All day long, we perform tasks that are second-nature to us – we don’t think twice about them! Just this morning, you probably made breakfast, got showered and dressed, tied your shoelaces, drove a car, sat at a desk and wrote a note.
What do all these tasks have in common?
They require the use of all four of our limbs!
It is because of well-integrated positional primitive reflexes that we can do these tasks without much thought (except for making food, which requires a lot of thought for me).
There are 3 positional primitive reflexes:
- The Asymmetrical Tonic Neck Reflex (ATNR)
- The Symmetrical Tonic Neck Reflex (STNR)
- The Tonic Labyrinthine Reflex (TLR).
All three of these reflexes are technically activated by the position of the head. The ATNR and STNR, specifically, are activated by the position of the neck. The TLR is vestibular in origin as it is affected by head position and activated by the labyrinthine apparatus of the ear.
ATNR (Asymmetrical Tonic Neck Reflex)
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ou’ve probably seen the ATNR reflex without even knowing it! If you’ve ever seen a baby laying on their back looking like they are about to start a fencing match, you have seen ATNR. This is a reflex that emerges at 18 weeks gestation and should be inhibited by the time the child is 6 months old. It is purposeful in utero because it facilitates movement (a kicking motion), develops muscle tone, and provides vestibular stimulation. As it provides continuous motion, a balance mechanism is stimulated and neural connections increase. ATNR is also crucial in the development of eye-hand coordination.
Signs of a retained ATNR reflex:
- Difficulty crossing midline (i.e. tasks that require two hands working together).
- Failure to establish a preferred/dominant hand.
- Eye movements will also be affected. If following an object visually (with head remaining still) as it is moved slowly in front of him on a horizontally there will be a slight jerk/twitch/jump of the eyes as the object is moved from one side of his nose to the other. This same hesitancy will also prevent fluency when he later tries to read.
- Poor balance
- Poor ability to perform smooth cross-patterned movements (i.e. marching while hitting right hand to left leg and vice versa)
- Poor visual perceptual skills
- Poor handwriting
- Poor expression of ideas
STNR (Symmetrical Tonic Neck Reflex)
The STNR does not last long as it emerges when the child is 6-9 months old and should be inhibited by 9-11 months old. But though it is short lived, it is critical during the crawling stage. STNR effectively divides the body in half at the horizontal midline. Children who retain the STNR rarely crawl on hands and knees correctly (there may have been compensatory strategies).
Crawling is one of the most important movement patterns in the prolonged process of teaching the eyes to cross the midline. Crawling facilitates a connection – for the first time – of the vestibular, proprioceptive, and visual systems. Without this integration there can be a poor development of balance and poor space and depth perception.
Signs of a retained STNR reflex:
- Poor posture
- Tendency to “slump” when sitting
- An ape-like walk
- Sitting with legs in a “W” position
- Poor hand-eye coordination
- Messy eating
- Clumsiness
- Inability of a child to change focus easily from blackboard to desk
- Slowness during copying tasks
- Difficulty learning to swim or unsynchronized movements when swimming above the water
- Can affect attention
TLR (Tonic Labyrinthine Reflex)
The TLR can be divided into two categories: TLR Forward (emerges in utero and integrates by 4 months) and TLR Backward (emerges at birth and integrates gradually between 6 weeks and 3 years old). The TLR is elicited by movements of head forwards or backwards, above or below the level of the spine. Head movement should be the prime initiator of early movement, tone, and balance. TLR affects the distribution of muscle tone throughout the body, helping the newborn “straighten out.” Balance, muscle tone (balance between flexor and extensor muscles), and proprioception are all trained during this process.
Signs of a retained Forward TLR include:
- Poor posture
- Hypotonus (weak muscle tone)
- Vestibular-related problems
- Poor sense of balance
- Propensity to get car sick
- Dislike of sporting activities, PE classes, running, etc.
- Oculomotor dysfunctions
- Visual-perceptual difficulties
- Spatial problems
- Poor sequencing skills
- Poor sense of time.
Signs of a retained Backward TLR include:
- Poor posture
- Tendency to walk on toes
- Poor balance and coordination
- Stiff/jerky movements
- Vestibular related problems
- Poor sense of balance
- Motion sickness
- Oculomotor dysfunction
- Visual-perceptual difficulties
- Visual spatial perception problems
- Poor sequencing skills
- Poor organization skills
Do any of these symptoms sound familiar? Have you seen them in your child? A child you know? Maybe in yourself?!
Our bodies are amazing creations. When they don’t function as they were designed to function, however, a lot of different challenges arise. What is truly amazing, though, is that God has designed us in such a way that – when these challenges arise – we can re-teach our bodies and re-wire our brains so that we can perform at our highest potential!
If you are concerned that your child may have a retained primitive reflex, please call me to set an appointment for an evaluation!
Just one more post is left in our Primitive Reflex Series! Stay tuned!
Blessings,
-Christiana Cooper, OTR/L
References:
Goddard S. Reflexes, Learning, and Behavior: A Window Into the Child’s Mind. Fern Ridge Pres. 2005., ed 2.
Kaleidoscope Occupational Therapy 