What is Motoric Separation of the Two Sides of the Hand?
A child is fumbling to manage the buttons on their sweater.
A little one is zipping up their coat and they have the zipper and coat clenched between their pinkie fingers and thumbs.
A Kindergarten student is learning to write letters on lines, but they’ve got the pencil in a clenched grasp, using their whole hand.
All of these examples indicate a fine motor need to work on motoric separation of the two sides of the hand.
In-hand manipulation activities are a great way to boost fine motor skills needed for tasks like managing clothing fasteners, using a pencil when writing, manipulating items like coins or beads, and more.
You might be thinking, “Say what? My hand has two sides?”
Yep! You can imagine a line drawn from your wrist directly down the middle of your hand and between your ring finger and middle finger, separating the precision side of the hand (thumb, pointer finger, and middle finger) with the power side of your hand (pinkie finger and ring finger). These two sides work together in skilled activities with precision and power grasp in functional activities.
Try this fun activity to work on separating the sides of the hand, using sponges you might have in your kitchen right now.
Motoric Separation of the Two Sides of the Hand
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Refinement of fine motor skills like pencil grasp, manipulation of very small items, and managing zippers, shoe laces, and buttons with the precision half of the hand (the radial side) happens when the power half (the ulnar side) is stabilized. A functional fine motor grasp and manipulation of objects is more accurate when the ring and pinkie fingers are flexed (bent) into the palm.
An alternative to a flexed position of the ring and pinkie fingers are when theses two digits are fully extended out and stretched out away from the hand (abducted). This positioning stabilizes the MCP arch and allows for control of the pointer and middle fingers.
Separation of the two sides of the hand allow for more precise use of the thumb.
How does motoric separation of the hands develop?
Hand separation starts when a baby bears weight through their arm and ulnar side of the hand while carrying a toy in the radial side. This simple activity developmentally lengthens the muscles of the ulnar side.
Simple activity to work on separation of the two sides of the hand:
We used star beads that we received from www.craftprojectideas.com. You can find them here.
I placed the beads into a shallow basket and asked my kids to grab only one color that they liked best. They then tried to hold as many of that one color in their hand while picking up more beads. When they couldn’t possibly hold anymore beads in their chubby little cute hands, I showed them how to drop them into a small cup one at a time, while counting how many beads they had. This type of activity is a version of in-hand manipulation called translation.
More simple ways to work on motoric separation of the sides of the hand
Roll play dough into small balls
Squeeze a spray bottle with the pointer and middle fingers
Pick up small items and “squirrel them away” into the hands: mini marshmallows, cereal, small beads, coins, waterbeads. (This is also called translation toward the palm.)
Release the items (This is also called translation away from the palm.) Place coins into a piggy bank or beads into a cup.
Hold a cotton ball in the palm with the ring and middle fingers while coloring, writing, or cutting with scissors.