You may have seen Baby hangin’ out on his belly or back with one hand at his mouth and the other lengthened behind his head. It’s a reflex! Good ole–what we call–“Hand To Mouth.”
Many people are familiar with its mirror: Asymmetrical Tonic Neck Reflex (ATNR). ATNR is easy to spot in the youngest babies: the notorious turning of head to one side, with the ‘back’ arm bent and the arm Baby is turned toward to lengthened. Legs are involved too, to varying degrees: the same-side leg will be bent or lengthened to match what that-side arm is doing.
Every reflex has an opposite and balancing reflex, and these two are an excellent example. In Hand To Mouth, the arm and leg bend more fully on the side the face 
is turned to. Hand To Mouth gives Baby access to his hand. This sounds needless of mentioning; but it’s important when you have such a strong reflex that makes your hand go away from your mouth (ATNR)! Just think, if that reflex did not have an opposite! “Mouthing” his hand can bring Baby a sense of calm, give his brain awareness of all his fingers, build hand-eye coordination, and lay a foundation for feeding himself.
Do It Yourself For Understanding
Hand To Mouth:
- Turn your head to one side.
- Bring that same-side hand to your mouth and bend that leg up. Keep the other arm and leg lengthened.
- That’s the position; now do it as a movement.
ATNR:
- Turn your head to one side.
- Straighten the arm and leg on the side you’re looking toward; bend the other arm and leg.
- That’s the position; now do it as a movement. You may feel a ‘magnetic’ pull into the position–that’s your body remembering the reflexive quality of ATNR!
Why This Fancies Noticing
Reflexes are the building blocks of movement. For a typically-progressing baby, reflexes are triggered naturally while responding to his environment, and a lot of them happen while lying on his tummy. What if you could continuously switch back and forth between Hand To Mouth and ATNR in movement?
ATNR + Hand-to-Mouth (+ a few others) = belly crawling! That is, along with belly-down stimulation of the floor to push against, plus motivation to reach mama or a toy!
© Elizabeth Parker 2011, All Rights Reserved (Links are welcome. If you’d like to share my post in your blog or materials, please ask permission.)
Much of my work comes from Infant Developmental Movement Education®, part of the Body-Mind Centering® Approach to Somatic Education, and Dr. Aletha Solter’s Aware Parenting. I am a certified Infant Developmental Movement Educator®, Body-Mind Centering® Practitioner, Feldenkrais® Practitioner, and Spiritual Counselor.