2 motor development

major motor milestones

newborn - moro, positive support primitive reflexes, flexed posture

two months - head up 45^o in prone

four moths - asymmetrical tonic neck primitive reflex, lifts chest in prone

six months - primitive reflexes gone, pulls to sit, sits tripod

nine months - postural reflexes present, rolls both ways, sits well

12 months - gets to sit, crawls, pulls to stand, walks with one hand help, catches rolling ball

18 months - gets to standing, walks alone, walks up and down stairs with railing

24 months - runs, jumps, kicks, throws ball overhand three feet forward, walks up stairs marking time no railing

36 months - pedals tricycle, walks down stairs marking time, no railing, walks up stairs alternating feet, no railing

48 months - hops, walks down stairs alternating feet, no railing, walks backwards in line

60 months - catches ball, balance on one foot; sit ups, skips

what are reflexes and why are they important incl. examples

involuntary, rapid movements in response to a stimulus

they help an organism to avoid danger eg: withdrawal reflex, blinking reflex and coughing reflex

name six infant reflexes and what they’re in response to

asymmetric tonic reflex - in response to head turn, ‘fencing’ reflex

grasping reflex - in response to palm stroke

stepping reflex - early kicking motion or precursor to walking?

moro response - ‘startle’ reflex to loud sound or sudden movement

rooting - in response to cheek stroke

babinski - in response to the sole of foot stroke

how long should primitive reflexes last

should disappear by 6-8 months, if not their persistence indicates neurological problems

where are primitive reflexes controlled by

the medulla and the midbrain

which two infant reflexes are primitive

moro and babinski

how long should adaptive reflexes last

they should disappear within the first year of life

what does a lack of adaptive reflexes indicate

weak or absent reflexes warn of possible neuronal development problems

what is the purpose of adaptive reflexes and which three infant reflexes are examples of this

sucking, swallowing and rooting all help survival

what are the average heights and weights at the newborn stage, end of year 1 and end of year 2

newborn - 20 inches long, 7 ½ pounds

end of year 1 - 32 inches long (50% greater than birth), triples to 22 pounds

end of year 2 - 36 inches long (75% greater than birth), quadruples to 30 pounds

Berk (2019)

when does a Childs body grow fastest

faster in the first two years than any other time in their life

what is cephalo-caudal measurement

from head to tail, at birth the head takes ip ¼ of total body length, lower body then catches up

what is the proximo-distal measurement

from near to far, from one arm to opposite leg, prenatally, head, chest and trunk grow first then the arms and legs catch up

what type of pattern did Gesell and Ames (1940) suggest motor development follows

cephalon-caudal pattern, for head control, reaching, sitting and walking

what did Slater and Brenner (pp 47) say development is controlled by

“development is controlled by a maturational timetable… each animal species has its own sequence, and experience has little, if any, effect on motor development”

what are three gross motor milestones

posture - supine (pull up to sitting) and ventral suspension/prone

standing and walking

age of acquisition is variable; pattern is more meaningful

what are the developmental milestones in relation to sitting

newborn: complete head lag

3months: slight head lag

4-5 months: no head lag

5-6month: sits supporting self

6-7months: sits without support

10-11months: good support while sitting and able to perform movement

12+months: sits in a chair

what are the developmental milestones in relation to ventral suspension

newborn: lack of head control

6 weeks: momentarily holds head in same place as rest of body

8 weeks: maintains head in line with body

3months: maintains head above line of body, holds chin and shoulders off surface

5-6months: keeps the chest and shoulders off surface, maintains weight with hands and elbows

what are the developmental milestones in relation to the prone position (extension of ventral position)

at 3 months can roll from prone to supine

at 8-9 months crawls - required hip and leg muscle control, can lift trunk off floor

what are the developmental milestones in relation to standing and walking

2 months: hold head momentarily

6 months: can bear almost all weight, using legs

9 months: stands holding furniture, can pull self ip to standing

12 months: walks with broad case, steps unequal in length and direction

15 months: crawling up steps, standing position without help

2 years: picks up objects off the floor without falling, walks backwards

3 years: up and down steps one foot per step

what are the two sources of variability

intrinsic and extrinsic

what is meant by an intrinsic source of variability

genetically determined attributes eg. physical characteristics, temperament

what is meant by an extrinsic source of variability

environment, socioeconomic status, family, culture

is motor development sequence genetically determined

simply because of the general tendency for motor development does not mean it is genetically determined

major milestones in fine motor skills

newborn - root, suck primitive reflexes; orients to sound; smiles to voice; variable cries

two months - gurgles

four months - coos

six months - looks toward person talking; vocalises to answer; laughs

nine months - transfers; radial-digital grasp; touches cheerio with finger; raking pioneer grasp

12 months - pincer grasp; voluntary cube release into cup; holds bottle

18 months - inserts shapes, stacks two to three cubes; scribbles (fisted); self-feeds (fingers)

24 months - copies vertical line; stacks six cubes; uses spoon; helps dress

36 months - copies horizontal line; circle; stacks 10 cubes; uses spoon well and fork, drinks from open cub, removes socks and shoes, undresses

48 months - copies cross, draws two to four part person; cuts paper in half; dresses no buttons

60 months - copies square, draws 10 part person, colours between lines, tripod pencil grasp; washes and dries hands thoroughly

what are examples of fine motor skills

-precise movements of hands and fingers eg. pincer grasp

-eye hand coordination

-manipulating small objects

what are fine motor skills interlinked with (Gerber et al., 2010)

visuospatial skills which are both motor and cognitive skills

what are the developmental milestones in relation to grasping

newborn: grasping reflex

3-4 months: ulnar grasp (no thumb)

5 months: grasp objects voluntarily

4-6 months: adapt ulnar grasp for shape and size

1 year: pincer grasp

what did Rocha et al. (2013) find regarding reaching and grasping

infants tested longitudinal at 4,5,6 months

balls were large, small, soft or rigid

from 4 months infants adjusted their reach and grasp to suit the size and texture of the object

what are the developmental milestones in relation to grasping

newborn: pre reaching

3-4 months: purposeful reaching

4-5 months: transfer between object hands

5-6 months: continue to reach for an object in the dark

what did Witherington (2005) find regarding reaching and grasping

infants tested longitudinally at ages 5,6,7 months

object presented either horizontally or vertically

infants of all ages adjusted the orientation of their hand when reaching towards the object

what did McCarty and Ashmead (1999) find regarding reaching and grasping

tested 5,7,9 month infants in a dark room

reaching for a rod that had lights inside

on half the trials the object remained visible, on the other half of the trials the light inside the object were turned off after the infant began reaching

infants still reached for the object even though it was no longer visible

what did galloway and thelen (2004) research into whether motor development follows a cephalo-caudal pattern

tested 8-15 week olds, weekly

held a toy at midline between shoulders and midline of hips

timing of reaching with hands and feet

-hands 15.7 weeks (extended contact 16 weeks)

-feet 11.7 weeks (extended contact 11.8 weeks)

how does teratogen exposure affect motor development

alcohol consumption damages the developing motor control system (Barr et al., 1990)

pregnant woman reported teratogen exposure, gross motor and fine motor control was examined later when their children were 4 years old and there was a significant negative effect of alcohol consumption on fine and gross motor skills

this risk seems to occur throughout pregnancy (Doney et al., 2014)

how are actions developed from skills

standing, walking, pincer grasp are building blocks of more complex sequences, actions

separate abilities blend together, become more complex, more effective

what is thelen and Spencer (1998) dynamic systems theory

motor developments result from ongoing and dynamic interaction between:

-developments of the nervous system

-capabilities of the body

-environmental constraints and support

critical idea is that these all interact to allow the development of the optimal movement for a particular situation

self organisation within the system

how did thelen (1999) investigate the dynamic systems theory

3 month olds tested

free condition - ribbon attached to one leg, made an overheard mobile move, infants quickly learned to kick legs independently to move the toy

yoked condition - both legs yoked together, infants learned to kick both legs together to move the toy

natural kicking pattern adapted to achieve their goal