Why do children need to cross the midline? The midline is an imaginary line that goes directly down the center of the body from the top of the head and between the eyes and down through the belly button. This creates the right side of the body and the left side of the body. Crossing the midline is the ability to use the left hand over on the right side of the body or the right hand on the left. Imagine putting your right hand out to shake someone else’s hand. You reach your hand across the center of your body to take their hand. This is crossing the midline.
Young children are working on this physical skill. It is not easy for all of them. When you put your hand out to shake a three-year old’s hand, she might stick her left hand out to meet your right, rather than crossing over the center. It is hard for children to kick their legs across the midline, so they kick them straight out in front. You may observe them drawing on one side (the left or right, not front or back) of the paper only.
Crossing the midline allows for children to become “bilateral” or to have the ability to use both sides of the body simultaneously. It creates neural pathways that travel from one hemisphere of the brain to the other. It allows us to scratch one elbow with the opposite hand and without it we couldn’t play the piano. It also supports “handedness” as the child begins to prefer one hand over the other. This become increasingly important as children begin developing the fine motor control needed for writing. Children who struggle with crossing the midline may have trouble learning to read, as their eyes can’t travel all the way across the page. They may struggle with writing, and also may appear ambidextrous (which may sound like a good thing, but can cause problems later.)
There are loads of activities that can help children cross the midline. Gross motor games like kicking balls, playing catch, and Follow the Leader are good choices especially if the children are encouraged to catch with the “other hand” or to follow the leader when the leader is touching their left toes with their right hand, etc.
As someone who practices a lot of yoga, body awareness is very important. I know that a lot of teachers of young children spend time working on “body parts” i.e., fingers, toes, legs, and head. How about adding “body areas” to that as well?
Work with children on knowing where their “front body” is and where their “back body” is. See if they can identify their “side body” and then make sure they know they have two of them. There is the upper half of the body, from the waist up, and the lower half of the body, from the waist down. All of these body areas will not only help children cross the midline as they begin to identify their sides, but will increase their spatial awareness. Remember, one of the earliest math skills children develop is spatial awareness in terms of where they are and others are in relation to one another.