Crossing Midline: The Imaginary Line Between Right and Left
Did you know that we all have an imaginary line running through the middle of our bodies?! It’s true! There are two sides of the body and in order for both sides to work together they must cross this imaginary line. Without the ability to cross midline, you would not be able to shake someone’s hand, read from left to right, write letters using your dominant hand, or even tie your own shoes using two hands at once!! Who knew?!
Crossing midline is the ability to move ones hands, feet, and eyes not only together, but across and to the other side of the body. Crossing midline requires the involvement of many skills including: body awareness, hand-eye coordination, muscular strength, and most importantly brain communication. Crossing midline builds new pathways in the brain which are building blocks for the development of additional complex motor and cognitive skills such as reading, writing, self-care tasks, and physical activity.
For most adults, crossing midline seems like something that just comes naturally. It’s not something you had to be taught, like reading and writing. However, crossing midline can be difficult for some children and can contribute to delays in development. Therefore, increasing the awareness of crossing midline delays and incorporating activities that promote crossing midline in your child’s natural environment are not only important, but may teach your child how to use both sides so they can grow, think, learn, and move their bodies effectively!
How do I know if my child has an issue crossing midline?
By the age of 3 or 4 years old, a child should be able to use both sides of their body effectively. Children who have difficulty crossing midline often have difficulties completing daily activities that involve “cross-lateral motions”. Difficulty crossing midline may be seen as:
– Difficulty using both hands to complete self care skills such as brushing your hair or difficulty putting on a jacket
– Difficulty with reading, writing, drawing, and cutting
– Difficulty coordinating eating utensils
– Difficulty with gross motor skills such as catching and throwing a ball
– Difficulty visually scanning to all directions
How crossing the midline affects life skills:
When a child has difficulties crossing the midline, it can affect their ability to read. While the child is moving their eyes across the page, their eyes may stop in the middle and frequently lose their place. It also affects handwriting since a child must cross the midline in order to write from left to right; the child may need to stop in the middle of the page to switch hands. Many self-care and daily living skills require crossing the midline as well (such as putting on socks/shoes and brushing teeth). Lastly, the inability to cross midline impacts eating. Children may have trouble properly moving food around in order to chew and swallow.
Children who do not cross the midline often do not develop a hand dominance (appearing to be ambidextrous), which should be determined by age 5. Children will be observed using both hands during drawing, eating, coloring, and throwing; however, if this pattern continues then the child may actually end up with two unskilled hands in the process. Children who do not cross midline often show symptoms including: poor fine motor control (immature pencil grasp & manipulation skills), poor bilateral coordination (catching a ball, cutting skills), poor upper/lower body coordination (jumping jacks, riding a bike), and poor right/left discrimination.
What you can do to help!
To help with development of crossing the midline, provide children with a variety of two-handed (bilateral) activities. Try some of the following activities to build pathways in the brain that will help the child to develop the ability to cross midline, improve coordination, and increase overall functional performance on a daily basis.
a. Pop bubbles with only one hand (they will have to reach across their body to pop the bubbles
b. floating on the opposite side).
c. Reach for bean bags, balls, stuffed animals, or other objects across midline, then throwing at a target.
d. Draw large figure eights (the infinity sign or an 8 turned on its side) on paper, on the floor with a finger, in the air with a finger, or drive a matchbox car around a figure eight pattern.
e. Let the child play with sand, scooping sand from one side of the body and putting it into a bucket on the opposite side of the body without switching hands.
f. Let the child pretend to drive a car with a ball in his/her hands to use as a steering wheel and encourage the crossing of his/her arms as he/she turns the ‘steering wheel’.
g. Play flashlight tag. In a dimmed room, lie on your backs and have the child follow your flashlight beam projected on the wall with his own flashlight.
h. Touch the opposite elbow and knee.
i. Cross one foot over the other while walking sideways.
j. Windmills-stand with feet spread apart and arms extended out to the sides. Bend over at waist and tap right hand to left foot. Stand back up and then bend and tap left hand to right foot.
k. Wash the car and make sure the arms cross midline while scrubbing.
If you have further questions regarding crossing the midline, please refer to your occupational therapist at Pediatric Therapy Center. Be creative and have fun!
Sara Welniak, MOT, OTR/L and Heather Smith, OTS