Motor Development Exam 2

Universality

development patterns common for all humans

Variability

individual variation in development

Embryonic Development

Limbs form at 4 weeks, human form noticeable at 8 weeks

Fetal Development

8 weeks-birth

Cephalocaudal

head to toe

Proximodistal

midline to extremities

Plasticity

capability of cells to take on a new function

Placenta

Organ develops in mother’s uterus during pregnancy

Placenta Roles

provides oxygen, nutrients, removes waste, prevents mixing of blood

Dominant disorders

defective gene from one parent. Ex: Huntington disease

Recessive disorder

defective gene from each parent. Ex: cystic fibrosis

Distance curves

show extent of growth

Velocity curves

show rate of growth

Peaks on velocity curves

show ages at which rate growth change

Females

spur begins at 9, height tapers off around 14-16, peak heigh occurs around 12

Males

growth spurts at 11, height tapers off around 17-18, peak heigh around 14

Teratogen

any drug or chemical that causes abnormal development in a fetus

Differentiation

process wherein cells become specialized, forming specific tissues and organs

Hyperplasia

an increase in the absolute number of cells

Ossification

begins at primary centers in the mid portions of long bones at 2 months

appositional growth

increase in bone girth

Secondary centers

growth in bone length occurs here at the end of bones

Secondary center examples

epiphyseal plates, growth plates, pressure epiphyses

Traction epiphyses

muscle tendons attach to bones

Osgood-Schlatter Disease

painful lump below kneecap: treatment is to refrain from activity

Cessation of bone growth for girls

occur at 16

Cessation of bone growth for boys

occur at 18

Osteoporosis

leads to rib cage collapse, stooped posture, reduced height

Hypertrophy

Increase in muscle cell size

Age 50

Individuals lose muscle mass

By 80

average 30% of muscle mass is lost

Growth hormone

secreted by anterior pituitary, necessary for normal growth

Thyroid hormone

secreted by thyroid gland,

Types of TH

thyroxine (T4), Triiodothyronine (T3)

Gonadal hormones

influence on growth, sexual maturation

androgens

secreted by testes, adrenal glands, promote growth of muscle mass

estrogen

secreted by ovaries, adrenal cortex, promotes accumulation of fat

Insulin

vital for carbohydrate metabolism, necessary for full functioning of growth hormone

decrease, increase

in young adults, the proportion of lean body weight making up body composition often begin to as a result of in fat weight

56%

muscle mass increase rapidly in boys up to age 17 and ultimately accounts for __ of mens body weight

Primary ossification centers

refers to the area in the mid portion of the shafts of long bones where bone cells are formed so that cartilage-model bones of the fetal skeleton begin ossifying, from the center outward, to form bone shafts

Endocrine system

exerts its control over specific cellular functions through chemical substances called hormones

Spontaneous movements

not caused by known external stimuli

Spontaneous examples

squirm, thrusting legs/arms, stretching fingers/toes

Reflexive

stereotypical responses elected by specific external stimuli

Reflexive examples

palmar grasp reflex, sucking reflex

Original theory

extraneous, no purpose

Current theory

building blocks, similar to some voluntary movements

Moro reflex

Prenatal- 3 months, may signify cerebral birth injury

Asymmetric tonic neck reflex

Prenatal- 4 months, may indicate cerebral palsy

Babinski reflex

birth to 4 months, presence after 2 yrs of age indicate upper motor neuron lesion

Infantile reflex

do not last beyond the first year

Lifespan reflex

can be used to assess neurological function

Primitive reflex

nutrition, survival, protection

Postural reactions

help maintain posture in a changing environment

Locomotor reflexes

provide automatic movement that is “practice” for future voluntary movement

Sucking reflex

occurs pre/post-natally, stimulated by touching lips, 3 months of infancy then voluntary

Primitive reflex

Palmar Mandibular Reflex

eyes close, mouth open, head tilt forward. disappears at 3 months

Primitive Reflex

Stepping

Locomotor: birth-5 months.
Resembles crude form of walking

Reflexive movements

involuntary movements that an individual makes in response to specific stimuli

Applied explanation

Reflexes serve as the basic of human movement that leads to voluntary movements

Integrating sensory information

motor development and early movement experiences

Moving room

paradigm has been used to study the development of postural control and balance of infants

Norm-referenced scales

indicate where a person falls within a group of similar individuals matched by factors such as age, sex, race

Locomotion

Moving on one, two, or four limbs. Complex task involving many interacting systems and constraints

Crawling

moving on hands and abdomen

Creeping

moving on hands and knees

Walking

first form of upright, bipedal locomotion

50% phasing of legs

Proficient Walking

Increase: stride length

Decrease: base of support

Pelvis: rotates

Arms/legs: oppositional movement

Double knee lock pattern

Later walking

Increase: out-toeing

Decrease: stride length, pelvic rotation, speed

Running

occurs 6-7 months after walking

50% of phasing of legs

flight phase followed by single support

Early running

Arms: high guard

Base of support: wide

Range of motion: limited

Stride length: short

pelvic rotation: very little

Proficient Running

Stride length: increase

Base of support: decrease

pelvis: rotates

arms/ legs: oppositional

planar movements: (ap direction

Trunk leans slightly forward

Rate controllers of running

balance and strength

Jump

propel off ground: one or two feet

Landing: on two feet

Hop

Propel off ground: one foot

Landing: same foot

Leap

Propel off ground: one foot

Landing: opposite foot

asymmetrical

galloping is an example of locomotor skill that requires

Jumping limiter

ability to develop enough force to bring the body into the air from a still position

Treadmill

Type of training is associated with an earlier onset of walking for infants with down syndrome