During play and activities a child may need to reach for an item that requires them to cross their midline. Crossing the midline may involve the arm or leg crossing their body from one side to the other, such as reaching with the right hand for an item on the left side. This is a diagonal pattern of movement and not a linear pattern. Individuals who do not cross their midline tend to reach with the hand that is on the same side as the object and then transfer it to the hand that will use it or they may turn at their waist, avoiding crossing their midline. When observing the latter, it initially appears to look as if the child is crossing, but upon closer observation, you can see that the arm does not draw a diagonal line.For example, when performing paper pencil activities, you may sometimes notice that the child may pick up the pencil with their left hand, but transfer it to the right hand as soon as the hand is at midline. They then continue with the activity on the right side of the paper.
Crossing the midline is important for smooth coordinated two-handed movements. The brain is “talking” to both sides of the body and understanding each and coordinating their actions to work together, and not as “individual” entities. When both sides of our body “understand” and are “aware” of each other, they can perform a vastly increased number of complex motor movements, especially ones in which one hand is performing one action differently from the other.
We perform multiple two-handed activities every day. In some activities one hand is acting as the stabilizer (such as holding the paper still while cutting/writing, or holding a container) while the other hand is performing an action (using the crayon/ scissors, or unscrewing ajar lid). Other times our hands may be performing the same motor movements (using 2 hands to hold a cloth while wiping the table or pushing a broom). In motor actions where each side is performing a different motor movement pattern, coordination and orchestrated planning in required for one’s brain to enable an individual to perform such actions. An example is playing “itsy bitsy spider going up the water spout” where each hand is rotating opposite of each other, or dressing a doll. If each side worked in isolation of each other, or the communication and understanding that there are two sides is interrupted, motor actions appear awkward and uncoordinated, and in some cases very difficult to execute.
Children with these issues tend to become, and rightfully so, frustrated, and avoid such activities. They may vocalize they can’t do the activity and push it away, or just not participate.
There many ways in which you can help facilitate crossing the midline. You may play a modified version of hot potato in which you pass the “potato” using both hands, but instead of turning at your waist you cross your arm in front of your body, or you may only pass with your right hand to the person on your left, again not turning at your waist.
You can also sit across from one another and sing songs (such as the camp fire or “patty cake” type songs) where each person reaches across, clapping hands with the same hand as the other person (your right hand to their right hand, then left hand to left hand). I also like to use some of the activities from Brain Gym. Brain Gym was developed by educator and reading specialist Paul E. Dennison and his wife, Gail E. Dennison. The theory behind the activities is to assist with developing better coordination between the individual’s eyes, ears, hands and whole body. They designed 26 different activities and you can find more information in your library, bookstore or using the internet.
You may also gently “block” the opposite hand, therefore preventing transferring of the object to the other hand. You can also guide a child using hand over hand assist through crossing their midline. Sometimes I find using quick, large movements works well. If I am playing with a child in a painting activity or using dot markers, I will have the child use both hands to hold the thick-handled paint brush or dot marker with my hands on top of theirs. I will use large movements, lifting the arms up, over and down crossing over their midline while making their splash/dot art. This can also be done while making hand print pictures or gluing on pieces of paper to make a collage.
Another activity may be setting up a train/car track using a horizontal figure eight path. With the child sitting facing the center of the track, have them use one hand (or both hands) to move the train/car around the track. Not only do these activities help the arms cross the midline, but they also help develop better eye scanning and scanning outside their shoulder range.