Infant Reflexes and Stereotypies

Chapter 10

McGraw-Hill/Irwin © 2012 McGraw-Hill Companies. All Rights Reserved.

Infant

reflexes and

stereotypies

are very

important in

the process of

development

10-2

10-3

Importance of Infant Reflexes

Reflexive movements occur during the last 4 months of prenatal life and the first 4 months after birth

Reflexes occur subcortically (below the level of the higher brain centers)

10-4

Infant vs. Lifespan Reflexes

Most “infant” reflexes do not last beyond the first yearReflexes that endure are called “lifespan” reflexes

Knee-jerk reflexFlexor-withdrawal reflex

10-5

Role of the Reflexes in Survival

Infant reflexes are called primitive reflexes

Asymmetric tonic neck reflexSymmetric tonic neck reflexMoro reflexes

Primitive reflexes are important for

ProtectionNutrition

Sucking reflexRooting reflex

Survival

10-6

Role of Reflexes in Developing Future

MovementPostural reflexes

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

Walking reflex

These reflexes disappear when voluntary behavior surfaces

10-7

Role of Reflexes in Developing Future Movement

Infant Reflex Future Voluntary Movement

Crawling Crawling

Labyrinthine Upright posture

Palmar grasp Grasping

Stepping Walking

10-9

Reflexes as Diagnostic Tools

Can help determine the level of neurological maturationMoro reflex

May signify a cerebral birth injury if lacking or asymmetrical

Asymmetric tonic neck reflex May indicate cerebral palsy or other neurological problem

10-10

Reflexes as Diagnostic Tools

Milani Comparetti Neuromotor Development Examination

Measures several infant reflexes from birth to 24 months

Primitive Reflex ProfileQuantification of the level of presence or strength of primitive reflexes

10-11

Pinpointing the Number of Infant Reflexes

Different terminologies used for same reflex by experts

Rooting reflex = search reflex

Reflexes are often poorly definedPalmar grasp

10-12

Primitive Reflexes ~ Palmar Grasp

The palmar grasp reflex is one of the most noticeable reflexes to emergeEndures through the 4th monthLeads to voluntary reaching and grasping

10-13

Primitive Reflexes ~ Sucking

Occurs pre-and postnatallyStimulated by touching the lips

10-14

Primitive Reflexes ~ Search

Helps the baby locate nourishmentBaby turns head toward the food Contributes to head- and body-righting reflexes

Stimulus ~ touching the cheek

10-15

Primitive Reflexes ~ Moro Reflex

Elicited by the same stimuli that induces the startle reflexMoro reflex precedes the startle reflex and causes the arms and legs to extend immediately rather than flexDisappears at 4-6 months

10-16

Primitive Reflexes ~ Startle

Similar to the Moro reflex May not appear until 2-3 months after Moro disappearsElicited by a rapid change of head position or by striking the surface that supports the babyCauses the arms and legs to flex immediately

10-17

Primitive Reflexes ~ Asymmetric Tonic Neck Reflex

Causes flexion on one side and extension on the otherNot always seen in newbornFacilitates the development of body awareness

10-18

Primitive Reflexes ~ Symmetric Tonic Neck Reflex

Limbs respond symmetricallyIts persistence may impede other motor milestones

10-19

Primitive Reflexes ~ Symmetric Tonic Neck Reflex

Place baby in a sitting position ~ tip forward

Neck flexes

Arms flex

Legs extend

Place baby in a sitting position ~ tip backward

Neck extends

Arms extend

Legs flex

10-20

Primitive Reflexes ~ Plantar Grasp

The toes appear to be graspingStimulus is touching the ball of the footThis reflex must disappear before the baby can stand or walk

10-21

Primitive Reflexes ~ Babinski Reflex

Elicited by a stimulus similar to plantar grasp, but response is differentTest of the pyramidal tract activity for later motor movement

10-22

Primitive Reflexes ~ Palmar Mandibular Reflex

Makes the eyes close, the mouth open, and the head tilt forwardAlso called the Babkin reflexStimulus is pressure to both palms

10-23

Primitive Reflexes ~ PalmarMental Reflex

Elicits a facial response when the base of the palm is scratchedLower jaw opens and closes

10-24

Postural Reflexes ~ Stepping

10-25

Postural Reflexes ~ Crawling

Believed to be essential to the voluntary creeping movementObserved from birth to 3-4 months

10-26

Postural Reflexes ~ Swimming

Characterized by the baby’s swimming-like movements when held in a horizontal position

10-27

Postural Reflexes ~ Head-and-Body Righting

The head “rights” itself with the body when the body is turned to one sidePrecursor to rolling movementsBody righting may not be evident before month 5

10-28

Postural Reflexes ~ Parachuting Reflexes

ProppingRelated to upright postureThis reflex is a conscious attempt to break a potential fall

10-29

Postural Reflexes ~ Labyrinthine

This reflex endures throughout most of the first yearRelated to upright postureHead tilts in the opposite direction of body tilt

Post

ura

l R

eflexes

~ P

ull-

up

R

eflex

When the baby is tipped backward, an arm flexes in an effort to maintain the upright position

10-30

10-31

Stereotypies

Another form of movement observable during infancyCharacterized by patterned, stereotyped, highly intrinsic, and involuntary movements of the bodyBelieved to precede more complex voluntary movements

10-32

Stereotypies

Ester Thalen (1979) studied stereotypies

Stereotypies are intrinsicThey serve no purpose

Thalen grouped stereotypies by body region

Legs and feetHands and armsFingersTorsoHead and face

10-33

Stereotypies

Common stereotypiesSingle leg kickTwo-leg kickAlternate leg kickArm waveArm wave with objectArm banging against a surfaceFinger flexion

10-34

Key Terms