Infant Reflexes/Reactions

cephalocaudal

direction of development “head to tail”

proximal-distal

direction of development “trunk to edge”

infantile reflexes

involuntary, stereotypical movement response to a specific stimulus that is seen only during early infancy

the presence and strength of a reflex is an important sign of ________ system development and function

nervous

primitive reflexes

reflexes that appear during gestation or at birth and become integrated by 6 months of age (some exceptions such as plantar grasp integrating up to 9 months after birth)

if you see _______ reflexes at a later age they are considered pathological, but they are not pathological in newborns as they should be present in all newborns

primitive

righting reactions

reactions (responses) which help the infant learn to keep the head oriented in relation to the body. remains throughout life even though it appears in infancy or childhood

equilibrium reactions

reactions which are automatic responses requiring adaptation by the entire body to restore balance after displacement of the COG (center of gravity) of the body

pathological reflex

an obligatory reflex as a result of a pathological condition which caused damage to the CNS

primitive reflexes are mediated in the _______ and _______

spinal cord; brainstem

righting reactions are mediated in the _______ and lead to ________

midbrain; quadrupedal function (crawling)

equilibrium reactions are mediated in the ______ and lead to _________

cortex; bipedal function (walking)

________ and _______ areas of the brain provide more coordinated complicated reflexes and reactions

midbrain; cortical

_______ level reflex responses exert dominance over ______ level responses

higher; lower (can be seen in the fact that individuals with a spinal cord injury will show equilibrium reactions because those are mediated by the brain cortex which is not injured, while those with a brain injury may not have that high level of reaction)

Level of control: cortex,,, leads to what

equilibrium reactions

Level of control: thalamus and midbrain,,, leads to what

righting reactions

Level of control: pons, medulla, spinal cord,,, leads to what

primitive reflexes

flexor withdrawal

• primitive reflex - spinal cord

• protective, develops balance between flexor and extensor toe

• stimulate sole of foot => dorsiflexion of foot and flexion of hip and knee

crossed extension

• primitive reflex - spinal cord

• develops extensor tone in lower extremities, precursor to creeping and walking

• stimulate sole of foot with extremity fixed => flexion of opposite lower extremity then extension to push examiner away

plantar grasp

• primitive reflex - spinal cord

• place finger at base of toes => toes curl around finger

• integrates at 9 months (just before walking)

galant reflex

• primitive reflex - spinal cord

• unilateral curving of the trunk, provides trunk flexion needed to initiate crawling

• stimulate along the paraspinals => unilateral trunk flexion toward the stimulus

positive support

• primitive reflex - spinal cord

• develops extensor tone

• stimulate feet with firm contact to floor or table => co-contraction of flexors and extensors of the legs

• other wording from internet: elicited when placing weight on the sole of the foot resulting in extension of the legs

rooting reflex

• primitive reflex - brainstem

• survival, aids in finding nourishment, promotes active contraction of neck muscles

• stimulate peri-oral area => turns head toward stimulus with mouth opening

sucking reflex

• primitive reflex - brainstem

• prerequisite for speech and head control, develops oral muscles, tongue placement, swallowing, inhibits gag reflex

• stimulate with finger or nipple in baby’s mouth => sucking

traction reflex

• primitive reflex - brainstem

• to develop tone in upper extremities

• pull child towards sitting position => flexion and adduction at the shoulders, flexion of elbows, wrist, and fingers

• think baby pull up

moro reflex

• primitive - brainstem

• baby in supine position; support baby’s head. allow head to drop back 20 to 30 degrees (in relation to trunk) => abduction and extension of upper extremity followed by flexion and adduction

• look for symmetry of response

spontaneous stepping reflex

• primitive reflex - brainstem

• baby supported vertically around the chest. allow feet to touch support surface. tilt child forward => reciprocal, rhythmical, automatic stepping movement

palmar grasp reflex

• primitive reflex - brainstem

• baby in supine position, head in midline, handsfree. press examiner’s index finger against baby’s palm from ulnar side => baby’s fingers will flex around examiner’s index finger

tonic neck reflexes (list the three types)

ATNR (asymmetric tonic neck reflex), tonic labyrinthine, STNR (symmetric tonic neck reflex)

ATNR (asymmetric tonic neck reflex)

• primitive relfex - brainstem

• supine turn their head. upper extremity on same side will extend and opposite will flex into the “fencing” position

Tonic labyrinthine reflex

• primitive reflex - brainstem

• in prone position with head in midposition, see flexion of extremtiies/increase in flexor tone

• in supine position see extension of extremities or increase in extensor tone

STNR (symmetric tonic neck reflex)

• primitive reflex - brainstem

• sitting/on knees, flexion of the head to chin to chest causes flexed hand and upper extremities and extension of the lower extremities,,, extension of the head causes extension of the upper extremities and flexed lower extremities

• integrates at 8-12 months

true righting reactions

neck on body: once I turn my neck, body will align

body on body: upper body turns, lower body will follow

body on head: once I turn my body, my head will try to alight

basically orient your head with the ground or in line with your body

Labyrinthine

• righting reaction - midbrain/red nucleus

• onset: birth - 2 months and then persists throughout life

• drives child to lift head from prone or supine, babies eyes need to be covered to ensure they are not leading with sight (this part is not shown in the photo)

optical

• righting reaction - occipital cortex

• onset: birth - 2months, persists throughout life

• child will lead with eyes to right head to vertical in response to tilt greater than 45 degrees

Landau

• righting reaction

• inset is 3-5 months w/ peak at 5-6 months

• helps integrate TLR

• extension of head, neck, back, and hips; allows pivot on abdomen

• basically when suspend baby from belly, the baby will extend arms/legs and raise the head

list the 3 equilibrium reactions we went over

protective extension, tilting, postural fixation

equilibrium reactions occur where

in the cortex

protective extension

• equilibrium reaction

• an infant will put hands out to protect from a fall, but can also be done in sitting position by putting arm out sideways or backwards when falling to the side or to the back

tilting reaction

• equilibrium reaction

• response that the body has when placed on a tilt board. if you are sitting on the tilt board and it goes down on the left side, then the body will shift to keep itself upright with lateral flexion of the opposite side

• if you’re standing it’s a similar pattern with extending an arm on the opposite side and flexing the knee or the side that went down

postural fixation

• equilibrium reaction

• allows infants to maintain their position in space when their body is acted on by a displacing force (such as being pushed)

• this is a more advanced reaction so a young infant would not have developed this yet