Bilateral integration is the ability to use the two sides of the body in a coordinated way, for instance when walking your left leg and right leg need to work together in order in for you to move forward. Crossing the midline is an important element of Bilateral integration. Imagine for a moment an invisible line running down the middle of your body, literally from the top of your head down to between the big toes of your left and right feet. Crossing the midline means that you are able to cross one side of your body over this imaginary line to work on the other side of the body.
We use this ability everyday, for instance when we want to draw a horisontal line across a page or when we need to reach out to a foot with both our arms to put a sock on. Some children find it difficult to do this – they might start drawing a horistontal line from the left with their left hand and then swap the pencil to their right hand when they come to the middle so that the right hand can continue drawing the line to the right side. Sometimes, children may also shift in their seat so that their entire body rotates to one side to avoid having to cross an arm or hand across the middle of the body.
Difficulties with crossing the midline may result in children not establishing hand dominance, not being able to work horisontally across a page from left to right or not being able to read fluently across a page from left to right as the eyes do not work together to track words across the page.
Here are some ways in which you can encourage your child to cross the midline:
- While your child is lying down, playing with dolls or cars on the carpet encourage him to lean his head on one hand – this way he will have to reach across his body as he plays with the toys.
- Stick a big piece of cardboard or butcher’s paper onto a wall and have your child draw big “lazy eights” (a figure 8 lying horisontally on its side) on the paper.
- Play games like Twister or Simon says (say things like “put your left hand on your right ear”, etc) or have our child sit in a circle with some friends and have the children pass a big ball along in the circle, play patty cake or crawl like a baby.
- Take out some old pots and pans and have your child use them as a drum set – he won’t even realise that he’s crossing the midline as he bangs away.
- Have your child sit cross-legged on the floor