Lifespan Physical Development

1. LifespanPhysical Development Feldman: Module 3-1

2. Normal Growth Growth occurs in a cephalocaudal(head to tail) pattern The head takes up one-fourth of total body length at birth, but only one-fifth at age 2. Growth occurs in a proximodistal (near to far) pattern. The head, chest and trunk precede the limbs and extremities.

3. Body Growth in Infancy Average North American newborn weight 7 ½ pounds and is 20 inches long. Birth weight triples in one year and quadruples by the end of two years. By the second year, the child is at 1/5 of its adult weight (30 lbs.) and ½ its adult height (30 + inches). Muscle tissue increases very slowly.

4. Facts about Physical GrowthEarly Childhood Middle Childhood • 2-3 inches per year • 5 pounds per year • Bones harden (skeletal age), lengthen and broaden • ligaments are not yet firmly attached. • Improved strength and muscle tone. • Primary teeth are replaced with permanent teeth • 2-3 inches per year • 5 pounds per year • Baby fat declines • Posture and balance improve due to lower center of gravity.

5. Body Growth and Gender Girls are shorter and lighter and have a higher ratio of body fat to muscle than boys. Children differ in the rate of physical growth. Skeletal age is the best way to estimate the child’s physical maturity. African Americans mature faster than Caucasians and girls mature faster than boys.

6. .Gross motor development involves large muscle groups and activities that generally have to do with locomotion Fine motor development involves smaller muscle groups and activities such as reaching and grasping Motor Development

7. Perspectives on Motor Development • Nature-focused view: • Developmental maturation • Nurture-focused view: • Dynamic systems theory: the child develops new motor skills by adapting and adding to old ones to meet his/her goals

8. Dynamic Systems Theory of Motor Development Mastery of motor skills involves acquiring increasingly complex systems of action. Each new skill is a joint product of: 1) Central nervous system development 2) movement capacities of the body 3) goals of the child 4) environmental supports for the skill

9. Newborn Reflexes blinking Babinski grasping Moro rooting stepping sucking swimming

10. Gross motor development follows a generally universal sequence. Cephalocaudal and proximodistal trends are evident. There is no fixed maturational timetable. Gross Motor Development

11. Age Norms (in Months) for Gross Motor Skills*

12. Iranian orphans are not encouraged to move Indians in Southern Mexico are discouraged from walking Kipsigi parents in Kenya encourage motor skills and children walk early Cultural Variations in Motor Development

13. Gross Motor - Preschool • Age 3 – hop, jump, run for the fun of it • Ages 4 and 5 – more adventurous, climb

14. Using Common Sense • For adequate motor development, preschoolers need places and opportunities to play • There is no evidence that formal lessons facilitate development • Pushing the child may undermine self confidence

15. Gross Motor – School Children • Skipping rope, swimming, bike-riding, skating • 10-11 year olds can learn from sports • Gain greater control over muscles • Boys outperform girls • Need opportunities for physical play

16. Organized Sports in Childhood - Positives • Opportunities for exercise • Learning to compete • Opportunities for peer, friendship relationships • Reduces tendency for obesity

17. Organized Sports in Childhood - Negatives • Negatives • Too much pressure to perform • Physical injuries • Distraction from academic work • Unrealistic expectations as an athlete • Wrong values • Possible exploitation

18. Gross Motor - Adulthood • Gross motor skills improve in adolescence • They peak in the 20’s • They decline through the remainder of adulthood

19. Fine Motor Skills

20. Newborns pre-reach (drops out about 7 weeks) Voluntary reaching appears at about 3 months By 4-6 months an infant can grasp an object in a darkened room. By 7 months they can use one arm Infancy - Sequence of Reaching Behavior

21. Newborn grasping reflex palmar grasp – can be varied 4-5 months, transfer objects from hand to hand 1 year – pincer grasp (Trying to push infants beyond their readiness may backfire.) Sequence of Grasping Behavior

22. Reaching affects cognitive development because it opens up new ways of exploring the environment. Infants use proprioceptive cues to reach as early as 4 months Fine Motor Skills - Infancy

23. Reaching & Grasping in Infancy • Perceptual-motor coupling is used • sense of touch • sense of vision by 8 months • Experience plays a role in development • Pincer grasp goes with crawling & children pick up things from floor.

24. Fine Motor – Early Childhood • Fine motor progress is apparent in • Children’s care of their own bodies • Drawing and painting

25. Self-Help Skills • 2-3 years zips, puts on clothes • 3-4 years button (large buttons) • 5-6 years ties shoes • 2-3 years uses spoon • 3-4 years serves self food • 4-5 years uses fork • 5-6 years uses knife

26. Drawing and Painting • 3-4 years • copies vertical line/circle • Draws a “tadpole” person • 4-5 years • Cuts with scissors • Copies triangle, cross, some letters • 5-6 years • Draws person with 6 parts • Copies some numbers, simple words

27. Fine Motor – Middle Childhood • Increased myelination of CNS • 6-year-olds can hammer, paste, tie shoes, fasten clothes • 7 years – use pencil & print smaller • 8-10 years – write cursive & use hands independently • 12 years – approach adult skill levels • Girls outperform boys

28. Fine Motor – Older Adulthood • Slower motor behavior • Neural noise – irregular neural activity in the CNS • Strategy – may have to slow to perform accurately • Can learn new motor tasks, but more practice required

29. Handedness • Seems to have a genetic influence • Correlates to thumb-sucking before birth & direction of head-turning after birth • Right-handedness is dominant (9:1) in all cultures

30. Handedness • 10% of left-handers process speech in the right hemisphere and 15% across both hemispheres. • Left handers are more likely to have reading problems. • They also have very good visual-spatial skills . • They tend to be intelligent.

31. Influences on Physical Growth & Health • Genetics • Infectious disease • Childhood injuries • Hormones • Emotional well-being • Nutrition

32. Children’s Health - Prevention • Immunization • Meningitis, measles, rubella, mumps, chicken pox, polio • Accidents • Poisonings, falls, drowning, choking • Poverty • Good medical care, nutrition, living conditions

33. Influences on Physical Growth & Health - Immunization • Immunization has caused a dramatic decline in childhood diseases in the industrialized world • 24% of American preschoolers lack essential immunizations (40% in poverty) • Availability of care • Misconceptions (MMR & autism)

34. Influences on Physical Growth & Health – Pituitary Growth Hormones • Growth hormone (GH) needed for development of all body tissues except CNS & genitals • Thyroid-stimulating hormone (TSH) causes the thyroid gland to release thyroxin, needed for normal nerve cell development and for GH to have a full impact on body size

35. Influences on Physical Growth & Health – Emotional Well Being • Psychosocial dwarfism • Caused by extreme emotional deprivation • Appears between 2 & 15 years of age • Can interfere with the production of GH • Very short stature • Immature skeletal age • Severe adjustment problems • Can be treated

36. Adolescence

37. Definition of Adolescence • Transition between childhood and adulthood • Physically begins with puberty • Culturally defined; ends gradually with assumption of adult responsibilities. • Lasts nearly a decade (or more) in the U.S.; culturally exaggerated due to education

38. The Growth Spurt of Puberty • Most rapid growth since infancy • Average of age 9 for girls; 11 for boys • Girls grow 3.5 inches/year; boys 4 inches • 50% of body weight gained in adolescence • Also changes in leg length and facial structure

39. Why Does Puberty Happen Earlier than it Used to? • Nutrition ? – Better than in earlier times • Hormones ? – Found in food supply • Stress ? • Fat ?

40. Stress Theory of Early Puberty • Hypothalamus  pituitary sex glands  produce gonadotrophins • Androgens (testosterone) • Estrogens (estradiol) • Pituitary  thyroid gland  produces growth hormone • Cortisol (stress hormone) may trigger early onset (pituitary activity)

41. Fat Theory of Early Puberty • Weight affects the timing of menarche (106 +/- 3 pounds) • Athletes and anorexics become amenorrheic • Fat and leptin may also be influential

42. Adulthood

43. Normal Physical Development:Early & Middle Adulthood • Early Adulthood, peak muscle tone & joint function • Senescence • Middle Adulthood – gradual changes, lose height, gain weight, in 40s & 50s skin sags, wrinkles, age spots, hair thins, thicker finger- and toenails, yellow teeth

44. Changes in Middle Adulthood (cont’d) • Sarcopenia – age-related loss of muscle mass & strength • Lose 1-2% per year starting at age 50 • Exercise can help to reduce this loss • Also lose bone from the late 30’s; this accelerates in the 50’s

45. Changes in Middle Adulthood • Cholesterol increases • LDL – leads to atherosclerosis • Blood Pressure increases; sharply for women at menopause • Metabolic disorder – hypertension, obesity, insulin resistance, high cholesterol, low HDL, weight gain (Part of normal aging?); weight loss & exercise help • Lungs become less elastic

46. Adult Health - Reproductive System • The 20’s are ideal for reproduction. Risks of miscarriage and chromosomal disorders are reduced. • First births to women in their 30’s have increased in the past two decades • Dramatic rise in fertility problems in the mid-thirties (14 to 26%)

47. Changes in Middle Adulthood - Sexuality • Climacteric – loss of fertility • Menopause – ceasing of menstrual cycles (average age 52) • Drop in estrogen, hot flashes, nausea, fatigue, rapid heartbeat • Gradual decline for men (no andropause)

48. Adult Health Immune System • Capacity declines after age 20, partially due to thymus and inability to produce mature T cells • Stress and depression can also weaken the immune system

49. Adult Health - States of Mind • Western stereotype: deterioration is inevitable • In one study, people with positive self-perceptions of aging live 7 ½ years longer • More optimistic elders are about capacity to cope with physical challenge, better they are at overcoming threats to health • Low SES elders are less likely to believe they can control their health, to seek medical treatment, or to follow doctors’ orders.

50. Biological Theories of Aging • Cellular clock (Hayflick) • 70-80 cell divisions, based on telomeres • 120-year lifespan • Free-radical • Calorie restriction • antioxidants • Mitochondrial • Cellular energy producers • Linked to free radical theory • Hormonal Stress • hypothalamic-pituitary-adrenal axis • Stress & decline in immune function