The Mystery Behind Why Babies Kick in the Womb, Explained


| LAST UPDATE 12/31/2022

By Daria Appleby
Why Babies Kick Inside Womb
ULISES RUIZ/AFP via Getty Images

This one is for all those moms out there who have felt their little one kick before entering the world. For centuries, there has been a mystery surrounding why fetuses begin to kick when they're still inside the amniotic sac. The movement can start as early as 16 weeks when the nervous system has just started to develop. Now, published studies have revealed the reasons behind this inevitable mystery.

Long-wanted answers have been provided by a peer-reviewed study in the journal, Proceedings of the National Academy of Sciences. They have touched upon the fact that unborn babies roll around inside a mother's womb. While these movements have been forever dubbed as random acts of a baby's growth, there is a deeper meaning behind the flutters. That being said, scientists from the University of Tokyo have discovered that early child development is dependent on "working out in the utero," primarily focusing on hand-eye coordination. Lead study author, Hoshinori Kanazawa, said, "We were surprised that during spontaneous movement, infants' movements 'wandered' and they pursued various sensorimotor interactions... We named this phenomenon "sensorimotor wandering."

Why Babies Kick Womb
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After conducting and investigating further, according to the Journal of the Royal Society Interface, "the average in utero kick can carry a force of more than 10 pounds." Nevertheless, a new case study has revealed that the whole point surrounding fetal movement is to help them develop in the long run. After birth, babies naturally and gradually discover how to move their bodies around. This includes hand and leg movement, grabbing things, turning their heads, and eventually, crawling and walking. It turns out the neurological activity that took place inside the womb serves the purpose of preparing them for their movement in the outside world. After being confined to a placenta sack for nine months, some movement has to take place before birth. The scientists used motion capture technology to record the joint movement of 12 newborns. They found "that patterns of muscle interaction developed based on the babies' random exploratory behavior and later helped them to perform sequential movements," says the New York Post. Where previous research focused on movements in the joints, this latest study focused on muscle activity and sensory input throughout the whole body. Repeated sensory interactions help unborn babies remember these movements after birth and growth.

Researchers have reported how a better understanding of how our sensorimotor system develops can contribute to findings referring to the origins of human movement. What's vital to take away from the study is how spontaneous neuronal activity varies, enhancing discoveries of how a baby's body, as well as the brain, develops in the womb.

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