So what’s all the Fuss about Crossing the Midline?

Children are most often referred for Occupational Therapy for fine motor problems, poor pencil grip, weak pencil control, poor attention and concentration difficulties, chewing on their sleeves, chewing on their pencils, biting other children, being fussy eaters… the list goes on! They are also sent for OT because they don’t cross their body midline. What exactly does this mean?

The simple answer is that the child does not easily use his right hand to reach over to the left side to do things and vice versa, and he does not comfortably or automatically take his left hand over to the right side of the table to pick up things or to use a tool. So what’s the fuss you might think? Surely the child is simply moving in a more economical fashion! Using the right hand on the right side surely beats taking the left hand all the way across to the right side? Wrong!

Our bodies were designed to twist or to rotate about a central pivot. Think of a golfer swinging a club. She can hit that ball much further if she rotates her hips, her trunk, and then her shoulders. Similarly, rotation about a steady midline helps the cricketer to hit the ball further. A child sitting at a table and writing is also more stable when he can rotate about a central pivot. If you are finding it difficult to imagine this, just imagine three marshmallows with a skewer stuck through the middle (yum!). The bottom marshmallow would be the hips, the middle the shoulders, and the top the head. They can, and should, all move independently and in synchrony of each other. When they do not, body rotation becomes awkward and difficult.

How does this look in a five year old that is not able to cross his midline. Since he struggles to reach comfortably across with his right hand to colour in the car on left hand side of his page, he will either shift the page across so that it is directly in front of his right hand (so he has avoided crossing the midline), or, he will shuffle his bum to the left side of his chair so that his right hand is now exactly where he needs to colour in. Otherwise, he may even swop the crayon from his right hand into his left hand! Since he doesn’t only need to colour in the pretty picture on the left side, he will make lots and lots of body shifts or paper shifts in order to bring the picture and his hand into the correct alignment. This is pretty tiring and he will likely not complete the job! Otherwise, he will take a whole lot longer to get the job done than if he had been able to effortlessly cross his body midline.

Midline crossing difficulties sometimes accompany difficulties in establishing handedness, and difficulties with visual perception.

Midline crossing actually starts to develop somewhere around three months of age when the baby first starts to roll over from tummy to back, rolls over onto his side and wriggles about using good rotation movement patterns. Think of the movement of a salamander or a lizard, as it shortens one side of its body while the other side stretches and lengthens. It continues later, when the baby twists up from lying on his tummy to push himself up into sitting. Still more healthy rotation develops when the baby is sitting, and he puts his right hand to the side to support himself while he stretches across with his left hand retrieve a toy that has rolled away to the right. A baby who actively uses his body to move through healthy rotation patterns sets the tone for good midline crossing, which is expected to be in place around five years of age.

 We can help children to stretch the muscles for rotation by encouraging them to twist at the waist. Here are a couple of simple helpful exercises…

  • “Twisties”: Stand up and face the front and twist around to try and look behind you with your arms swinging loosely at your sides.
  • Sit on your bottom on the floor with your legs out straight in front of you. Reach round to either side to reach for various objects, such as puzzle pieces or Lego pieces, or simply twist to try to look behind you to each side.
  • Sit with your legs apart and take your hand to the opposite foot, and vice versa.
  • “Windmill”: Stand with your legs apart and swing your right arm down to your left foot, and vice versa.
  • Sit on the floor with your legs stretched out in front of you. Wriggle forwards on your bottom, lifting each side of your bottom in turn as you “walk” forwards on your bottom!

These are just a few exercises to get you started. Have Fun!

 

Midline crossing is often a part of more complex difficulty with movement patterns. You may need to consult with an OT or a physio who has training in Neuro Developmental Therapy.