Infant Terminology and Reflexes

Intro[edit | edit source]

early term 37-38 weeks

late term 41 weeks

post term 42 weeks

affects reaching milestones when they were born

28 weeks-life is viable; very extremely

preterm

Birth weight

irth weight is 2,500 to 4,000 grams or five pounds, eight ounces to eight pounds, 13 ounces. Low birth weight is anywhere from 1501 to 2,500 grams. Very low birth weight is 1000 grams to 1500 grams and extremely low birth weight is an infant that weighs less than 1000 grams at time of birth. Now there are a number of

factors affecting birth weight: Such as ethnicity, the maternal age, maternal health, amount of maternal weight gain in pregnancy, birth order, gestational age, and genetics.

Apgar score[1]:

  1. The Apgar score consists of five components (heart rate, respiratory effort, muscle tone, reflex irritability, and color), each given a value from 0 to 2. Thus, total scores range from 0 to 10, with higher scores indicating a better physical condition. e. The Apgar score provides an accepted and convenient method for reporting the status of the newborn infant immediatelypgar is a quick test performed on a baby at 1 and 5 minutes after birth. after birth
  2. grimace
  3. appearance
  4. respiration


Various ages

  1. gestationsal
  2. chronological
  3. adjusted or corrected age- when they were born vs. when they were supposed to be- use this for milestone for the first two years of life

Primitive Reflexes[edit | edit source]

Primitive reflexes are involuntary motor responses originating in the brainstem present after birth in early child development that facilitate survival. [2]

rimitive reflexes are adaptive reactions in the neonate and diminish as the brain and nervous system mature. Most of these reflexes can be present in normal individuals, even in young adults. [3]

The delay of integrating these reflexes at a typical developmental correlates with delays or deficiencies in reaching milestones and a reduced ability to process sensory information [1,12,15].Persistent reflex activity can influence the quality of a child’s motor skills, especially coordination and balance. They may be linked to learning difficulties and behavioral problems [9,10]. Incomplete integration of primitive reflexes may cause an involuntary motor response in a reflex pattern. The reflex tensions and uncontrolled movements require conscious and increased control over the child’s motor activities. Their activeness prevents the child from moving fluidly. Non-integrated primary reflexes are described in the literature among the factors that contribute to disorders in the harmonious motor development of the child—they are manifested by clumsiness and frequent learning difficulties [4]

Primitive reflexes are stereotypic, automatic, survival-oriented movements (Taylor, Houghton, & Chapman, 2004). The emergence of these brainstem-mediated primitive reflexes often begins in utero, and they then strengthen postnatally; gradually, these integrate during the first three years of life.Functionally, these reflexes allow neonates and infants to interact with their environments through reflexive movements before they are capable of cortically directed actions. However, with ongoing development it is important that children gain volitional control over these reflexive responses, engaging voluntarily in cortically directed, meaningful occupations such as play, self-care, education, and social participation. Failure to integrate these reflexes in the typical developmental stage has been shown to correlate with developmental delays, including interruptions to milestone achievement and decreased ability to process sensory information[5]

[6][5][7]
Reflex Function Initiated Integrated
Palmer stroke palm of hand, grip finger birth-2 months 4-11 months
Plantar stroke sole of foot, toes curl birth 9-12 months
Rooting stimulus provided at cheek or lip and infants turns toward it prenatal 3 months
Sucking root of mouth touched, baby will suck prenatal
Galant strokes along paravetebral line activates trunk flexion toward stimulus prenatal 3 months
Moro when started, will bring arms and legs and neck into extension followed by rapidly bringing arms together birth 2 months
Babinski stroke on foot from heel to toes, big toe moves upward-remaining toes fan out 3-4 months 12-24 months
Parachute arms move forward if they perceive falling 5-9 months persists
Stepping holding baby under arm and feet touch surface, will simulate walking birth 2 months
Flexor Withdrawl noxious stimuli to the foot and the foot withdraws using hip and knee flexion prenatal 1-2 months
Crossed Extension noxious stimuli applied to an extended leg- flexion on that leg and weight shift and extension on contralateral side prenatal 1-2 months
Proprioceptive Placing brush the dorsum of the feet against the edge of a surface; will flex up hip and knee and lift foot up to surface then extend leg to accept weight through their leg prenatal 2 months
Positive support feet on contact surface in a weight-bearing suspension; infant accept weight through bilateral legs; extension of trunk, hip, knees prenatal 1-2 months
Landau prone in air supported- head, hips and back should extend 3-4 months 12-24 months

develop in utero

as nervous system develops, they begin to disappear/integrated

absensce of it or persistance of one could indicate a neurological issue

Tonic reflexes[edit | edit source]

Tonic Reflexes
Asymmetrical tonic neck reflex (ATNR) with lateral rotation of the head, extension of the upper and lower extremity on face side, flexion on skull side birth-2 months 4-6 months motion in utero; promote early visual regard for hand
Tonic labyrinth
Symmetric tonic labyrinth (STNR) flexion of the neck causes flexion of the upper extremities and extension of lower extremities; neck extension elicits the opposite 4-6 months 8-12 months assist with disappearance of flexion posture in prone to allow for quadraped

Righting reactions[edit | edit source]

Neck righting
Optic Righting using vision to maintain head in a vertical position
Labyrinth using inner ear to maintain head in a vertical position when vision is obstructed
Neck Righting when body is titled one way, neck maintains head in vertical position
Vertical Righting when body is titled one way, neck and trunk on opposite side of shift will shorten to maintain vertical position
Rotational righting body on body: flexing either an upper or lower extremity and crossing it over midline to initiate rolling

head on body: as head rotates the body will follow for rolling

Resources[edit | edit source]

Modrell AK, Tadi P. Primitive Reflexes. InStatPearls [Internet] 2021 Mar 21. StatPearls Publishing.

  1. Cnattingius S, Johansson S, Razaz N. Apgar score and risk of neonatal death among preterm infants. New England Journal of Medicine. 2020 Jul 2;383(1):49-57.
  2. Modrell AK, Tadi P. Primitive Reflexes. InStatPearls [Internet] 2021 Mar 21. StatPearls Publishing.
  3. Melillo R, Leisman G, Mualem R, Ornai A, Carmeli E. Persistent Childhood Primitive Reflex Reduction Effects on Cognitive, Sensorimotor, and Academic Performance in ADHD. Frontiers in public health. 2020:684.
  4. Pecuch A, Gieysztor E, Wolańska E, Telenga M, Paprocka-Borowicz M. Primitive reflex activity in relation to motor skills in healthy preschool children. Brain Sciences. 2021 Jul 23;11(8):967.
  5. 5.0 5.1 Hickey J, Feldhacker DR. Primitive reflex retention and attention among preschool children. Journal of Occupational Therapy, Schools, & Early Intervention. 2021 Apr 4:1-3.
  6. Thelen E, Fisher DM, Ridley-Johnson R. The relationship between physical growth and a newborn reflex. Infant behavior and development. 1984 Oct 1;7(4):479-93.
  7. Eskay, K. Infant Terminology and Reflexes. Plus. 2023