Fetal and Neonatal Motor Behavior

4th week post conception

Closure of neural tube

5-8th week post conception

formation of muscle and skeleton (which is cartilaginous)

5th-6th week

first movements

18th week

first movements felt by mother “quickening”

28th week gestation

a movement repertoire appears

pre-natal movements appearing at 28 wks-40 weeks gestation (term)

Tend to be more general than specific

 Are largely controlled by CNS areas below the cerebral cortex

 Are (or have been) associated with survival, such as rooting reflex, followed by suck-swallow

Reflexes present at 28 weeks gestation

• Rooting

• Suck-swallow

• Moro

• Plantar grasp

• Tonic labyrinthine

• Traction reflex

• Neonatal neck righting

rooting

tactile stimiulis to the side of the mouth; baby turns toward stimulus

• touching their lower lip causes the mouth to open

suck-swallow

response to pressure on the lips and gum; rhythmic suck swallow

moro

abduction of arm followed by crossing the arm across the body

plantar/palmar grasp

pressure across the carpal/metatarsal heads that cue a grasp response

traction reflex

flexion of the arms when stretched

neonatal neck righting

as babies turn their heads, they are able to flip onto their side

tonic labyrinthine

Stimulus is the position of the head (vestibular system of inner ear)

• Response is to pull baby IN to gravity

  • supine- extension

flexor withdrawal and crossed extension

• baby will withdraw limb that is recieiving pain

• other limb will become tonic

newborn

• Flexed in posture

• Gravity dependent

• Asymmetrical

• Primary movement patterns are reflexive

asymmetric tonic neck reflex

babies will look towards stretched/extended arm
Is dependent in movement (has no ability to

translate through space)



Has no ability to change postural set (transfer

from one posture to another)



Has limited anti-gravity control

newborn limitations

• Is dependent in movement (has no ability to translate through space)

• Has no ability to change postural set (transfer from one posture to another)

• Has limited anti-gravity control

integration

means basic circuits remain in nervous system (esp spinal cord) but are “built-upon” with higher level circuitry, i.e., “encephalization” as the nervous system matures.

• will reappear in tines of stress or injury to the nervous system

primitive reflexes in newborns

• Deep attractor wells

• Predictable but NOT obligatory

• Will become integrated

during early infancy (birth to 3)

- Postural tone (resting) in extension increases

- Increasing time in symmetrical postures

- Some increase in anti-gravity control

◦ Decreased head lag in pull to sit

◦ Head stays erect in supported sitting

◦ Prone prop (elbows under body/up on forearms)

righting reactions

designed to provide orientation to gravity and the support surface

allow rotation around the body axis to allow for change in position of space

optical righting

orientation to the visual and postural environment

neck righting (de-rotative)

body de-rotates in correlation with the head/neck

• rotary righting

body on body

body will rotate in alignment along with a body part

body on head

the head will rotate into alignment with the body or the surface to which the body aligns or surface body is lying

labyrinthine

orients position according to head

• anti-gravity

tonic labryinthine

pulls into gravity

segemental; rotary

rolling is _ or _

landau

completey conquered gravity; sustained anti gravity control

• referred to as pivot prone, prone extension

down

extension/gravity travels _ the trunk

symmetric tonic neck reflex

head is extended: UE extension

LE flexion

head is flexed: UE flexion

LE extension

protective extension reaction

happens when body mass is displaced out of your original base of support, creat a new base of support

• downward, forward, backward, sideways

• downward develops first

propped sitting

• righting reactions

• stnr

• protective extension forward

late infancy (7 to 9 months)

• First ability to translate body in space

• Sits erect hands free*

• Progressively sophisticated combinations of movement built on developing postural reactions

• Up against gravity

equilibrium

sideways protective extension

• tries to get back to original base of support

• trunk curves; ABD of upper arm and leg — extension of lower arm and leg

infancy transition (9 to 12 months)

• Increasingly up against gravity

• Mature postural reactions

• All primitive patterns integrated

hitching

baby scooting on bottom

cruising

baby moves alongside furniture or objects

plantigrade

“bear walking”

• especially on grass