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The author, age 2, and (arguably) typically developing, uses two hands to attack a difficult job.

Within the first few minutes of my observation, one thing that becomes instantly apparent amongst children referred for Occupational Therapy (OT), are differences in bilateral integration and sequencing, reluctance to cross midline, and poor midline weight distribution and balance.

Bilateral integration is the coordination of right and left sides of the body. Children with differences in bilateral integration have difficulty performing tasks with two hands, especially when the hands are doing different things. Older children may have persistent difficulty judging left and right sides. They may master routine tasks (like shoelaces) but struggle anew when a task is unfamiliar. Organized ball sports are especially difficult, and older children may gravitate towards running or swimming, which rely on repetitive timed tasks instead of novel, strategic movements.

The brain is designed to specialize between right and left hemispheres. Generally, amid a few exceptions, the right hemisphere is responsible for left-side function, and the left hemisphere, for right. Certain areas of the brain, are specified for a particular job. If the left and right halves of the brain are not communicating well, the brain being a flexible, get-the-job-done organ begins to develop work-arounds.

One common work-around I see in young pre-writing children is late emergence of hand-dominance in one-handed activities. By the time a child enters school, hand dominance is typically established. It is generally emerging in the 4s and visible in the 5s. With children this age for whom bilateral integration may be an issue, they may pick up a crayon from their right side and use it in their right hand, then pick up a crayon from their left side and use it with their left hand. They are neither adjusting their grip (the grip is not consistent in either hand), nor using both hands together to pick up the tool and position it in their preferred hand.

In A. Jean Ayers, Ph.D., 25th Anniversary Edition of the book Sensory Integration and the Child: Understanding Hidden Sensory Challenges, describes it as thus, “The child develops similar skills with each hand and each cerebral hemisphere. Instead of using just one hand for fine motor work such as writing or using tools, he tends to use his right hand on the right side of the body and his left hand on his left. He may be considered ambidextrous, but actually he is not especially skilled with either hand. Or he may become left-handed while genetically, he is meant to be-right handed. Meanwhile, inside his brain, both of his cerebral hemispheres are doing similar things instead of specializing for greater overall efficiency.”

Ambidexterity is defined as:

able to use both hands equally well;

1: Using both hands with equal ease;

2: unusually skillful: versatile.

Thus, I am always alerted when I hear use of the word “ambidextrous” about a child (often said with some pride, or implying creativity or flexibility) that bilateral integration may be a concern. After observation, I find it is actually being used to describe indiscriminate use of either hand in an activity, though as Dr. Ayres described it, not necessarily with skill, which may in fact be the reason for the referral.

Another example of bilateral integration challenges may be in observed over-dominance, or the near neglect of the non-dominant side. If a child struggles and struggles to do a job, but doesn’t automatically recruit the other hand to help out, bilateral integration may be the reason why.   You should be seeing both hands working together on a hard job. Children with specific challenges in bilateral integration overly struggle with one hand and rarely/never use helper hand to get the job done, or require cues to use their other hand. (In handwriting referrals I receive, school-aged children are very commonly under-utilizing helper hand, and do not automatically even bring it up to the table. This is generally not a new pattern or behavior, was likely seen at younger ages, but was not yet a functional concern until handwriting was identified by parent or teacher as an issue.)

What to Observe?

Toddler/Pre-School Aged:

  • Playing with dough, your young child will be using both hands. They will readily choose and use a rolling pin with two hands, or pull, stretch, and wring dough between hands. They are passing the dough back and forth between hands.
  • In the sandbox, two hands will be working and playing, but not necessarily on the same thing. One hand will scoop and fill, while one hand is reaching or grasping.
  • They already use helper hand to steady their work—i.e. one hand holds the cup, and one hand fills it. One hand holds the jack-in-the-box, and one hand turns the crank. One hand holds the base, one hand lifts the lid.

Kinder/Grade School Aged:

  • Hand dominance should be apparent or emerging-apparent. Work quality should be significantly better using the dominant hand. Helper hand keeps work steady.
  • A child will pick up a tool with his dominant hand, or move it into his dominant hand, no matter where it sits on the table. Grip is consistent.
  • The non-dominant hand is a useful helper now, and can learn to perform assistive jobs, or complex jobs, to support the dominant hand (buttoning, zipping, shoe-tying).

Why is it Important?

As noted above, bilateral integration deficits are the result of reduced specialization in the brain with poor communication between left and right hemispheres. Like many sensory processing markers, it shows us on the outside what is happening neurologically on the inside. Bilateral integration is linked to reading, visual tracking, balance, dexterity, posture, coordination, work quality, and executive functioning/organization.

If you have concerns about the bilateral skills of your child, or if he/she seems “ambidextrous,” but with poor work quality or efficiency, an occupational therapist may be a good fit on your child’s development team.