I answer this question from parents about once a month, on average. Here is the better question: Is my child developing age-appropriate grasp?
The statistics are against your child being ambidextrous: only about 1% of people are truly ambidextrous. Being able to hit a ball equally well with either arm is valued on a team, but when they sit down for supper, switch hitters probably don’t use both hands equally to twirl their spaghetti. But….children who have poor core stability often do not reach across the center of their body and switch hands to reach what they need. Children who have motor planning or strength/stability issues will switch hands if the become fatigued or frustrated. None of these children are truly ambidextrous. They are compensating for delays and deficits.
Studies I have read on the development of normal hand dominance suggests that some children are seen as having emerging hand dominance (consistent and skilled use of one hand rather than the other) as early as 12 months. You know those kids; they pick up cereal bits with their thumb and index finger at 9 months and pop them into their mouths individually as if they were sitting at a bar with a bowl of peanuts and a beer! They delicately hand you the bit of string they found while crawling, and are already trying to unzip your purse. Those kids. It is more common to see emerging hand dominance in the 18-24 month range. Developmental issues often delay this progression, and issues such as cerebral palsy can result in a child whose neurology would be expressed as right-dominant requiring more left-dominance due to hemiplegia. That’s right: hand dominance is biological, not learned, and very likely inherited to some degree.
In my professional career, the greatest predictor of age-appropriate grasping skills has been not core stability or even muscle tone, but exposure and interest. I work with a child that is legally blind since birth, and his grasping skills are very delayed. His exposure is biologically limited. He cannot see what his fingertips are doing, and since he has some vision, he is not doing what totally blind children usually do. They increase their tactile exploration of objects because they don’t have any visual information, and in doing so, end up with generally good refined grasp and control. This child has slowly developed his skills with carefully chosen and strongly emphasized activities in therapy.
Low muscle tone makes it difficult for infants to develop effective opposition, the rotation and bending of the tip of the thumb opposite to the tip of the index finger. It is common to see opposition to the tip of the middle finger. The stability offered by that finger’s placement between two fingers at knuckle-level, plus less rotation needed, explain that quite clearly. Sadly, the middle finger doesn’t have the refined movement of the index finger, so control is lacking. They tend to use a fist for gripping toys, and often end up dropping or breaking their goldfish crackers. These kids often actively dislike using their hands in a skilled manner. “Read me a book or let me run around” rather than “Give me tiny snacks and beads to string”. If it is true pattern of avoidance and frustration, it isn’t simply a preference. It’s an issue.
How can parents support the development of hand skills at all ages?
- Infants under 12 months: Provide safe and desirable things to pick up. Bits of food that aren’t choking hazards. Toys with tags firmly sewn on. Toys with parts that spin and have textures to explore. Show your interest and delight in this exploration.
- Toddlers: Even more opportunities and enthusiasm. Let them scribble on magnetic boards, use food as fingerpaint, and introduce utensils as early as safe. Us lots of containers that need to be opened, closed and held for filling and emptying. Check out Easy Ways To Build Bilateral Hand Coordination for Writing for more ideas.
- Preschoolers: Don’t tape down that paper! Teach the use of the “helper hand” Better Posture and More Legible Writing With A “Helper Hand” if it isn’t being used, and double-down on toys that require both hands.
What are your best methods for refining grasp and dominance? All you teachers, therapists and parents out there, please comment and add your ideas!