REFLEXES

A reflex is a voluntary action in which the body responds without thinking about it. Often when we think of reflexes we think of the doctor hitting your knee with a hammer. Reflexes are used to assess and determine the health and development of a baby’s nervous system.

Many infant reflexes will diminish over time, and are considered abnormal if they persist past a certain age. Your pediatrician will perform a physical exam to determine if the reflexes are typical of normal development.

Asymmetrical Tonic Neck Reflex (ATNR) “aka” The Fencer Reflex”: This reflex is can be elicited with the baby lying on his back. Adjust the head to one side and the reflex will cause the arm and leg on the same side to straighten, while the opposite arm and leg will flex. This is a transitional reflex that prepares the infant to roll over. It attributes to the development of  hand-eye coordination along with activities that require crossing the mid-line of the body. This reflex typically is integrated by 4-6 months.

Functional significance: Social/learning problems can be associated with this un-integrated reflex such as poor hand eye coordination due to difficulty with ocular tracking that require crossing the mid-line. This affects handwriting and written expression.

Babinski Reflex “aka” The Big Toe Sign: This occurs after the sole of the foot has been firmly stroked. The big toe then moves upward or toward the top surface of the foot. The other toes fan out. This is due to the lack of maturity of the infants neurological system. This is a normal reflex and may disappear as early as 6 months and as late as 2 years.  

Functional significance: A Babinski reflex in an older child or adult is atypical and is a sign of a problem in the brain or spinal cord. A Babinsiki reflex  can present on one side but not the other is also atypical, and can indicate which  side of the brain is involved.   

Corneal/Eye Blink Reflex: This reflex is involuntary blinking of the eyes caused by a tactile stimulation or bright light to the cornea. This protection mechanism helps keep the eye from drying out when irritated by dust, smoke, allergens or other foreign object.

Functional significance: Excessive eye blinking may be caused by conditions such as blepharospasm (involuntary tight closure of the eyelids), a rapid, involuntary muscle contraction.

Gag Reflex: This is triggered with touch to the posterior tongue, soft palate, or tonsillar area. With infants, this can be triggered when a baby attempts to swallow too much milk. Occasionally a baby will gag on excess mucous in the back of their throats, particularly in the first few days after birth. This can make them momentarily look distressed and turn blue.

Supporting the baby in an upright position or placing them over your shoulder will help relieve the distress. This reflex will diminish around 6-7 months in babies allowing the baby to swallow chunky or swallowed foods. In children and adults this reflex is usually triggered only by the presence of an large object in the back of the throat.

Functional significance: While the gag reflex has no relationship to swallowing in adults, it is important in infancy to prevent choking as the infant transitions from liquid to solid foods. The gag reflex does not disappear and persists throughout your child’s life. For those with a Hypersensitive gag reflex (HGR), the reflex continues to be activated by substances in the mouth. Typically food that are sticky such as bananas and mashed potatoes, get stuck. In extreme cases this can lead to a picky eater or malnourishment.

Landau Reflex “aka” The Superman Response: The onset of this reflex is typically about 3-4 months. When the child is placed in the prone position and supported in the air, the head will extend and the back and hips will expend in sequence. This reflex will typically be integrated about 12-24 months.

Functional significance: This reflex breaks up the total flexion pattern seen at birth. If the landau reflex fails to diminish, children may experience short-term memory problems, poor motor development and low muscle tone.

Moro Reflex “aka” The Startle Reflex or Embrace Reflex: Occurs in response to any sudden movement or loud noise. The baby will respond by flinging their arms out, fanning their fingers with extension of legs and then quickly pull their arms back in towards their body in an ’embrace’ position. The reflex can elicit a negative emotional response causing the baby to cry. This reflex is typically is integrated by 4-6 months.

Functional significance:  The presence of asymmetry during the response of this reflex could indicate peripheral nerve problems to the upper extremities. The child may become over sensitive and over reactive to sensory stimulus. This results in poor impulse control, sensory overload and anxiety. Children will be over emotional and will lack social maturity. Some additional signs of a retained Moro reflex are motion sickness, poor balance, poor coordination, easily distracted, unable to adapt well to change, and mood swings.

Palmar Reflex “aka” The Grasp Reflex: This reflex is demonstrated by placing your finger or an object into your baby’s open palm, causing the baby to reflexively grasp or grip. If you try to pull away, the grip will get even stronger. This is typically integrated by 4-6 months of age.

Functional significance: Many children who fail to integrate this reflex have difficulty with independent finger movements. This may be indicative of poor handwriting skills and a poor ability to process ideas and then write them down such as; copying words is often easy, however the task of spelling words is difficult and messy.

Phasic Bite Reflex: This reflex is initiated with pressure is place on the baby’s gums. The response is a rhythmic closing/opening of the jaw with no lateral movement of the jaw. This reflex typically diminishes between 9-12 months when a controlled, sustained bite. It should be noted that the child may pull their head backward in slight extension initially to help with the bit until stable typically around 18 months.

Functional significance: This behavior is when disassociation of lips, tongue and jaw begins with true sucking. It is responsible for early munching/vertical chewing patterns.

Plantar Grasp “aka” The readiness Tester: This reflex is demonstrated by applying firm pressure to the plantar surface of the child’s foot, causing the child to reflexively flex all of their toes. This is typically integrated by 9 months.

Functional significance: This reflex is important at it integrates at the same time that independent gait/steps first become possible.

 

Pupillary Light Reflex: The diameter of the pupil constricts or dilates in response to entering light. A bright light will cause constriction while darkness causes pupil dilation to allow for more light to enter the eye.

Functional significance: Pupils that do not constrict in response to light or are       unequal in size can be a sign of a serious medical emergency including stroke,       bleeding or tumor. Seek immediate medical care if your child’s pupils do not       constrict or are unequal in size.

Rooting Reflex: This reflex occurs when a baby’s lips to the cheek is stroked by a finger. The baby turns his head towards the stimulus and opens his mouth wide in anticipation to eat. This occurs regardless of hunger state and may not be present if the infant is not hungry. This can interfere with eating if a caregiver strokes the baby’s cheek while they are feeding as it can make the baby stop drinking and turn their head towards the stimulus. This reflex is strong during the first 4 months and can last until the child’s first birthday.

Functional significance: Persistence of this reflex can interfere with the infants sucking pattern while absence of this reflex is often seen in infants with neurological impairments.

                                                              

Tonic bite reflex: This is an abnormal reflex in which an oral stimulation causes the child to bite down with tension that is difficult to release.

Functional significance: A tonic bite can be frustrating and scary for the child and can be misinterpreted by the feeder as a signal that the child does not want to cooperate with mealtime.

Tonic Labyrinthine Reflex (TLR): The gentle tilting back of the baby’s head while laying down causes the back to stiffen and arch backwards. The baby’s legs will straighten stiffly and push together. The toes point and the arms will bend at the elbows and wrists, causing the hands to become fisted and the fingers to curl. This reflex prepares the baby for movements of rolling over and crawling. This reflex typically is integrated by around 3-4 years of age.

Functional significance: Persistence of this reflex can lead to poor muscle tone. It can impede activities, which require graded co-activation of flexor and extensor muscles and children will have a tendency to walk on toes. Other signs may be motion sickness and poor balance.

Step Reflex “aka” The Dance Reflex: This reflex is present at birth despite that an infant cannot support his own weight. When the baby is held in the upright position and the feet are placed on a firm surface, the baby will place one foot in front of the other. Typically this will disappear between 6-8 weeks and then will reappear no longer as a reflex but as a voluntary movement around 8 months – 1 year.

Functional significance: Premature infants will tend to walk in a toe-heel pattern while more mature infants will walk in a heel-toe pattern.

Spinal Galant Reflex: This reflex occurs with an infant placed on their tummy or lightly supported under the abdomen with a hand under them. With a finger, one side of the baby’s spinal column is stroked from the head to the buttocks. The response occurs with the baby’s trunk curving toward the stimulated side. This reflex is typically is integrated by 3-9 months.

Functional significance: Social/learning problems can be associated with this             un-integrated reflex such as the inability to sit still, poor concentration, poor posture and hip rotation on one side, which is attributed to scoliosis. Chronic digestive issues and bed-wetting may occur beyond age of 5 years.

Suck-Swallow Reflex: Sucking a thumb and swallowing amniotic fluid can first be seen at about 12 to 13 weeks gestation and mature about 36 weeks. The ability to coordinate the reflexes to produce rhythmical sucking simultaneously to drink, swallow and breathe is known as the ‘sucking – swallowing – breathing’ sequence. This reflex should disappear between 2-5 months.

Functional significance: Persistence of this reflex could inhibit voluntary sucking.

Symmetrical Tonic Neck Reflex (STNR) “aka” The Crawling Reflex: A typical response in infants is to assume the crawl position by extending the arms and bending the knees when the head and neck are extended. This reflex typically is integrated by 11 months.

Functional significance: Necessary to achieve quadruped crawling. Developmental delays related to poor muscle tone, tendency to slump while sitting, and inability to sit still and concentrate can result if the STNR fails to diminish.

 

 

 

Questions or Concerns?

This is a brief overview of reflexes seen in typically developing children. If you are concerned that your child’s reflexes are not normal, consult with your pediatrician.

AnneMarie Finn MS CF-SLP

Additional Resources on Reflexes

 

• http://lynnhellerstein.com/wp-content/uploads/2013/01/Primitive_Reflexes-1.pdf
• http://neuroscience.uth.tmc.edu/s3/chapter07.html
• http://kin450-neurophysiology.wikispaces.com/Vestibular+Occular+Reflex
• http://www.visionhelp.com/vh_about_07.html