Primitive Inhibitory Reflexes:
Primitive Inhibitory Reflexes are the developmental milestones your child should be reaching as their brain, and body grow. They are hardwired into our brains, and babies use them during development as the building blocks for survival and refinement of purposeful controlled movements. As our brains mature, the primitive reflexes are inhibited (dampened) by more complex motor pathways from the brain, cerebellum and brainstem.
These Primitive Reflexes are necessary for a baby’s survival in the first few weeks of life, and provide the training needed for many voluntary skills needed later on in life. They should be inhibited and controlled by higher brain centers when the neural structures have developed to keep them inhibited.
If these primitive reflexes remain active, weakness or immaturity occurs within the nervous system. Prolonged primitive reflexes prevent the development of succeeding postural reflexes. Depending on the degree of abnormal reflex activity, poor organization of nerve fibers can affect gross muscle and fine motor control, balance, coordination, sensory, emotion, speech articulation, swallowing, cognition and more. These are a few common symptoms of Neural Developmental Delays due to primitive reflexes which have not been integrated causing delay in brain function.
This primitive reflex is necessary for the development of swallowing. It is needed for the coordination between respiration and oral function and development of speech articulation; all of which are essential preparations for babbling and speech development. If the tongue remains too far forward in the mouth to allow effective chewing, a retained oral reflex prevents maturation of swallowing, feeding, speech articulation and manual dexterity difficulties. You will see this with poor articulation, jaw deviation (temporal mandibular dysfunction), prolonged thumb sucking, messy eating, dribbling, slurring of speech, etc.
The Plantar Reflex emerges in utero at around 11 weeks and should be integrated about 7-9 months after birth. As the infant begins to stand up, usually by the age of one, the Plantar Reflex should disappear. The reflex is elicited when pressure is applied to the sole of baby’s foot between the toes and the arch. If this is done to a baby before he is 7 months, the response will be that the toes will bend inward in flexion. If the toes fan and expand outward, it is an indication of the Babinski reflex. The Plantar Reflex is usually present in children who toe walk.
If the Plantar Reflex remains active after the first year of life, foot positioning will be more difficult resulting in problems with balance, posture, gait, and walking. In addition, Harald Blomberg (2012) has found that a retained Plantar Reflex can also cause tension in the jaw, issues with clenching and grinding of the teeth and can affect speech articulation and phonological challenges similar to a retained Babkin Reflex.
Emerges around 9 weeks in utero, is active during the first 3 months after birth, and should be integrated at about 4 months. This reflex helps the baby to stimulate the breast causing breast milk to flow while breastfeeding. The pattern of the Plantar Reflex in the feet is very similar to the Babkin Reflex in mammals when they stimulate the breast with their paws. When infants suck, there is not only involuntary movement of their hands, but many times their toes and feet curl.
When a Babkin Reflex is not integrated you’ll notice when a child writes or does other fine motor work, like playing an instrument or using scissors, there will be involuntary movements of the mouth and tongue. Research (Blomberg 2012) has found that the Babkin Reflex may influence the movements of the sphenoid and temporal bones, and directly impacts speech, articulation, and even phonological ability.
Some symptoms of a nonintegrated Babkin Reflex
- Low muscle tone in the hands
- Poor handwriting; impaired fine motor skills
- Challenges with speech and articulation; speech delay
- Tensions of the jaw; grinding or clenching of teeth; tensions in the body, especially tightly clenched fists
- Can affect reflexes responsible for eating, therefore can be seen in eating disorders and excessive nail biting
- Retention of long-term sucking, such as biting or sucking on ones clothes or objects in the hands
This reflex is an early intrauterine, rather than primitive reflex that emerges in the womb sometime during the second month after conception. This Reflex is one of the earliest reflexes and the most characteristic reaction is withdrawal away and/or a temporary freeze from any sudden, unexpected or threatening stimuli, event or trauma. When this happens, the fetus shuts off its environment by producing stress proteins and literally becomes paralyzed by fear.
Some symptoms of a nonintegrated Startle Reflex
- Low tolerance to stress; a sense of being frozen or feeling stuck
- Can cause lifelong challenges related to fear and underlying anxiety
- Social isolation and fear of new situations or activities; extreme shyness
- Fear of failure; perfectionism
- Helplessness; depression
- Hypersensitivity to one or several of the senses, especially touch, sound and light
- Sleeping and/or eating disorders
- Panic attacks and social phobias are often seen in adults
- Temper tantrums; holding one’s breath; oppositional or aggressive behaviors can be seen.
- Difficulty making or maintaining eye contact or intense staring often without blinking.
Tonic Labyrinthine Reflex/Symmetrical Tonic Neck Reflex (head righting reflex):
This reflex assists the child in getting up on his hands and knees and eventually crawling using a cross lateral movement pattern, and becomes integrated when the infant kneels on all fours and begins to rock back and forth.
This reflex is another very important reflex for academic success in school. A child may have difficulty maintaining certain postural positions if this reflex is not integrated. The upper and lower parts of the body will remain at odds with each other. This is most notable when the child sits at a desk or table and is asked to read or write. When the child looks down, the arms bend causing the child to lay their head on the table instead of maintaining an upright reading or writing posture. The tonic labyrinthine reflex is not only important for overall posture and muscle tone of the back and neck, but is also very important for training vision, especially near and far visual focus.
Some symptoms of a nonintegrated Symmetrical Tonic Neck Reflex
- Problems crawling
- When reading or writing often supports head with hand or ends up slumped and lying over the table or book. May prefer to read or write while standing.
- In order to sit upright in a chair, a child sits on his legs or wraps them around the legs of the chair. If he has to sit on the floor, he will often sit with his legs in a “W” position.
- Attention and focus difficulty; trouble staying on task; squirming or fidgeting
- Vision difficulty; focusing at far and near distances
- If head control and strength is lacking, such as seen in a floppy baby, decrease muscle tone, cerebral palsy, underdeveloped cerebellum. Children who have a retained TNR when they begin to walk, are unable to acquire a true gravitational sense, and because head movements alter muscle tone will throw their center of balance off.
- If a child doesn’t have a reference point in space they’ll have difficulty in judging space, distance, depth perception and speed. These are needed so that you have knowledge of where your head, body, and limbs are in relationship to your personal space. Astronauts will experience this when they return from space; losing balance, orientation, spatial and directed awareness. They also begin to reverse numbers and letters, and begin writing right to left.
The cerebellum is a part of the brain responsible for balance and also has a clear role in motor learning. The cerebellum does not abolish movements; it makes them slow, inaccurate, rough and variable. The cerebellum compensates for different loads and muscle lengths, improves movement accuracy and smoothness, and an intact cerebellum is a ‘prerequisite’ for optimal ocular motor function. The cerebellum ‘fine-tunes’, eye movements so they work together to maintain images clearly, and the vestibular system sends information to the cerebellum to coordinate incoming sensory information.
The cerebellum communicates with ALL areas of the brain:
- the vestibular system for involuntary posture (subconscious posture)
- the spinal cord for fine tuning of movement eg. walking and running;
- the cerebral cortex via the brainstem for fine muscle coordination – especially the hands and mouth.
The most lateral area of the cerebellum’s function is:
- word association
- mental imagery of movement sequences (ideation)
- practice related learning
- judging time intervals (understanding time, date, months, yr) & speed of moving stimuli
- rapidly shifting attention between sensory modalities
- cognitive operations in 3D space (mental imagery)
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