Moving toes
Why we are unable to move our toes independently as we do our fingers?
S. SHANMUGANANDAM
Chennai
Fingers and toes are morphologically different. The function
of an animal is different from human, as human
assumes an erect posture. Animals run with four legs, in a
coordinated way. But a human, even if he assumes four leg
posture cannot run, as he does with two legs.
Animals drink water by ending its neck into the surface, and to make it easy when the forelimbs bend to lower the head, the hind limbs extend or rise to make it easier. This is called Tonic Assymatric reflex, by neck contraction. This phenomenon may be seen in a newborn.
The new born cannot extend the hand, i.e. it cannot open the fingers by itself, voluntarily. The movement of thumb is across the palm, till the myelination process becomes complete.
As the child learns to stand, the morphology changes entirely. Hence the movements are organised according to the need of the human requirements. Moreover, once the organisation of the movement is postulated by the brain according to the evolutionary changes or functional changes, the muscles get reorganised to the need.
For example, the different planes of origin of the muscles in the forearm and leg control the movement of the hand and toes. The area of their origin and insertion decides the need of movement and nature of movement. For example, there are two groups of muscles in the forearm, attaching itself to the different portion of finger bones at different sites to perform finer movement, as we play a guitar or veena.
Such finer and planned insertion is not available in the toes. Hence individual movement cannot be performed as in fingers. The need is designed, and organised by the nature itself. At the same time, if one wants to train the toes for individual movement as we see in persons who train their toes to write, brush, paint etc., when they lose their hands, the morphology is altered and brain movements are reorgansied.
This is called neuroplasticity, wherein the brain get adjusted or altered to the training program. This aspect is well taken up scientifically, wherein we neurologists train the brain to activate the paralyzed limbs in the event of paralysis. It is possible now.
Dr. V. NAGARAJAN
Professor Emeritus in Neuro Sciences
Tamil Nadu Dr MGR Medical University
Madurai, Tamil Nadu
Printer friendly
page
Send this article to Friends by
E-Mail
Sci Tech
