Asymmetrical Tonic Neck Reflex (ATNR)
In utero, the Asymmetrical Tonic Neck Reflex helps facilitate kicking movements of the fetus felt by the mother. When fully emerged in utero, the ATNR supports the fetus in twisting and turning down the birth canal. As the ATNR integrates, the movements of the infant on the stomach and the back help to train binocular vision (the cooperation of both eyes) and the ability to track moving objects with his eyes. A nonintegrated ATNR beyond four to six months can interfere with other developmental motor abilities, such as rolling over, commando-style tummy crawling, and crawling on all fours. Crawling in fluent cross-patterned movements is more complicated when the ATNR reflex is not integrated.
In school, the ATNR plays a significant role in the learning process and in creating more hemispheric brain dominance. It helps to establish cross lateral motor coordination across the physical midline, as well as, active coordination of the visual and auditory systems. Dr. Harald Blomberg (2011) explains that good reading and reading comprehension ability is “dependent on a working exchange of information between the hemispheres through the corpus callosum” (p. 184). The ATNR is also important for writing, as it assists with the motors skills of the arms, shoulders and neck in order for fine motor skills to be efficient.
Some symptoms of a nonintegrated Asymmetrical Tonic Neck Reflex
- Difficulty crawling in cross-patterned movements
- One sided (robot like movement) rather than cross lateral walking
- Difficulty with eye tracking, eye-hand coordination
- Difficulty with reading, writing, listening and comprehension; dyslexia
- Poor handwriting and difficulty fluently expressing ideas when writing
- Inefficient motor skills of the arms, shoulders and neck (e.g. riding a bike)
- Mixed or confused handedness is common
- Insecure balance