retained Reflexes
Primitive reflexes play a crucial role in survival and early development. We are all born with primitive reflexes and they should, ideally, naturally integrate – sometimes, they don’t which can potentially cause problems for children in many areas.
THE FOUNDATION OF DEVELOPMENT
Retained primitive reflexes, which typically integrate and disappear by 12 months of age, or sometimes by two to three years, play a crucial role in a child's development. Their integration allows for more sophisticated movement patterns and higher-level learning. For example, an infant must develop head and neck control before sitting upright independently. Failure to integrate these reflexes can hinder development and the acquisition of advanced skills.
Retained primitive reflexes, those persisting beyond the expected integration period, can impede development in various areas. Since many reflexes are interconnected, the retention of one often indicates the presence of others.
A 2016 study found that retained reflexes could disrupt natural development, leading to difficulties in social, educational, and psychomotor domains.
Activities typically associated with childhood, such as playing with peers, running and jumping, learning to read and write, and performing self-care tasks, can be adversely affected by these retained reflexes.
CAUSES OF RETAINED REFLEXES
Although research into the exact causes of retained primitive reflexes is limited, several potential factors have been identified:
Trauma during pregnancy
Trauma during or after birth
Exposure to toxins, drugs, or tobacco in utero
Stroke in utero
Caesarean section delivery
Premature birth
Prolonged jaundice
Feeding problems in the first 6 months of life
Developmental motor delays
Limited floor time during infancy
This list is not exhaustive, but it highlights some factors that have been associated with retained primitive reflexes. It is important to recognise that the presence of these factors does not guarantee the retention of primitive reflexes in a child.
PREVALENCE OF RETAINED REFLEXES
While there are no extensive studies on retained primitive reflexes comparable to those for Autism or ADHD, several smaller studies provide insight into their prevalence. Clinical experience suggests that retained primitive reflexes are more common than often assumed.
These reflexes exist on a spectrum, with partial integration possible.
Testing typically uses a scale from 0 (fully integrated) to 4 (highly retained).
One study examining 21 preschool children found only one child without retained reflexes. About 29% scored a 1 or 2, while 50% scored a 3 or 4.
The most common retained reflexes were:
TLR: 95%
ATNR: 86%
Left ATNR: 81%
STNR: 67%
Another study of 35 healthy children aged 4 to 6 showed that 89% had at least one retained reflex. A larger study with 53 children aged 5 to 7 found that all participants had at least one active reflex, with the most common being STNR, ATNR R, and ATNR L.
COMMON RETAINED REFLEXES EXPLAINED
With children, Occupational Therapy often focuses on self-care tasks, social skills, motor development, and sensory integration, all of which can be influenced by retained primitive reflexes.
The six primitive reflexes most commonly addressed in Occupational Therapy are:
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The Moro Reflex is present at birth - it is an involuntary movement in response to sudden stimuli.
A report from 2020 reported that the Moro Reflex can be seen as early as 25 weeks postconceptional age and usually is present by 30 weeks postconceptional age.You’ve heard of the startle reflex, right? That’s the Moro Reflex!
The Moro Reflex should be integrated - not present - by six months after birth, at the latest.
Some potential symptoms of a retained Moro Reflex in infants and older children are:
Motion sickness
Decreased eye contact
Light and sound sensitivity
Allergies, poor immune system
Anxiety and mood swings
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The TLR is closely linked to the Moro Reflex and is seen with movement of the head forwards or backwards - providing a method of response to gravity (an infant experiences gravity for the first time after birth, so this reflex is a direct response to this newfound challenge). The TLR develops in utero and has a direct influence on the development of muscle tone throughout the body.
The TLR should be integrated - not present - by as late as 3 years old. However, it can be integrated as early as six months (note, this is the approximate age when the Moro Reflex should be integrated - quite the connection!).
Some potential symptoms of a retained TLR in toddlers and older children are:
Challenges with crawling
Poor posture, low muscle tone
Vision challenges
Auditory processing challenges
Poor sense of space, time, and organization
Challenges with sports
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The Palmar Grasp Reflex is an involuntary response to stimuli on the palm of the hand. This assists a newborn with grasping objects before they actually do so on purpose. A report from 2020 also found that this reflex can help create interaction and bond between the infant and the adult. The Palmar Grasp Reflex develops roughly between 11-16 weeks in utero.
The Palmar Grasp Reflex should be integrated - not present - by no later than six months of age - the age when an infant begins to intentionally grasp objects.
Some potential symptoms of a retained Palmar Grasp Reflex in infants and older children are:
Delayed fine motor skills - poor grasp on objects
Challenges with handwriting
Challenges with self-care such as self-feeding and dressing
Potential challenges with speech
Tactile hypersensitivity
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The ATNR has been associated with assisting during the birthing process as well as it also facilitates the kicks felt in utero. Movement of the head to one side causes movement of the arms and legs and therefore helps to build muscle tone, skills on each side of the body, and hand-eye coordination. The ATNR develops at around 18 weeks in utero.
The ATNR should be integrated - not present - by no later than nine months of age.
Some potential symptoms of a retained ATNR in toddlers and children are:
Challenges with crawling
Poor handwriting
Challenges with visual tracking
Poor establishment of hand dominance after age 7
Consistent left / right confusion after age 8
Challenges with age-appropriate gross motor skills such as skipping
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The STNR is directly related to the TLR - because the STNR assists the infant with moving from prone (laying on belly) into quad (on all 4s - pre crawling position), it additionally assists with integrating the TLR. According to a report from 2020, the STNR develops between 6-9 months after birth.
The STNR should be integrated - not present - by 9-11 months of age (a very short life span compared to some of the other Primitive Reflexes).
Some potential symptoms of a retained STNR in toddlers and children are:
Challenges with crawling
Poor posture, low muscle tone
W-sitting
Clumsiness
Poor sustained attention
Challenges with reading and writing
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The Spinal Galant Reflex is associated with assisting during a vaginal birth, along with the ATNR, according to one research study.
In infants, stimuli provided to the lower back will produce movement of the spine and hip away from the stimuli. Therefore during the birthing process, contractions stimulate this reflex to help the baby move through the birth canal. The Spinal Galant Reflex develops around 20 weeks in utero.
The Spinal Galant Reflex should be integrated - not present - by around six months of age.
Some potential symptoms with a retained Spinal Galant Reflex in infants and children are:
Challenges with developmental milestones such as rolling
Challenges with natural gain - can have an effect on developing scoliosis
Challenges with focus, attention, and sitting still (ADHD symptoms)
Bedwetting beyond the age of 5 or 6 years
Tactile hypersensitivity, specifically with clothing
IMPACT OF RETAINED REFLEXES IN CHILDREN
Retained reflexes can significantly impact a child's development, affecting motor skills, coordination, and learning abilities. Understanding these impacts is crucial for identifying developmental delays and implementing interventions.
DEVELOPMENTAL ISSUES
Retained primitive reflexes can lead to various developmental issues in children. Typically integrated into mature movements as a child grows, these automatic reflexes can interfere with developing proper motor control and coordination if they persist beyond the expected age.
Some potential issues include:
Poor Motor Coordination: Difficulty with activities that require fine and gross motor skills, such as writing, cutting with scissors, or participating in sports.
Balance and Posture Problems: Challenges in maintaining balance and proper posture, leading to clumsiness and frequent falls.
Learning Difficulties: Struggles with reading, writing, and other academic skills due to the impact on visual tracking, eye-hand coordination, and concentration.
Behavioral Issues: Increased frustration, anxiety, and behavioral problems as a result of the difficulties in performing tasks that are easy for their peers.
Sensory Processing Disorders: Over-sensitivity or under-sensitivity to sensory stimuli, which can affect a child's ability to process and respond appropriately to sensory information.
Delayed Developmental Milestones: Slower achievement of milestones such as crawling, walking, and talking, which can impact overall development.