Primitive reflexes are involuntary movement patterns controlled by the brainstem, serving as the earliest foundation for survival and neurological development in infants. The Moro reflex, often called the startle reflex, is a protective response to sudden sensory input. When this reflex persists beyond its typical timeframe, it is considered retained, potentially impacting later development.
What is the Moro Reflex and Why is it Important?
The Moro reflex is a rapid, involuntary reaction to sudden sensory input, such as a loud noise, abrupt change in head position, or bright light. This two-phase sequence acts as the body’s primitive fight-or-flight response. In the first phase, the infant rapidly extends the arms and legs away from the body, opening the hands. This initial flaring is immediately followed by the second phase, where the limbs quickly retract toward the body in a flexion and embracing motion, sometimes accompanied by a cry. The reflex is typically present at birth but should integrate, or disappear, as the central nervous system matures, generally between two and six months of age.
Methods for Assessing Reflex Retention
Assessing Infants (Under Six Months)
Testing for the Moro reflex is a standard procedure performed by a healthcare professional. The baby is supported in a semi-reclined position, and the practitioner allows the head to gently drop backward a short distance while maintaining full support. The expected response is the characteristic sequence of limb extension followed by retraction and flexion toward the body.
Assessing Older Children and Adults
In older children and adults, retention is assessed through functional movements and postural challenges, not the infant head-drop method. Specialized practitioners, such as occupational therapists, use observation-based assessments that challenge the vestibular and balance systems. A common assessment is the “Star to Ball” movement, where the individual rapidly moves from an extended pose to a curled-up ball pose. Difficulty controlling the transition, an exaggerated startle, or struggling to maintain balance during head position changes can suggest retention. A definitive diagnosis requires a thorough evaluation by a qualified professional, correlating the physical response with developmental and behavioral history.
Common Indicators of a Retained Moro Reflex
A retained Moro reflex often manifests as a chronic state of heightened physiological arousal in older children and adults. This persistent activation of the primitive fight-or-flight system presents across sensory, emotional, and physical domains.
Indicators of Retention
Individuals frequently display sensory hypersensitivity, reacting disproportionately to environmental stimuli. Emotionally, retention is linked to elevated anxiety and internal stress, leading to poor emotional regulation and difficulty adapting to changes in routine. Behaviorally, a retained Moro can contribute to:
- Poor impulse control.
- Chronic fatigue alternating with hyperactivity.
- Difficulty filtering sensory input, impacting concentration and focus.
- Motion sickness or general clumsiness and poor coordination due to vestibular system effects.
Strategies for Reflex Integration
The goal of addressing a retained Moro reflex is to provide the central nervous system with the input necessary to complete the integration process. This is achieved through specialized reflex integration therapy, which utilizes rhythmic movements to stimulate the connection between the brainstem and higher brain centers. Therapies focus on recreating the reflex movement patterns in a controlled, repetitive, and intentional manner. Common approaches include Rhythmic Movement Training (RMT) and Masgutova Neurosensorimotor Reflex Integration (MNRI). Exercises often involve slow, rocking motions, rolling, or specific flexion and extension movements. Consistency is necessary for successful integration, as the brain needs repeated stimulation to form new neural pathways. Successful integration can lead to significant positive outcomes, including improved emotional regulation, reduced anxiety, and better coordination.