Is your baby using one hand far more than the other?

Watching how a baby uses their hands is one of the quiet ways we get to know them in their first year. One of the things parents ask me about is the moment they notice their baby seems to reach for almost everything with the same hand, and start to wonder whether their little one is simply going to be right or left handed, or whether it is something worth paying a bit more attention to. It is a very fair thing to wonder about, because so much of what we see in these early months is completely typical, and at the same time there are moments when noticing something early can make a real difference.

In the first year, a baby's two hands are very much like new teammates, taking turns, meeting in the middle, and gradually working out how to do the bigger jobs as a pair, well before either one becomes the captain. The captain, the hand we eventually think of as someone being right or left handed, does not usually step forward until much later, often between two to fours years of age. So when one hand is doing most of the reaching and playing well before the first birthday, it is less a sign of your baby's personality showing through, and more a sign that one teammate is carrying most of the game, and that is the part that is worth understanding a little better.

It often helps to know what these early months usually look like. Around three or four months, most babies discover their own hands and begin bringing them together in the middle of their body, clasping them and pulling them up to their mouth to explore. By around six months they are generally reaching with either hand and enjoy passing a toy from one hand to the other across the middle. Both hands getting plenty of practice, taking turns and helping each other along, is exactly what we hope to see, because it is the groundwork for everything from holding a bottle to managing a spoon to doing up a zipper years down the line.

A great deal of the time, a one handed moment is simply a moment. If the hand your baby favours changes from one day to the next or depending on which toy has caught their eye, if the quieter hand still comes in to steady a bowl or hold one end of a toy, and if your baby happily brings both hands together to clap or to reach for their feet, then what you are most likely seeing is just a baby being a baby. A few lopsided moments on their own rarely mean very much, and they are a normal part of all the practising that is going on.

It becomes more worth a conversation when, over a few weeks, you find yourself noticing the same things rather than the occasional one. Some of things you might have been seeing are:

• One hand is consistently favoured before about 6-10 months of age

• The other hand often staying fisted, tucked, or held back — not reaching, not exploring, not really joining in with the other hand. 

• Trouble bringing both hands together at the middle, or passing a toy from hand to hand. One hand might look slower to open, not as efficient at picking up a toy or snack, or when they reach it's not as far as the other hand. 

• A difference you can feel as well as see — one side seeming stiffer, or looser, or simply *less awake* than the other.

If some of this feels familiar, I would encourage you to look into it rather than wait, and I want to be honest that this comes from a place of reassurance rather than worry. A baby's brain in these first couple of years is extraordinarily good at learning, building and reshaping itself at a pace it will never quite match again, which makes this the very best time to help a hand that needs a little coaxing to take its turn. 

There is encouraging research into Baby-CIMT and bimanual therapy, a gentle and playful kind of therapy designed for babies who are showing this sort of early difference in how they use their hands, which found that it helped little ones use their affected hand more than gentle handling alone did. It is the same kind of approach that trusted centres here in Toronto, such as Holland Bloorview, draw on for early hand development. 

Looking into it does not mean a label, and it does not need a doctor's referral to begin. Often it is as simple as a paediatric occupational therapist watching your baby play for a little while and letting you know, in plain language, whether those two hands are working together the way we would hope to see at this age, and what, if anything, might help. [Note: An OT assessment looks at how your baby moves and plays, and it is a helpful first step rather than a replacement for your family doctor/paediatrician, so anything you have noticed is always worth mentioning to them.]

Getting support early, while everything is still forming, gives children the very best chance to build both ability and confidence. If you have been watching one little hand do less and would like to understand more, I would be happy to walk you through it. 

References

Novak, Iona, et al. "Early, Accurate Diagnosis and Early Intervention in Cerebral Palsy: Advances in Diagnosis and Treatment." *JAMA Pediatrics*, vol. 171, no. 9, 2017, pp. 897–907.

Eliasson, Ann-Christin, et al. "The Effectiveness of Baby-CIMT in Infants Younger than 12 Months with Clinical Signs of Unilateral Cerebral Palsy: An Explorative Study with Randomized Design." *Research in Developmental Disabilities*, vol. 72, 2018, pp. 191–201.

Kaya, Eren, et al. “The Effect of the Modified Constraint-Induced Movement Therapy on the Upper Extremity Functions of Obstetric Brachial Plexus Palsy Patients.” Cureus, vol. 14, no. 12, 2022, article e32718, doi:10.7759/cureus.32718.

*Building Skills Together, paediatric occupational therapy on the Danforth, for families across Toronto's east end.*