Published by Omega Functional Health | Wheat Ridge, Colorado
There is a question that rarely gets asked in a standard developmental evaluation, even though the research increasingly points to it as one of the most important factors in child developmental delay. That question is whether a child’s primitive reflexes have been properly integrated.
Most parents have never heard the term. Most pediatric workups do not screen for it. But for children who are struggling with coordination, sensory sensitivity, attention, emotional regulation, or social development, retained primitive reflexes may be one of the most significant and most treatable contributors to what is happening in their nervous system.
What Primitive Reflexes Are
Every baby is born with a set of automatic, involuntary movement patterns called primitive reflexes. These are not voluntary or learned. They originate in the brainstem, below the level of conscious control, and they are hardwired into the nervous system before birth.
Primitive reflexes serve specific developmental purposes. They help the baby navigate the birth canal. They initiate feeding. They drive the early sensory-motor experiences that build the brain’s foundational neural pathways. When a baby turns their head and their arm extends automatically on the same side, that is a primitive reflex at work. When a newborn roots toward a touch on the cheek, that is another. These movements are not random. They are the brain’s first language, and they are doing critical developmental work from the moment of birth.
Under normal developmental circumstances, primitive reflexes are integrated by the end of the first year of life. Integration means they are absorbed into more complex voluntary movement patterns as the higher brain systems come online and take over. The brainstem reflex that once drove an automatic arm extension gives way to the cortically controlled, coordinated reaching and grasping of a toddler.
When this integration does not happen on schedule, the retained reflexes continue generating automatic, brainstem-level responses that interfere with the development and function of the higher brain systems. The child’s nervous system is still running foundational programming at a stage when it should have moved on to more complex operations.
Dr. Robert Melillo and his colleagues have established through published research that retained primitive reflexes are among the most common neurological findings in children with developmental delay, learning difficulties, behavioral dysregulation, and neurobehavioral conditions including ADHD, autism spectrum disorder, dyslexia, and sensory processing disorder. Retained primitive reflexes are not a fringe concept. They are an increasingly well-supported explanation for why so many children struggle in ways that behavioral strategies and academic accommodations alone cannot fully resolve.
Melillo R. Disconnected Kids. 3rd ed. TarcherPerigee; 2024.
How Retained Reflexes Create Bottom-Up Interference
The concept at the core of this clinical picture is what Dr. Melillo calls bottom-up interference. The brain builds from the bottom up. Lower brain systems, including the brainstem, cerebellum, and vestibular system, must establish themselves before the higher cortical systems can develop and function properly. When retained primitive reflexes keep the brainstem in a state of chronic activation, the interference travels upward through the brain’s hierarchy and limits what the higher systems can do.
This is why a child with retained primitive reflexes may look like an attention problem, a behavioral problem, or an emotional regulation problem at the level of the cortex, while the actual driver of the presentation is occurring much lower in the nervous system. Behavioral interventions applied at the cortical level cannot reach the brainstem-level patterns creating the interference. That is not a failure of the intervention. It is a mismatch between the level of the problem and the level of the solution.
The Most Clinically Significant Retained Reflexes
Several primitive reflexes are particularly important in the context of child developmental delay in Colorado.
The Moro reflex, sometimes called the startle reflex, is one of the most clinically significant. In infancy, it causes the baby to throw their arms wide in response to sudden movement or sound. It should be integrated by three to four months of age. When it is retained, the child has a nervous system that is chronically primed for threat response. Their autonomic nervous system spends excessive time in sympathetic activation. From the outside, this looks like heightened anxiety, sensory overreactivity, emotional volatility, and difficulty with transitions. The child is not being difficult. Their brainstem is firing a reflex pattern that should have been inhibited months or years ago.
The Asymmetrical Tonic Neck Reflex, or ATNR, drives the automatic extension of the arm on the side the head turns toward. It should be integrated by six months. When it persists, it interferes with crossing the body’s midline, affects hand-eye coordination, and creates significant obstacles to the academic tasks that require both: reading, writing, and throwing a ball.
The Symmetrical Tonic Neck Reflex, or STNR, links head position to arm and leg tone. When the head lifts, the arms extend and the legs flex. When the head drops, the arms flex and the legs extend. It should be integrated by approximately nine to eleven months. When retained, it interferes with crawling, with seated posture, and with the ability to coordinate upper and lower body movement independently.
The Tonic Labyrinthine Reflex, or TLR, is driven by the position of the head relative to gravity. It should be inhibited in the first months of life. When retained, it affects muscle tone throughout the body, disrupts balance and spatial orientation, and contributes to the postural difficulties commonly seen in children with developmental concerns.
What Retained Reflexes Look Like in a Child
The presentations associated with retained primitive reflexes can be subtle and are frequently misattributed. A child who struggles to sit still in a chair may have a retained STNR that makes maintaining seated posture neurologically difficult. A child who avoids writing or resists crossing the midline during activities may have a retained ATNR. A child who is easily overwhelmed by sensory input, prone to emotional outbursts, and struggles with anxiety may have a retained Moro reflex driving chronic sympathetic activation.
None of these children are choosing these behaviors. Their nervous systems are generating them automatically, at a level below conscious control, because an early reflex pattern was never properly integrated.
How Omega Functional Health Evaluates and Addresses Retained Reflexes
Primitive reflex screening is a central component of the neurological evaluation at Omega Functional Health. Each reflex is assessed individually to determine whether it has been integrated or whether it remains active and is contributing to the child’s clinical presentation.
When retained reflexes are identified, the care program includes specific exercises designed to integrate them. These exercises are not generic. They replicate and complete the developmental movement sequences the reflex should have been integrated through in infancy, delivering the sensory-motor input the nervous system needs to inhibit the reflex and allow the higher brain systems to develop more freely.
This work is done in combination with a broader neurological program targeting the specific hemispheric imbalances identified in the evaluation. The 90-day care framework allows for a structured progression, mid-point reassessment, and a final phase focused on consolidating the neurological changes achieved.
Families in Colorado whose children have a history of developmental delay, coordination difficulties, sensory sensitivities, or behavioral and learning challenges are welcome to contact Omega Functional Health to schedule a complimentary virtual consultation. The initial conversation is with parents, at no cost, and is focused on whether this approach is a good clinical fit before any in-office time is scheduled.