This surprising discovery about shaking babies will save lives
Babies are at far greater risk of brain damage than previously thought.
Even activities that seem innocent, like a run in a jogging stroller, can inflict abusive head trauma. And head injuries often go entirely undetected, so parents unwittingly repeat the same harmful behaviors.
These conclusions, which come from a new study I co-authored, must be used to better educate new parents and inform manufacturers as they design car seats, safety helmets, and the like.
Abusive head trauma, or AHT, is typically referred to as “shaken baby syndrome” — the consequence of awful, deliberate abuse. Every year, an estimated 1,300 infants suffer this brain trauma. Roughly one in four tragically dies. Of those who survive, about 80 percent develop lifelong disabilities.
Of course, the overwhelming majority of parents would never intentionally harm their children. But it’s possible to inflict AHT without even knowing it.
There are several reasons why this unsettling truth is just now coming to light. It’s difficult to diagnose AHT. Some cases result in noticeable injuries, including bone fractures. But others result in far milder symptoms. Many victims of AHT show no signs of trauma.
Plus, studying the biomechanics of AHT — what occurs inside a child’s skull when his or her head moves back and forth rapidly — presents its own challenges. There’s no ethical way to observe or replicate such injuries in a scientific setting.
Thankfully, there’s another way to study the problem. My colleagues and I used computer models to simulate the biomechanics of AHT. Specifically, we looked at how the cerebrospinal fluid cushions the brain when a child is shaken repeatedly.
What our models revealed is startling. Even at the lowest frequency we studied — two shakes per second — a single shake is dangerous. After that initial shake, the cerebrospinal fluid stops cushioning the brain altogether, causing the child’s brain to collide with the skull wall.
In other words, it doesn’t take a violent act of frustration to damage a baby’s brain. Something as ordinary as playfully tossing a child in the air or jogging with a baby could inflict head trauma.
Our conclusions suggest several strategies for preventing head trauma in young children. The first is simple — parents must avoid any activity that shakes their infant’s head even once, however harmless it might seem.
Designers should rely on biomechanical models when designing items like car seats, strollers, and other products. In 2018, U.S. emergency rooms treated children under five for 59,000 injuries related to nursery products. Strollers were involved in 8,200 of those injuries. Across all of these incidents, the child’s head was the most commonly injured part of the body.
Better-constructed products based on the latest biomechanics research could go a long way toward reducing head injuries in children.
At the very least, researchers should use biomechanical simulations to evaluate the safety of existing baby products. Newer products are not necessarily safer than older ones. In February, biomechanics researchers found that World War I-era combat helmets provided better protection from certain kinds of explosions than current military helmets.
The latest biomechanics research reveals that babies are more vulnerable to head trauma than previously thought. It’s time to minimize this trauma — or eliminate it — by using these findings to educate new parents and design safer baby products.
Milan Toma, Ph.D., is an assistant professor in the Department of Mechanical Engineering at New York Institute of Technology College of Engineering and Computing Sciences.