Primitive Reflexes: Why Are They Important?

Primitive reflexes prepare the neonate to move against gravity, which gradually leads to voluntary movement through integration during the first months of life. Mature responses in a child's psychomotor progress can only occur if the central nervous system has reached maturity. The process consists of transitioning from a brain stem reflex response to a cortically controlled response (Gieysztor et al., 2018). If primitive reflexes are retained beyond the average developmental period, there is the potential to disrupt the maturation progression and impair the brain's ability to process sensory information effectively. Severe persistence of primitive reflexes predominantly indicates physical problems such as cerebral palsy. Milder persistence is associated with less severe disorders such as learning problems. The inhibition of primitive reflexes enables the development of motor skills allowing the infant to act on and interact with their environment in increasingly complex ways (Chinello et al., 2018). The child with nonintegrated reflexes may have difficulty with motor coordination, this can manifest in difficulty with running, cycling, and balance, and they may be described as clumsy. The child may have difficulty throwing and catching or avoid games involving physical or movement activities (Gieysztor et al., 2018). If retained, the asymmetrical tonic neck reflex (ATNR), symmetrical tonic neck reflex (STNR) and labyrinthine tonic reflex (TLR), along with the plantar reflex, palmar reflex, rooting reflex and spinal Galant reflex, decrease the brain's ability to process sensory information efficiently (Gieysztor et al., 2018).

The Moro reflex is also referred to as the 'startle reflex.' The Moro reflex is the earliest primitive reflex to emerge and forms a strong foundation for future life experiences. When you fail to support or hold your baby's neck and head or if your baby becomes startled by a loud noise, bright light or sudden touch, the arms of your baby will thrust outward and curl, which looks like an attempt to embrace themselves. If retained, the child/adult may be hypersensitive to other sensations, over-react to stimulation and be in a constant state of "fight or flight." This state will lead to overactivity of the sympathetic nervous system, including the adrenal glands. Due to the constant demands placed on them, they may become fatigued, leading to allergies, asthma, a depressed immune system, and, ultimately, chronic illnesses. Other observable social/learning problems associated with a retained Moro reflex include an inability to focus on one thing at a time, poor impulse control, emotional immaturity, a tendency towards becoming withdrawn or timid, distractibility, difficulty playing ball games, and aggressive, anxious, or highly excitable behavior. Sensory systems associated with the Moro reflex include the auditory, tactile, visual, vestibular, and proprioceptive systems.

Difficulties associated with a retained rooting reflex include social/learning problems, poor articulation, tactile sensitivity around the face, messy eating, and poor manual dexterity. The tactile and proprioceptive systems are associated with the rooting reflex.

The spinal Galant, like the ATNR, is important in the birthing process because it facilitates the movement of the hips as the baby descends into the birthing canal. Observable social/learning problems associated with a retained spinal Galant reflex include an inability to sit still, "ants in the pants," possible scoliosis, poor concentration, poor posture, hip rotation on one side when walking, chronic digestive issues, and bedwetting beyond the age of 5 years. The sensory systems associated with the spinal Galant reflex include auditory, vestibular, visual, and proprioceptive systems.

Signs of a retained ATNR include possible scoliosis, poor handwriting, difficulty expressing ideas in written form, difficulty with eye-tracking, difficulty with visual-motor coordination, and difficulty with tasks that require crossing the body's mid-line (reading/writing), and difficulty with bilateral coordination. Every time the head turns, an arm may follow it with fingers open. It will take the individual a lot of effort and concentration to hold the hand still while writing when the head has to move to look at another paper or the whiteboard. An older child or adult may complain of chronic or recurrent shoulder or neck injury/pain, often on the same side of the body. The sensory systems associated with the ATNR include auditory, vestibular, visual, and proprioceptive.

The symmetrical tonic neck reflex has a very short life span and undergoes inhibition when the child starts to crawl. It enables the baby to get off the floor for the first time but does not allow mobility. Typical developing babies go through a period of "rocking" on hands and knees, a process that inhibits the STNR, so crawling may ensue. If the STNR remains strongly active for too long, then fluent crawling may never be achieved. Bending the legs as a result of head extension assists in inhibiting the reflex and encourage the infant to fixate their eyes at a distance. Bending the arms in response to flexion of the head will automatically bring the child's vision back to the near point, training the eyes to adjust from far to the near point and back again. The retained STNR can also be characterized by poor posture, poor eye-hand coordination and focusing difficulties. Children with a retained STNR may have problems with sitting still at a desk or learning to swim and usually do not feel comfortable with ball games.

The tonic labyrinth reflex prepares the baby for rolling over, crawling on all fours, standing and walking. Problems associated with a retained reflex include difficulty keeping the head in a flexed position, trouble paying attention when sitting at a desk or reading, poor posture, poor balance, motion sickness, dyspraxia, toe walking, hypo or hyper-tonus (muscle tone), a dislike for a physical education class, poor sense of rhythm/timing, oculomotor difficulties (reading/writing), orientation and spatial difficulties. The sensory systems associated with this reflex include the vestibular, proprioceptive, auditory, and visual.

The disappearance of the palmar grasp reflex is significantly related to the commencement of the voluntary use of the hands. The absence of this reflex usually reflects peripheral (i.e., root, plexus, or nerve) or spinal cord involvement, especially if asymmetrical responses are noted. Lesions of the upper brain structures can affect the response. The response may be increased and retained longer compared to typical infants on the affected side(s) of the upper limb(s) in infants with spastic hemiplegia or quadriplegia, whereas it is very weak in infants with cerebral palsy (CP) of the athetoid type (Futagi et al., 2014).

A primitive reflex is regarded as abnormal when it is absent or diminished during the period it should be actively elicitable or is present beyond the age limit for its disappearance/inhibition. An exaggerated reflex can also be abnormal (Futagi et al., 2014). In addition to the testing descriptions listed below, many therapists have adopted their way of testing the reflexes during their work with children. The suggestions below have been prevalent in the literature for many years and will, at the very least, give the new examiner a starting point for reflex testing.

Moro Reflex: The subject is supported in a semi-reclined position; the examiner drops the head backward and observes for a startle response. If no startle is noted, the test is negative. If there is noted abduction, extension or flexion or external rotation of arms with extension and abduction of the fingers, the test is considered positive. Positive reactions after 4 months may be an indication of delayed reflex integration. This reflex should disappear between 2-4 months of age.

Rooting Reflex: When you stroke the subject's cheek, the reflex is elicited. They will turn towards you, usually looking for food. This reflex is very useful for breastfeeding. The reflex should be inhibited by 3-4 months of age.

Spinal Galant Reflex: the reflex is elicited by holding or laying the subject on their stomach and firmly stroking along one side of their spine. A positive reaction is for the subject to flex sideways toward the stimulated side. This flexion is one of the reflexes tested in newborns to help rule out brain damage at birth. Stimulation down both sides of the spine at the same time simultaneously activates a related reflex that will reduce urination. This reflex should be inhibited by 3-9 months of age.

ATNR: The subject being tested is supine with the head positioned in midline and arms and legs in extension. The examiner turns the head to one side; if there is no reaction, the test is negative. If the examiner notes an increase in extensor tone or extension of the arm and leg on the face side and an increase in flexor tone or flexion of the arm and leg on the skull side, the test is considered positive. This reflex should be inhibited by 6 months of age. Ayres suggested testing of the ATNR could be done in a quadruped position, beginning with the child's head in midline and rotating to either side, looking for increased muscle tone in the arm toward which the child is facing, for example, if the head is turned to the right, an increased tone would be noted in the right arm and decreased tone in the left arm. She reports that the child's head can be moved passively, the child's eyes should be closed, and the elbows should be slightly flexed before the head is turned (Ayres, 1989).

STNR: The subject being tested is in a quadruped position or over the examiner's knees. The examiner raises the subject's head into extension. The test is considered negative if no change is noted in the subject's muscle tone in the arms or legs. If the subject's arms flex, legs extend, or tone dominates, it would be considered a positive reaction. This reflex should be inhibited by 6 months of age. Ayres suggested that the STNR can be assessed in the quadruped position or during a clinical situation. In quadruped, the head is held in the midline at 0 degrees of flexion/extension; the head is flexed, and increased flexor tone in the arms is noted with a positive response. When the head is extended, a positive response would be increased extensor tone in the arms.

TLR: The reflex may be tested in supine or prone. In supine, the subject being tested is positioned with the head at midline and arms and legs in extension. The examiner passively flexes the arms and legs; if there is an increase in extensor tone, the test is considered positive. In prone, the head is actively extended in the midline by the subject being tested; if there is no noted increase in the flexor tone of the head, trunk, arms, or legs, the test is negative. If the subject cannot extend the head, retract the shoulders, or extend the trunk, arms, or legs, the test is considered positive. The reflex should be inhibited by 2-4 months of age (Gieysztor et al., 2018). Ayres suggested that the reflex may be assessed using the prone extension and supine flexion positions (Ayres, 1989).

Palmar Reflex: the reflex is elicited by the examiner inserting their index finger into the palm of the infant from the ulnar side, applying light pressure into the palm. The subject is awake and lying in a symmetrical supine position on a flat surface. A positive response is noted if there is flexion of all the fingers around the examiner's finger and is seen in two phases: finger closure and clinging. The latter occurs as a reaction to the proprioceptive stimulation of the tendons of the finger muscles due to slight traction after applying pressure to the palm. The palmar grasp reflex can be elicited in infants during the first 3 and 6 months before decreasing in intensity and disappearing by 6 -12 months of age (Futagi et al., 2014).

According to Bell, without reflex integration, it may be impossible to correct motor function and help clumsy children reach the same psychomotor level as typical peers. In order to prevent psychomotor delays in older children, the degree of reflex integration in preschoolers should be assessed and reflex therapy initiated. Treatment should focus on the root of the problem, not just the symptoms; training should focus on inhibiting the reflexes and then on the child's abilities (Bell et al., 2019).

Blythe reports that neuro-developmental delay (NDD) is defined as the continued presence of a cluster of primitive reflexes above one year and the absence or underdevelopment of postural reflexes above the age of three and a half years. Primitive reflexes that persist in this way and underdeveloped postural reflexes are said to be aberrant and represent a structural weakness in the central nervous system, which will affect the development of later complex skills such as balance, motor control, oculomotor functioning and perception.

If the infant shows delayed integration of reflexes, they may participate in an infant motor guidance program. In this program, the infant's caregiver will make the movements for them versus an older child or adult completing the integrating movement patterns independently. The program is designed to assist the infant in continuing the normal sequence of development and reduce developmental motor delays in children later diagnosed with ADHD or autism spectrum disorder.

It is recommended that The motor guidance program is performed five minutes twice a day for one month on each reflex. After a month, move on to the next reflex movement pattern until all five reflex patterns have been integrated. The best times to apply the movement patterns were reported upon waking and before sleep.

The Starfish is an exercise suggested to integrate the Moro reflex; there are YouTube videos that demonstrate many of these exercises if the reader would like a visual demonstration. For the Starfish, the individual should have the arms and legs spread out in a loose, relaxed position with the head slightly extended. The arms and legs move or should be moved all together towards each other into a fetal position with arms and legs drawn into the chest. Move the head, so the chin touches the chest. Hold the position for two seconds, then slowly move the arms and legs back to the Starfish position. Remain in the Starfish for two seconds. The movement should be safe and relaxed. In the fetal position, the left leg and left arm cross over the right leg and right arm. When the movement is repeated, cross the right leg and arm over the left leg and arm. These movements complete one repetition. It is very important to move the head and neck all at the same time. The exercise should be repeated a total of 5 times.

For the tonic labyrinth reflex exercise, the individual is lying in the prone position with arms and legs relaxed. The therapist lifts the right arm (may want a bright object such as a rattle in hand) while the individual is looking, move the right hand to the right and see if they can follow the hand until the arm is straight out to the side about 90 degrees from the starting point. You can prompt the individual to look using verbal cues. After you have moved 90 degrees from the starting point, move the arm back until it is straight in front of the individual again. Repeat with the left arm, lifting and moving it the same way. When the left arm is back in front of the individual, let the arms and hands rest on the floor with the head down. This sequence completes one cycle. Repeat for three cycles. The key is to relax the legs and move the arms as slowly as possible.

The spinal Galant exercise is similar to making angels in the snow. Lying in a supine position with both feet together, legs straight, and arms down to the sides of the body. Very slowly, move the arms and legs out like a jumping jack. The hands should touch as the legs reach their widest point, then slowly return to the starting position. Each angel in the snow should last at least 20 seconds. Do three angels to complete the exercise.

The ATNR exercise begins with the individual lying prone with arms and legs straight and the head to one side. Bend the arms and legs on the same side the face is turned (like creeping but flat on the stomach). Turn the head to the other side, move the arm, then the leg back to the starting position and wait 5 seconds before repeating the arm and leg flexion and abduction on the other side of the body. This sequence is considered one cycle. The author suggests 3 full cycles intending to relax the body as much as possible. For pictures of this exercise, see the references page to find the article written by Dr. Berne.

The STNR exercise begins with the individual sitting on their feet and calves, lowering the head until the forehead is touching the surface in front of the knees, and straightening the arms out above the head. Move the head and body into a crawling position, then move the infant backward down into the starting position. Continue the back and forth movement for three minutes or approximately 18-25 cycles.

There is limited research that provides specific intervention activities to integrate primitive reflexes. These activity suggestions were suggested at a conference sponsored by Summit Professional Education in Schaumberg, Illinois, on 12-5-2019, presented by Tina Pipher, MA, OTR/L. Pipher suggests choosing activities that move the individual in the opposite direction of the reflex, for example, working flexibly if the individual has a positive Moro reflex. She also suggests considering the sensory input that triggers the reflex response, such as movement, sound, or vision — using activities that stimulate the vestibular system to inhibit the TLR and STNR and starting with slow homolateral movements when remediating the ATNR.

Ayres provides exercises to inhibit the STNR and ATNR using a bean bag and specific body movements on page 106 of her book "Sensory Integration and Learning Disorders." She makes it clear that these reflexes are always present in all people but states that the degree to which these reflexes have been integrated into the nervous system needs to be evaluated (Ayres, 1989).

A 6-year-old male with a medical diagnosis of auditory processing disorder was described as shy with low self-confidence due to a lack of coordination and auditory and speech issues. His parents reported that their son often felt different than other children his age and did not enjoy playgroups or social interactions. During the assessment, multiple retained primitive reflexes were noted, including ATNR, Palmar, Galant, Rooting, and Babinski. In addition to chiropractic adjustments, the child was given cross crawl integration exercises to improve left/right brain communication and primitive reflex remediation exercises to inhibit the ATNR. Brushing techniques inhibited the other retained primitive reflexes (Rooting, Palmar, Gallant, and Babinski). By the 14th visit in 3 months, the child was reported to have improved independence, increased self-confidence, and significant improvements in coordination (Rubin, 2015).

Good evidence suggests that primitive reflexes retained beyond one year of age may adversely impact an individual's sensory-motor performance. When an individual is referred for an occupational therapy evaluation, testing or observing for the presence of retained reflexes would be beneficial to rule out their presence and possible influence on higher-level skill development. The examiner can use this information to inform the plan of care.

• Ayres A. Sensory Integration and Learning Disorders 9th printing. Los Angeles, CA: WPS; 1989.
• Bell C, Whitney, J, Deiss T, et al. The effect of the MNRI method on neurotransmitter biomarkers of Individuals with neurodevelopmental disorders. Neuroscience & Medicine. 2019; 10: 292-321. 10.4236/nm.2019.103022.
• Chinello A, Di Gangi V, Valenza E. Persistent primary reflexes affect motor acts: Potential implications for autism spectrum disorder. Res Dev Disabil. 2018;83:287-295.
• Futagi Y, Toribe Y, Suzuki Y. The grasp reflex and moro reflex in infants: Hierarchy of primitive reflex responses. International Journal of pediatrics. 2012; 2012:191562. Visit Source.
• Gieysztor EZ, Choinska AM, Paprocka-Borowicz M. Persistence of primitive reflexes and associated motor problems in healthy preschool children. Arch Med Sci. 2018; 14(1): 167-173.
• Rubin D. Reflexes. tcl online today. 2015. Accessed 12-01-2019. Visit Source.