The Moro reflex is an involuntary, protective motor response present in newborns, commonly known as the startle reflex. This primitive reflex is triggered by a sudden disruption in body balance or an extreme sensory stimulus, such as a loud noise or sudden movement. In infants, the reflex involves throwing back the head, extending the arms and legs outward, and then quickly pulling the limbs back in toward the body. While normal in early development, its persistence beyond a certain age indicates an unintegrated nervous system pattern. Testing for retention in an older child is necessary when developmental or behavioral challenges suggest the reflex remains active.
The Normal Development and Integration Timeline
The Moro reflex begins developing early in gestation and is typically present in its complete form by the 32nd week of pregnancy. It is a foundational reflex that helps a baby respond to its environment and facilitates the first intake of breath at birth. After birth, the reflex helps the infant alert its caregiver to danger or need.
The reflex is designed to be temporary, typically disappearing between three and six months of age. Integration means the reflex is inhibited and replaced by more mature, controlled responses, such as the adult startle reaction. If the Moro reflex does not integrate, the child retains an exaggerated, involuntary response to stimulation.
Identifying Signs of Retention in Older Children
When the Moro reflex remains active past infancy, it can cause chronic hyperarousal, activating the body’s “fight, flight, or freeze” response too easily. This constant physiological stress manifests in various behavioral and physical indicators in school-aged children. The child may be hypersensitive to sensory input, overreacting to loud noises, bright lights, or textures like clothing tags.
A retained Moro reflex often contributes to poor coordination, making activities like catching a ball or swimming difficult. The child may also experience motion sickness due to the reflex’s connection to the vestibular system. Emotional challenges are common, including generalized anxiety, poor impulse control, mood swings, and difficulty adapting to change.
Step-by-Step Testing Procedures
Testing for a retained Moro reflex in an older child involves safely attempting to elicit a modified startle response and observing the reaction.
Seated Head-Drop Maneuver
One method is the seated head-drop maneuver. The child sits with their eyes closed and their head slightly forward, and the examiner quickly and gently guides the child’s head backward a short distance, simulating a loss of balance. A positive response is indicated by the child flinching, tensing up, or showing a delayed or exaggerated arm movement, rather than a smooth postural adjustment.
Starfish Test
Another procedure is the “Starfish” test, which evaluates the child’s ability to control the movements associated with the reflex. The child lies on their back and is asked to quickly stretch their arms and legs out wide like a star, and then draw them back in tightly like a ball. A retained reflex may cause the movements to be jerky, uncoordinated, or difficult to perform slowly and purposefully. Although these tests can suggest retention, any suspected positive result should be confirmed by a trained professional, such as a developmental pediatrician or occupational therapist.
Corrective Measures for Retained Reflex
Integration of a retained Moro reflex is achieved through specific, repetitive, and rhythmic movements that mimic the natural motions a baby performs to integrate the reflex. These therapeutic exercise programs are typically administered by an occupational or physical therapist specializing in primitive reflex integration. The goal is to stimulate the nervous system and help the brain form new, mature neural pathways.
One common exercise is the “Star to Ball,” where the child lies on their back and moves their limbs in a controlled, slow manner from an outstretched position to a curled, fetal position. Consistent daily practice of these prescribed movements helps to override the involuntary reflex pattern and allows the child to develop better motor control and emotional regulation.