Asymmetrical Tonic Neck Reflex

The asymmetrical tonic neck reflex is activated as a result of turning the head to one side. As the head is turned, the arm and leg on the same side will extend, while the opposite limbs bend. The reflex should be inhibited by six months of age in the waking state.

If the asymmetrical tonic neck reflex remains active in a child at a later age, it can affect:

  • Hand-eye coordination – difficulties such as ability to control the arm and hand when writing.
  • Ability to cross the vertical midline. For example, a right-handed child may find it difficult to write on the left side of the page.
  • Discrepancy between oral and written performance.
  • Development of lateral eye movements, such as visual tracking, which is necessary for reading and writing.
  • Control of automatic balance.
  • Bilateral integration – differentiated and integrated use of the two sides of the body.
  • Continued cross laterality or ambiguity of laterality above eight years of age.