1. GROWTH OF THE YOUNG CHILD Mary Rudisill Loraine E. Parish Qi Hang

2.  §9.1 Organismic Constraints Associated with Growth during Childhood  §9.2 Environmental Constraints Associated With Growth During Childhood  §9.3 Task-related Constraints Associated With Growth During Childhood  §9.4Summary

3. §9.1 Organismic Constraints Associated with Growth during Childhood  Organismic constraints, with regard to the topic of growth, involve unique individual characteristics including height and weight.  Weight and height are both measure of health and development.

4. Height  Standing height or stature is the typical method of measurement during childhood.  By the end of the first year of postnatal life, body length increases on average 50 percent from birth height.  After the second year, growth in height slows down dramatically, and from age 2 throughout childhood, growth slowly and steadily increases

5.  Four years after birth the typically developing child’s length doubles and then triples by year 13.  Sitting height is measured as the distance from the surface of the chair to the top of the head when sitting erect.  Sitting height is typically about 65% of total body length during the childhood years and decreases to about 50% when growth is complete in adulthood.

6. Height percentile charts for boys and girls living in 9 cities in China.

7. Weight  In the first six months after birth, weight gain increases rapidly and then begins to slow down.

8. Chinese boys and girls normative weight percentiles from birth to 18 years of age.

9. Body Mass Index (BMI) :  be used to determine the health (i.e., body fatness) of an individual.  BMI is calculated by dividing body weight (kg) by height (m) squared  is known to be related to a number of diseases (i.e., cardiovascular disease, diabetes, hypertension, and a variety of cancers).

10. Changes in Body Proportions  As we grow throughout childhood, various body parts grow at different rates. the head grows at a slower rate than the legs during childhood.  Another important factor with regard to changes in body proportions relates to the sex of the individual.  These changes in body proportions have implications for motor development

11. Head Circumference an important measure when considering body proportions and is an indicator of healthy brain growth. Chest Circumference follow a similar growth pattern to head circumference.

12. BODILY SYSTEMS: CONSTRAINTS ON GROWTH a. skeletal system b. cardiovascular system c. muscular system d. nervous system e. endocrine

13. a. Skeletal System  400+400 ossification centers  Injury to the epiphyseal plate can also impede growth of the bone and can cause permanent damage and cessation of the bone’s growth during childhood.

14. b. Cardiorespiratory System The cardiorespiratory system involves the transportation of oxygenated blood throughout the system Children’s aerobic capacity to exercise for long periods of time is increased as they grow and develop. Girls and boys exhibit similar levels of maximal oxygen uptake during the childhood years

15. c. Muscular System  There are more than 200 muscles that the body uses to move.  Approximately 25% of the body’s weight can be attributed to muscle mass.  During childhood,Muscles grow in diameter and length.

16.  d. Nervous System  The nervous system is comprised of two parts, the central nervous system (CNS) and the peripheral nervous system (PNS).  Abnormal development of the nervous system can impact all aspects of growth and development

17. e. Endocrine System  The endocrine system, controlled by the CNS, is responsible for the emission of hormones, known to regulate growth and maturation.  Growth is regulated by the interaction of genetics, hormones, and external constraints such as nutrition, exercise, and stress.  Three primary hormones influence childhood growth: pituitary growth hormone, thyroid hormones, and insulin.

18. ENVIRONMENTAL CONSTRAINTS ASSOCIATED WITH GROWTH DURING CHILDHOOD  There are a number of environmental constraints with the potential to positively or negatively impact the growth of a young child For example, a well-balanced diet,physical activity, trauma and/or accidents, diseases, and a mother’s prenatal care.

19. Prenatal Care and Childhood Growth  when pregnant women do not engage in safe and healthy prenatal care, the unborn child is at risk of developing conditions that potentially impact childhood growth and development. These conditions include, but are not limited to, birth defects, learning disabilities, delayed social skills, and more commonly, low birth weight (LBW).

20.  Low birth weight (i.e., birth weight ≤ 2500 grams) is a condition among children who do not experience healthy prenatal care (e.g., smoking, poor maternal nutrition, and chronic stress during pregnancy), and therefore, demonstrate growth retardation in the womb.

21. Nutrition and Childhood Growth a. Malnutrition  regardless of the degree of malnutrition, growth is delayed  Malnutrition that occurs during the early years of life has the most detrimental impact on a child’s physical, mental, and motor development.

22. Overweight and Obesity Overweight and obesity are characterized by an increase in the amount of adipose (i.e., fat) stored in the body tissues. Excessive fat stores have a negative impact on the body’s systems.

23.  Physical Activity and Childhood Growth  Engaging in physical activity during the early years of life is important for growth and development. Specifically when children engage in regular physical activity, they build healthy muscles and bones.

24. Genetic and Chromosomal Diseases and Childhood Growth Two childhood diseases, genetic and chromosomal, that impact growth  Achondroplasia, also referred to as Dwarfism, is a genetic disorder that impacts bone growth, most commonly in the arms and legs.  Down syndrome, also known as trisomy-21, is a chromosomal disorder resulting from an additional chromosome 21 attached to the egg or sperm.

25. §9.3TASK-RELATED CONSTRAINTS ASSOCIATED WITH GROWTH DURING CHILDHOOD  Task constraints, with regard to childhood growth, have biomechanical implications for motor performance.  Height, weight, and body proportions influence motor performance throughout the lifespan.  Limb length is another task-related constraint related to motor skill performance during childhood.  Body composition is another task-related factor that is related to motor performance during childhood.

26. §9.4SUMMARY In this chapter, we discussed the importance of childhood growth as a foundation for adult life as well as a measure of healthy development. We explained that there are organismic, environmental, and task-related constraints that influence childhood growth.