Reflexes Role in Child Development
By Jenn Gile, OTR/L; Jessica Tallent, OTR/L; Amanda Mazerall, OTR/L
Kids Place Pediatric Occupational Therapists
A reflex is an automatic, instinctual movement pattern that occurs in response to a stimulus. There are several primitive reflexes that are present at birth or emerge shortly after birth and integrate within the first few years of life. Each of these reflexes serves a purpose in our development such as learning to move, visual development, protection, and learning to interpret sensory input from our environment. When these reflexes do not integrate as expected, we may see long term affects in how we are able to function in our daily lives.
The Moro Reflex, commonly referred to as infant startle reflex, is present at birth and typically integrates at, or around, 4 months old. This reflex is triggered by sudden changes in sensory stimuli which are perceived as a threat. Changes can occur in any sensory system to create the startle including bright lights, loud noises, unexpected touch, or sudden changes in head position in space. When this reflex is triggered, the baby’s arms and legs open up and away from the body simultaneously, stress hormones release, breathing shallows, heart rate increases, and blood moves toward the limbs. As this reflex repeats, babies learn to filter which stimuli are true threats warranting a response and which stimuli can be ignored. This is an important step in maturing the nervous system, developing a mature ‘fight or flight’ response, and developing appropriate responses to sensory input in our environment. An unintegrated or retained Moro reflex can have a significant impact on functional skills like sleep disturbances, easily triggered emotional outbursts, significant shyness, poor balance, poor coordination, poor endurance and difficulty adapting to change, to name a few.
Signs you or your child may have a retained Moro reflex may include:
- Difficulty tolerating sudden changes in head position
- Hypersensitivity or startle response to bright lights, loud noises, sudden unexpected touch, intense odor, etc.
- Difficulty separating arms and legs – for example when toes are turned in, arms also turn in and when toes are turned out, arms turn out
- Difficulty in several functional skills
Asymmetrical Tonic Neck Reflex (ATNR)
ATNR is a primitive reflex found in newborns that is typically integrated by 6 months of age. Nicknamed the “fencing reflex”, this response causes an infant’s arm and leg to extend on the side to which the face is turned and causes the opposite leg and arm to flex. As an infant, ATNR affects one’s ability to roll, crawl, and use alternating patterns with legs and arms because the act of turning the head will cause a hand to involuntarily extend.
As your baby gets older, deficiencies with motor planning, bilateral coordination, and vision become more apparent as the retained reflex will restrain a child’s ability to cross the midline of their body with their hands, feet, and eyes. Implications of a retained ATNR may include but are not limited to difficulties with visual tracking, binocular vision, listening, attention, spelling, hand writing, hand-eye coordination, bilateral coordination, sense of direction, short term memory, gross motor tasks, and balance.
Symmetrical Tonic Neck Reflex (STNR)
STNR is a primitive reflex found in a baby around 6 months of age and is typically integrated by 12 months. This reflex is a precursor to crawling. When babies are on the floor on their belly, they will lift or extend their head and neck causing their arms to extend and the lower body to flex. When this reflex is activated the result is hands and knees position.
If this reflex is not integrated, the child may have difficulty advancing and crawling with a symmetrical pattern. You may see that the child bear crawls (arms and legs extended), butt scoots, or may skip crawling all together. There are many implications if a child skips crawling and/or if this reflex does not integrate. Crawling is very important for proper vision development. It helps babies with visual tracking, development of depth perception as well as being able to shift focus from one place to another. If these skills are not developed, it can affect reading, writing, eye-hand coordination, and many other areas later in life. Crawling also helps to develop the arches in the palms of our hands that are necessary for proper grasp patterns and functional hand use.
If your child has an unintegrated STNR, they may display poor posture, decreased balance, poor depth perception, poor eye-hand coordination, trouble with reading/writing, trouble copying from the board, an inability to keep head off of table while writing, w-sitting position on the floor, and may exhibit characteristics of ADHD.
If you think your child has unintegrated reflexes, please schedule an occupational therapy evaluation. Once your child is evaluated, your occupational therapist will help these reflexes integrate and provide an appropriate home exercise program.