Relationship of Hand and Mouth in Development

Movement in the hand and mouth are connected developmentally.
Below are just a couple of the ways:

Many primitive reflexes help a baby use hands to
feed and later learn to talk. One of these early reflexes is Babkin Palmomental where when the babies palm is touched or stretched and the baby’s mouth opens. You will see this in elementary
classes when children are raising an open hand and some mouths are usually hanging open. Hand to Mouth is another developmental reflex related to the one above. If something is pressed into the palm of a toddler, it is raised to the opened mouth.

In our course you may remember that the motor
areas of the mouth and hand are very close together in the Upper Brain. Some people have trouble speaking if they can’t move their hands. Also movement of the hands activates the speech centers of the brain in the parietal lobes. Research that uncovered this relationship was explored by Shigeru Obayashi and his team in 2001.
If anyone doubts the above have them open their mouths and
hands widely and after 5 seconds tightly fist the hands and tightly purse the mouth for 5 seconds. Repeat 3 or 4 times. Now have them reverse the action. Open the mouth and clench the fist and open the hand and purse the mouth. This second pattern goes against the pattern and is usually harder to accomplish.
Of course later in life, most people can use the upper brain
of the cortex to override the lower automatic systems used in development. One
will still see the hand mouth relationship when showing an emotional reaction,
such as, surprise where both hands and mouth are open and anger where hands and mouths are clenched.
The relationship between the mouth and hand is very important in early development. So in atypical development the motor relationship between hand and mouth can be used to restore disrupted or traumatized development.

It's a Hand to Mouth Existence

The relationship in the brain between movement of the hand and movement of the mouth is well documented. Just think of places in the world where people can't speak without moving their hands. The sensory motor cortices (or cortex for the grammatically simple) have large and closely related areas dealing with the sensory intake and motor output of the hand and mouth. At the base of the left motor cortex is the Broca area in the frontal lobe for moving the mouth for speech, right next door is the hand to mouth coordination.

The Grasp Reflex and Babkin Palmomental Reflex are primary reflexes stored in the brain stem. Babkin activates by touch and stretch in the palm and the mouth opens and the mouth moves toward the hand. When I see children with writing issues I usually see a combination of these two reflexes. However handwriting includes more than just hand reflexes and can include differentiation of wrist, elbow and shoulders.

In talks with others in the field, some people combine Babkin and Hand to Mouth Reflexes. Some people combine all types of grasps into the Grasp Reflex. I didn't have much to say except all the relationships of the hand and mouth are complex. But then I had a new experience.

I rarely work with adults in reflex integration for many reasons; the main one being they are harder to deal with. However, a young adult came in to see me with the main issue being compulsive nail biting. I checked Babkin; I checked Grasp. They seemed OK. I was confused. I try a new tact. Maybe elbow bending is the issue with Hands Pulling. A bit retained, but not enough to answer the question. I decide to check Parachute Reflex. Oh my! The client fell toward the wall and caught himself with his hands in the Hanging Grasp. Then it hit me! Nail biting and Hanging Grasp are related if you add the Hand to Mouth Reflex. So Hanging Grasp is not Grasp and Babkin is not Hand to Mouth.

I came up with a handy isometric for both of these reflex and we'll see how these work for nail biters and kids who still put stuff in the mouth.