Image is from the Journal of Medical Genetics

Have you ever wondered how our hand develops? How it is able to do so many things?  

Development of the hand

Our hands actually start out as little blobs that develop little bone like cartilage structures that later form our fingers. At birth we have 19 bones in total in each hand with fingers, and no wrist bones. Initially these bones have spaces between them and as we grow and develop our hands more, these spaces decrease.

As a newborn, the grasp reflex is so strong that it keeps the hand in a fist when asleep. When babies are awake, the baby might bat hands in the air and even use rotation movements while looking at something. This is the foundation for the development of eye-hand coordination. At this stage the baby often brings their hands together in the middle of their bodies which helps the baby to develop awareness that there are two sides to the body. This awareness later develops into ‘bilateral integration’ which allows someone to use both sides of the body at the same time.

Around 3-4 months the baby starts to push on his/her hands to lift the head and upper trunk during tummy time. This helps to strengthen the shoulders and hands, and helps with the process of opening the hand, forming arches and integrating the grasp reflex.

Reciprocal crawling further strengthens these muscles and has many benefits including cognitive benefits. By 5 months, the baby is so motivated to interact with the environment that s/he voluntarily opens and closes his/her hand to hold objects, although can be uncoordinated when releasing objects.

With practice and by manipulating different objects, different grasps and pinches develop which makes manipulating objects easier. The more the hands manipulate a variety of objects, the more sensory input they receive and the more refined these grasps and pinches become.

Finally, we have hands that can open and close buttons during dressing, control cutlery during mealtimes, open lunchboxes and other packages, and even write letters, numbers, words, sentences and even complex stories.

The development of the hand is fascinating and there is so much more to learn.

Feel free to reach out for any help with hand function for you or your little one with one of our Occupational Therapists here at Hanrahan Health.  Contact us via our website, or via email at admin@hanrahanhealth.com.au. 

References:

Visser, M., Nel, M., Vries, J.D., Klopper, E., Olën, K., & Coller, J.M. (2014). In-hand manipulation of children aged four and five-years-old: translation, rotation and shift movements, in Bloemfontein. South African Journal of Occupational Therapy, 44, 22-28. https://www.semanticscholar.org/paper/In-hand-manipulation-of-children-aged-four-and-and-Visser-Nel/6beadff01ca41f88eee9e11111e6ca533ca7ddc6