Infant Physical Development

Chapter 5

Key Questions

What are the key elements of the Harvard Center on the Developing Child framework for children’s health and physical development?

In what ways are the first years of life a period of rapid physical, motor, and perceptual development?

What role does the brain play in the rapid physical, motor, and perceptual development of the first years of life?

What are some important nutrition concerns regarding infants and toddlers?

How do the physical, caregiving, and cultural environments affect development in infants and toddlers?

What are some effects of neuromuscular disabilities on development, and how can early intervention help?

A Framework for Children’s Health and Physical Development

The Harvard Center on the Developing Child Biology of health: the child’s physical makeup Foundations of health: involving the child’s relationships

with others, the immediate environment, and nutrition Caregiver and community capacities: including the time,

commitment, resources, and knowledge available from caregivers and communities

Policy and program: including public health, education, and other polity- and program-level elements in the community

Biology of Health: Physical, Motor, and Perceptual Development

Children grow more within the first 24 months of life than at any other point across the life span. Body weight nearly quadruples. Height doubles. Head circumference increases by 1/3.

New Directions in Infant Motor Research

Principles of Physical Development Cephalocaudal: the direction of physical growth as it proceeds

from “head to tail,” with the greatest growth beginning at the top of the body and moving gradually downward.

Proximodistal: the direction of physical growth as it proceeds from the “near to far,” from the central axis of the body outward to the periphery.

Differentiation: the process whereby physical structures become more specialized over time

Physical growth does not occur in steady increments over time; not all parts of the body grow at the same rate at the same time; growth is asynchronous.

Physical Growth over the First Two Years

The average birth weight for a term infant is 7½ pounds.

Birth weight doubles by 5 months.

Birth weight triples by 1 year.

The average length of a newborn is 20 inches.

Length increases about 30% by 5 months.

Length increases about 50% by 1 year.

Motor Development

Refers to advances in functional motor ability and changes in the quality of motor skills Gross motor skills: motor skills that involve use of the

large muscles of the legs, arms, back, and shoulders, which are used in sitting, walking, running, jumping, and climbing

Fine motor skills: motor skills that involve use of the small muscles of the fingers and hands, for activities such as grasping objects, holding, cutting, drawing, buttoning, and writing

Motor Milestones and Milestone Tables

Motor milestones: motor behaviors that emerge over time and are identified according to the average age at which children develop and demonstrate certain skills or physical attributes

Milestones tables: used to identify developmental delay

Gross Motor Skills

Milestones for large muscle activities Development of posture Learning to walk; locomotion, balance, and practice (crawling to walking)

Development in second yearSkilled and mobile: pull toys, climb stairs

Natural exercise: walk quickly, run stiffly

Milestones in Gross Motor Development

Fine Motor Skills

Finely tuned (coordinated) movements •Perceptual-motor coupling necessary•Finger dexterity (thumb and forefinger)

•Two types of grasps: Palmar and Pincer

•Wrists and hands turn and rotate more

•Experience and exercise have impact

Hearing

Hearing is important especially with regard to development of speech. Infants quickly learn the discrete units of speech sound. By 12 to 13 months, ability to understand specific words increases.

Infants with hearing loss are at risk for delays in speech and language development. Early intervention is important for proper language development.

Vision

Newborns can focus on objects between 10 and 12 inches away.

Visual acuity: the ability to distinguish detail improves from 20/400 at birth to 20/30 by 8 months.

Color vision is comparable to that of an adult by 2 to 3 months of age.

Synaptic Pruning

The elimination of unused neural circuits, which streamlines neural processing and makes the remaining circuits work more quickly and efficiently.

Development of Brain

Early Experience and the Brain

Early experiences affect development Enriched environment makes brain Heavier in weight with thicker layers

Develop more neural connectionsProduces higher neurochemical activity

Impoverished environment Depression is common

Nutritional Needs

Weight and Height grow at phenomenal rate Nutrition needed to promote this 50 calories a day for each pound the infant

weighs More that 2x the amount for an adult

Introduce solid foods at about 6 months (although milk still main source of nutrition) Infant Cereal first because of high iron content Should be continued until at least 18 months

Nutrition and Health

Birth to 6 to months: Breast milk and formula Breast milk is recommended for the first 6 months due

to its high cholesterol and fat content, which is needed to support brain development.

Evidence suggests reduced risk of obesity later in life with breastfeeding as compared to formula feeding.

Between 4 and 6 months, baby cereal mixed with breast milk or formula may be introduced.

Breast Versus Bottle Feeding Breastfeeding is better

Appropriate weight gain, lowers obesity risk

Prevents or reduces allergies and infections

Promotes neurological and cognitive growth

Lowers risk of SIDS and cancers

Better visual acuity and bone density

The only option in poor countries

Bottle Vs Breast Only ½ of mothers breast feed

• Social stigma• Inconvenience• Medical problems

•Medications•Disease

No long-term physical or psychological damage from bottle feeding

American Academy of Pediatrics, Infant Care Manual and Parents Magazine suggest Breast

Six to 12 Months: Solid Food Babies are ready for sold food when their birth

weight has doubled, when they can indicate fullness, and when they show interest in foods others are eating.

Introduce foods one at a time to check for allergies or indigestion.

Strained meats can be added at 8 months.

Offer a variety of healthy foods, and babies will learn to regulate their appetite.

First teeth begin to emerge at around 6 months; soft toast, crackers, and teething biscuits help with discomfort.

Finger foods may be introduced at 8 months at which time babies will “explore” their food. Messiness is to be expected.

Twelve to 36 Months: More Self-Feeding Growth slows. Nutrition should come from meats and other protein

sources, fruits and vegetables, breads and grains, and dairy products.

By 18 months, toddlers can handle a cup. By 24 months, they can feed themselves neatly with

a spoon.

Failure to Thrive

A diagnosis given to children who are consistently underweight or who fail to gain weight as expected.

Classified as: Organic: caused by underlying medical condition or

disease Nonorganic: caused by environmental and

psychosocial factors or a combination of both

Sudden Infant Death Syndrome (SIDS)

Infant stops breathing, usually during night, and dies without apparent cause

• Highest cause of infant death in U.S.

• Highest risk is 4 to 6 weeks of age (according to your book)

• Highest Risk according to most other resources is 2-4 months

• Prone position increases risk

Sudden Infant Death Syndrome (SIDS)

Sudden Infant Death Syndrome (SIDS): the most common cause of postneonatal deaths in developed countries; commonly occurs during sleep while the babies are lying on their stomachs, although the actual mechanism of death is still unknown.

Increased risks if: • Lower birth weight• Siblings with SIDS• Sleep apnea • Lower SES groups• Exposure to cigarette smoke• Placement in soft bedding

Co-Sleeping Many feel that Co-sleeping

Helps breastfeeding Bonding

However, the U.S. Consumer Product Safety Commission (CPSC) warns parents not to place their infants to sleep in adult beds, stating that the practice puts babies at risk of suffocation and strangulation.

And the American Academy of Pediatrics (AAP) agrees.

Any drugs or alcohol consumption makes co-sleeping dangerous

Search for co-sleeping on Google and see what you get

Sleep

Sleep Across the Human Life Span

Safety Issues in Infancy

Accidents are the leading cause of injury and death in children between 1 and 4 years of age.

Baby walkers are responsible for more injuries than any other product designed for them.

Child safety seats lower the risk of death 70% for infants and 55% for toddlers.

Infant and Toddler Child-Care Settings

Should provide indoor and outdoor space for development of gross and fine motor skills

Should provide activities to promote learning

Should meet adequate health and safety requirements

Should be staffed with trained caregivers