscle usage (m. pull provides stresses on b.)

Mineral content inc w/ usage (promote physical activity)

Congenital conditions

Injury

Protecting the growth plate is imperative !!

What increases before strength?

Muscle mass

How does ratio of muscle mass to body weight change with growth?

Greatly increases

When does muscle mass greatly increase?

Btwn 5-18 yo (until skeletal maturity)

When is peak muscle growth in males?

The same time as peak bone growth in adolescence

Doubles 11-17 yo

How does muscle mass increase after the conclusion of growth?

Physical exercise, metabolism, nutrition, age, sex

Infancy & preschool muscle

Gradual inc in strength

Infants have more fast-twitch fibers (jerky mvmts)

Endurance increases (still limited)

Must be provided with a safe and stimulating environment to move and explore

Early motor competence and confidence to the enjoyment of physical activity throughout childhood and beyond

Childhood / Preadolescence muscle

Linear increase in strength and endurance

LEARN THROUGH MOVEMENT

Exercise and play in childhood/preadolescence muscle growth

Engage in rough-and-tumble play - control "when to stop"

Organized sports can develop teamwork and physical fitness

School-age children need daily physical activity

Promote a healthy body composition and bone mass

Academic achievement has been linked to vigorous physical activity in children

Adolescent muscle

Strength and endurance spurt in boys

(likely girls too, research was only done on boys)

Physical activity guidelines for adolescents

60 minutes or more a day

At least 3 days/wk should include vigorous exercise

Warm-up & cool-down sessions

Strength training can inc m. & b. mass

Male vs. Female strength

Inc at the beginning of adolescent age (higher in males d/t growth spurt, testosterone, etc.)

Which organ is nearest it's adult size at birth?

Brain

Brain percentages of adult weight

25% at birth

50% at 6 mo

75% at 3 yrs

90% at 5 yrs

How does the skull grow?

Fontanelles accommodate for bone growth

Growth slows after 2 years

Myelination

PNS is nearly complete at birth (allows access to information from the environment)

Very rapid in the first two years - CNS organization

When is myelination complete?

Nearly complete at 10 years

Continues until 30 years or possibly longer

When does myelination of the CNS & Tracts occur?

CNs (and motor & sensory fibers) - Fetal months

Tracts - First year / years

What does brain growth appear to coincide with?

Stages of cognitive development

When do motor skills become more automatic?

As the NS begins to inc speed of conduction (6-10 years)

Adolescence skills

Improve with practice - refinement of skills

How does heart rate change from birth to adolescence?

Slows gradually

Normal resting HR newborns

70-190 bpm

Normal resting HR children 10 & older

60-100 bpm

How do heart size and blood volume increase throughout childhood?

Increase and reach full size/amt when they stop growing

What is heart size closely related to?

Physical growth (ht, wt, BMI, body surface area)

Systolic BP change w/ growth

40-50 mmHg in infants -> 100 mmHg in adolescence

What is an important factor in determining a child's cardiac parameters?

Lean body mass

Overweight & obese children may show cardiac adaptations as early as age 2

Lung changes w/ age

Alveoli development (only a small amt at birth)

Inc in size & lung capacity w/ age (in relation to body size)

Ribcage in infancy

Highly compliant - paradoxical breathing (somewhat normal, red flag is consistent)

Paradoxical breathing

Chest in & abdomen out when breathing in

How does respiration change w/ age?

Stabilizes

Diaphragmatic breathing from 0-4 years

Thoracic breathing pattern from 5-7 years

How does respiration rate change with age?

Rate slows down

40-60 breaths/min in infancy -> 17 breaths/min in adult

How does motor development impact respiration?

M. development of head and upper body inc lung expansion

What improves the diaphragmatic angle for more efficient diaphragmatic and intercostal breathing?

Independent upright position

What assists in stabilizing the ribs for more efficient diaphragmatic breathing?

Abdominal control

What challenges the CV system and promotes development?

Increased motor activity

(stress your systems to make them grow)

Childhood & adolescence somatic senses

Haptic perception improves

Two-point discrimination (~7 yo)

Praxis (motor planning)

Childhood & adolescence vestibular

Earliest system to respond

Righting rxns have basis in vestibular input

Very strong self seeking stimulation in preschool (love spinning, etc.)

Stabilization of system by prepubescence

Childhood & adolescence proprioception

Used in combination w/ tactile & vestibular systems as newborns

May be used for reach prior to development of visual perception (5 mo)

Controlling balance in upright, requires vestibular, proprioceptive & visual information

Vision in infancy

Visual acuity is poor at birth but steadily improves

Do not recognize colors at first, only shading

Depth perception and binocular vision develop as the infant controls midline & establishes head control

Visual tracking (infancy)

Begins at 2 months

Improves w/ head control

Visual changes in childhood & adolescence

Many perceptual tasks occur during childhood related to cognition & learning

SIze constancy

Figure-ground perception

Visual closure

(all three complete by puberty)

Childhood vision problems

Amblyopia (drifting eye)

Strabismus (crossing of eyes)

Adipose tissue growth pattern

Steady inc for first 8 years

Slows as skeleton growth inc

May have negative growth in boys at puberty

Adipose tissue fat cells

Inc in number throughout growth

Obesity places child at risk of early onset - T2DM, high BP, joint pain, high cholesterol, breathing problems

Preschool growth trends

Steady growth of skeleton & m. (slower than infancy)

Chunky physique of infant becomes elongated

By what age are the extremities 60-70% longer than birth?

2 years

How does motor development precede in preschool age?

Large before small (gross motor before fine motor)

School age growth trends

Steady growth (somewhat less than preschool)

Limbs growing faster than trunk = changing body proportions

Muscle mass increasing (same for both sexes)

How does COG move during school age?

Caudally

Adolescent growth trends

Growth spurt for skeleton, m. & viscera

Wide range of variation

Maturing reproductive system (puberty)

When do girls achieve adult stature?

17-18 yo

When do boys achieve adult stature?

18-21 yo

Preschool - childhood cognitive/social development

Concrete thinkers

Understand rules

Hands-on learning is most effective

Social cognition - peer relationships (friendships!)

Pattern of thought and reasoning

Mnemonic techniques

Feelings of success encourage the child to continue making efforts (praise)

Teaching the preschooler/child

Attention span is limited to a max of 45 minutes

Present information in a truthful, factual, age-appropriate manner

Periods of praise & occasional rewards reinforce learning accomplishments

Peer attitudes can influence learning & enhance the application of values taught

Teaching the adolescent

Concrete phase of thinking

May try to manipulate rules, engage in risky behaviors, deny own mortality

Teen violence

Privacy

Development of responsibility

Give opportunity to develop independence & responsibility!

Teaching the adolescent pt 2

Major task of adolescence is achieving a stable-self identity

Cultural considerations

Role confusion

Family should offer support and guidance

Social skills & cognitive reasoning

Peer relationships

Teaching the teen

Developing a trusting relationship is the first step

Communication must be supportive and not threatening to sense of independence/autonomy

Provide opportunities for independence & responsibility

Still learning (7)

You've started learning these terms. Keep it up!