Comprehensive Guide to Primitive Reflex Development and Inhibition

Moro Reflex

• Description and Mechanism

  • Commonly referred to as the ‐fight or flight‐ response, the Moro reflex involves the activation of the sympathetic nervous system.

  • This reflex is triggered by any kind of sudden and unexpected occurrence.

  • The movement sequence consists of the arms and legs moving outwards accompanied by a quick inhalation, followed by a momentary freeze. Subsequently, the arms and legs tuck back in as the child exhales.

  • This physical response may be accompanied by an outburst of cries.

• Developmental Timeline

  • Begins to develop: $9$ weeks in utero.

  • Age inhibited: $2-4$ months of life.

• Signs and Symptoms of Retention

  • Hypersensitivity and reactivity.

  • Poor impulse control.

  • Vestibular-related difficulties, including motion sickness and poor coordination (particularly noticeable during ball games).

  • Physical timidity.

  • Oculomotor and visual perception problems.

  • Poor pupillary control, which results in sensitivity to light; this is likely caused by adrenal fatigue.

  • Poor auditory discrimination.

  • A marked dislike of change or surprise.

Palmar Reflex

• Description and Mechanism

  • The Palmar reflex is elicited by light touch or pressure in the palm of the hand, which causes the fingers to close.

• Developmental Timeline

  • Begins to develop: $11$ weeks in utero.

  • Age inhibited: $2-3$ months of life.

• Signs and Symptoms of Retention

  • Poor manual dexterity and fine motor skills.

  • Poor writing skills, characteristically involving messy handwriting or pressing too hard on the page.

  • Speech difficulties, resulting from the hand-and-mouth relationship governed by the Babkin response.

Asymmetrical Tonic Neck Reflex (ATNR)

• Description and Mechanism

  • Movement of the baby’s head to one side results in the extension of the arm and leg on the side the head is turned toward, while the limbs on the opposite side of the body bend.

  • The ATNR is essential for assisting in a vaginal birth.

• Developmental Timeline

  • Begins to develop: $18$ weeks in utero.

  • Age inhibited: Approximately $6$ months of life.

• Signs and Symptoms of Retention

  • Affected balance resulting from head movement to either side.

  • Homolateral movements (moving the arm and leg on the same side together) instead of the normal cross-lateral movements during walking, marching, or skipping.

  • Difficulty crossing the body's mid-line.

  • Poor ocular pursuit movements (eye tracking).

  • Difficulties with hand-eye coordination.

  • Poor handwriting and difficulties with the expression of ideas on paper.

Rooting Reflex (Grasp Reflex)

• Description and Mechanism

  • This is a searching, sucking, and swallowing reflex.

  • A light touch of the cheek or stimulation of the edge of the mouth causes the baby to turn the head toward the stimulus and open the mouth in preparation for sucking.

• Developmental Timeline

  • Begins to develop: $24-28$ weeks in utero.

  • Age inhibited: $3-4$ months of life.

• Signs and Symptoms of Retention

  • Hypersensitivity around the lips and mouth.

  • The tongue may remain too far forward in the mouth, making the swallowing and chewing of certain foods difficult.

  • Speech and articulation problems.

  • Poor manual dexterity related to the Babkin response.

Spinal Galant Reflex

• Description and Mechanism

  • The Spinal Galant reflex assists in the birthing process.

  • While the child is in the prone position, stimulation of the back on one side of the spine results in hip flexion (rotation) to $45$ degrees towards the side of the stimulus.

• Developmental Timeline

  • Begins to develop: $20$ weeks in utero.

  • Age inhibited: $3-9$ months of life.

• Signs and Symptoms of Retention

  • Fidgeting.

  • Bedwetting.

  • Poor concentration.

  • Poor short-term memory.

  • Unilateral or bilateral postural issues.

Tonic Labyrinthine Reflex (TLR)

• Description and Mechanism

  • The TLR consists of two parts: flexion (forward) and extension (backwards).

  • It serves as the basis for head management and postural stability using major muscle groups.

  • The reflex is elicited by moving the head forward (flexion) or backwards (extension), either above or below the level of the spine.

  • The TLR exerts a tonic influence on the distribution of muscle tone throughout the body, helping the baby to ‐straighten out‐ from the flexed position held in the womb.

  • Balance, muscle tone (the balance between flexor and extensor muscles), and proprioception are all trained through this process.

• Developmental Timeline

  • Flexion: Begins to develop in utero.

  • Extension: Present at birth.

  • Flexion inhibition: Approximately $4$ months of life.

  • Extension inhibition: Up to $3$ years old.

• Signs and Symptoms of Retention

  • Postural Issues: Flexion retention leads to a stooped posture, while extension retention causes walking on toes.

  • Muscle Tone (Hypotonus): Flexion retention manifests as weak muscle tone; extension retention manifests as stiff, jerky movements.

  • Vestibular Problems: Both flexion and extension retention cause a poor sense of balance and motion sickness.

  • Oculomotor Dysfunctions: Both types lead to visual-perceptual difficulties and spatial perception problems.

  • Sequencing: Both flexion and extension retention result in poor sequencing.

  • Specific Flexion Symptoms: Dislike of sporting activities and a poor sense of time.

  • Specific Extension Symptoms: Poor organizational skills.

Symmetrical Tonic Neck Reflex (STNR)

• Classification

  • The STNR is considered a ‐bridge‐ reflex between primitive and postural reflexes.

• Description and Mechanism

  • This reflex consists of two parts: flexion (forward) and extension (backwards).

  • When a child is prone and resting on all four limbs, flexion of the head causes the arms to bend and the legs to extend.

  • Conversely, head extension causes the legs to flex and the arms to straighten.

  • The reflex helps the child defy gravity by getting up off the floor onto the hands and knees from a prone position.

  • It assists in inhibiting the Tonic Labyrinthine Reflex (TLR) and forms the bridge to the next stage of development.

• Developmental Timeline

  • Emergence (both flexion and extension): $6-9$ months of life.

  • Inhibition (both flexion and extension): $9-11$ months of life.

• Signs and Symptoms of Retention

  • Poor posture.

  • A tendency to ‐slump‐ when sitting, especially at a desk or table.

  • Simian (ape-like) walk.

  • Poor hand-eye coordination, such as difficulty copying from a board.

  • Inability to sit still and concentrate.

Landau Reflex

• Classification

  • The Landau reflex is considered a ‐bridge‐ reflex between primitive and postural reflexes.

• Description and Mechanism

  • Helps to inhibit the Tonic Labyrinthine Reflex (TLR) and assists in the bridge to the next development stage.

  • In the prone position, if the baby is suspended in the air with support under the stomach, the reflex engages extensor tone throughout the body.

  • Its primary function is to assist with posture development.

• Developmental Timeline

  • Emerges: $4-5$ months of life.

  • Inhibited: $3.5$ years of life.

• Signs and Symptoms of Retention

  • Negatively affects the development of balance and muscle tone in conditions that are rapidly changing.

  • Running with stiff, awkward movements.

  • Difficulty performing motor tasks such as hopping, skipping, and jumping.

Reference Material

• Melillo, R. (2009). Disconnected Kids. Penguin Group Inc.

• Goddard, S. (2005). Reflexes, Learning and Behaviour, A Window Into the Child’s Mind. Fern Ridge Press.

Reflexes: Overview and Types

• Definition: Reflexes are automatic responses to stimuli that are often crucial for survival and bodily function.

• Primitive vs. Postural Reflexes:

  • Primitive reflexes emerge early in life and are instinctual responses to stimuli.

  • Postural reflexes develop later, supporting voluntary movement and complex behavior.

Types of Primitive Reflexes

1. Moro Reflex: The child responds to sudden stimuli with stretching out the arms and legs and then tucking them back in.

2. Palmar Reflex: Triggered by touch on the palm, leading to finger closure.

3. Asymmetrical Tonic Neck Reflex (ATNR): Movement of the head causes corresponding limb extension and flexion.

4. Rooting Reflex: The baby turns its head and opens its mouth when the cheek is touched, preparing for feeding.

5. Spinal Galant Reflex: Stimulation of the spine on one side leads to hip flexion toward that side, aiding in birthing.

6. Tonic Labyrinthine Reflex (TLR): Influences head and body position relative to gravity.

7. Symmetrical Tonic Neck Reflex (STNR): Flexion and extension of the head alter limb positions.

8. Landau Reflex: Involves extension of the limbs when the baby is held in the air, aiding in posture development.

Importance of Reflexes

• Reflexes are critical for survival mechanisms in infants, facilitating essential functions such as feeding and locomotion.

• Retained primitive reflexes can impact motor skills, sensory integration, and behavioral responses as a child develops.