I work with a small group of professionals from different disciplines, but all of us focusing on child development in the department of Developmental Paediatrics and Child Neurology at MOSC Medical College, Kolencherry.
This blog has been infrequently visited with updates as I felt hesitant to write more than what I regularly write on: waymarksonajourney.blogpot.com
But a colleague, Ms Shalini Shaji suggested that I revive this blog as it can be a good dialogue starter with parents on important issues on child development. Shalini has offered to co-ordinate and feed me with questions which parents ask and be in touch with parents and professionals to continue this communication process.
Let me respond to a question that Ms Shalini Shaji sent me yesterday, which she heard from a parent:
My child is three and half years old. Sometimes he uses his left hand to take something or when he gives a high five. I am not really sure if he is right handed or left handed. How can I confirm that? Is it alright for him to use either hands?
I was prompted to go back to my archives of photographs and came across this ballon play during a children's party.
In the second photo the child in the yellow shirt touches the balloon with the left hand and in the third picture he plays with the balloon with the left hand. He to me appeared to be between three and five years of age.
We come across about ten percent of adults to be left handers. Usually there would be other members as well as in the family with a preference for using the left hand. But most adults having been forced to use the right hand even though they were natural left handers from their childhood, would end up using the right hand for eating, writing etc, but would prefer to use the left hand for other activities. I know of a child at ten years using his the left hand to bowl a cricket ball although uses the right hand to eat and write.
When we come to study this in children there are three questions that surface in my mind.
1. Is she or he a natural left hander at 3-5 years!
This can be found out by finding out if there are other members in the family who are more comfortable with the left hand. Examine the thumbs and the great toes of a child and see if there is a difference between the right and left side. Whichever thumb or great toe is marginally bigger side, it is likely to be the dominant hand or leg.
One can measure the muscle girth at the calf muscle level and upper arm level at a fixed point in both sides and observe if there is a difference in the bulk of the muscle on one side. The muscle bulk might be larger by at least half a centimetre on the side which is a child's natural dominant hand or leg.
Another information that would be of value is to know from parents as to which hand the child used regularly for play activities. Usually by 2 to 3 years a child prefers to use one hand as the leading hand to do many activities such a bouncing a ball, holding a racket or for drawing or reaching out to say bi!
Many parents would insist on a child using the right hand for eating and writing. The history of parents or teachers forcing a child to change from the left to right hand ought to be enquired into. About fifty percent of natural left handers would have changed into using the right hand under such circumstances. This can be proved by making a child do activities with both hands and looking for original handedness based on the dexterity with which a child performs with the hands.
2. What is acquired left handedness!
A child might have been born with a difficulty on the right side or weakness of the right hand, in which case from early childhood such as from six months onwards, when a child normally reaches out to receive objects in the hand, would use the left hand. He or she may under use the right hand. In fact the the right hand might appear to be clumsy functionally.
When a child under two years prefers to use the left hand most of the time, it is contrary to the natural pattern in childhood. Till three years or so most children use both hands equally. The cerebral dominance which gets established by two to three years determine as to which hand would evolve to be the dominant hand.
All children till two to three years would be bimanual; majority of children are natural right handers; only less than ten percent of children would be natural left handers; a child who is a natural left hander if made to return to use the right hand, the child would show indications of his preference for the left hand for activities which require strength or dexterity.
All children who because of weakness on the right side, resorting to use the left hand can come across some challenges.
3. What are those challenges!
When a child who was originally wired to be a right hander when using the left hand because of some weakness in the right side might still have the left cerebral hemisphere as the dominant hemisphere. It is the dominant hemisphere the language centres are located in majority of the situations. When owning to a difficulty in the left hemisphere the right hand of the child is waker, he or she would prefer to use the left hand.
In such a situation it is likely that the left hemisphere might still be the language centre. If the left hemisphere suffered an insult the neuro-plasticity might repair the left hemisphere and still retain the left hemisphere as the language centre. But if the insult to the left hemisphere occurred before a baby is born or at birth or in the first year of life, it is likely that the brain might naturally shift the dominance of hand or speech or both to the right hemisphere. These are questions which can be answered by careful clinical examination, developmental appraisal and brain imaging studies.
So there are two scenarios: there are natural right handers, who form the majority. There are natural left handers which is a small group. A natural right hander would shift to left and when there is an insult to the left hemisphere.
The second scenario is : A natural left hander might have the left hemisphere as the dominant hemisphere, as against the norm of the opposite hemisphere being the dominant hemisphere locating the centres of handedness and speech. A natural left hander might have the right hemisphere as the dominant hemisphere in which case if an injury were to occur to the right hemisphere, it is likely that he might start using the right hand, in which case the left hemisphere takes over some functions of the right hemisphere.
Let me conclude.
The right handedness associated with left cerebral hemisphere dominance is likely to be more definitive. Where as in natural left handers, one is not sure whether the corresponding hemisphere is dominant or the opposite is.
How are we to respond to handedness!
I am inclined suggest that the child should choose his or her handedness. If the child has a weakness of one side of the body, then take an opinion from doctors, speech therapist, occupational therapist and teacher to decide which way to proceed.
Al children are proficient in using both hands for play activities till about 2 years and the shift to use one hand in preference to the other hand would happen between two and three years. It is for parents to keep watching how the handedness evolves in children.
There are ways to strengthen either of the hands or legs if weakness is the reason for the child to avoid using one side. This support ought to be offered as early possible, as limited use or non use of one side would lead to wasting of muscle, which a is a big disadvantage and difficult to overcome once it has occurred.
I have come across some instances when children fumble in language development when they were forced to use the right hand, although they wee natural left handers. This is unfortunate.
Let me request parents to overcome the cultural inhibitions associated with the use of left hand and save children from having to struggle to use the non-dominant hand.
Let me suggest that readers can use e-mail to respond to or raise more questions or for clarifications by posting them on: childdevelopment@moscorg.com
M.C.Mathew (text and photo)
No comments:
Post a Comment