A study finds that there is a safer way to dip in the pool

It depends on form and technique, but a dip in a pool can become a stylish gesture or the aquatic equivalent of a car crash: Scientists at Cornell University in the US used biomechanics to create a safe diving formula. , in an article. Published in the scientific journal “Science Advances” – After measuring the effect of diving with the head, hands and feet, the study authors developed a model to measure the effect of different approaches when the body is submerged in water.

For a novice, untrained diver, the researchers note that spinal cord and neck injuries are more likely to occur during head diving to about 8 metres. At the same time, collarbone injuries are more likely during a manual dive to approximately 12 meters, and knee injuries are more likely during a 15-meter dive.

“Water is a thousand times denser than air, so we’re going from a very dilute medium to a very dense medium. It’s going to see a huge impact,” the study’s senior author, Sunghwan Jung, professor of biological and environmental engineering at the university, explained in a statement.

“Humans can choose how to dive, so we wanted to look at the effect of diving posture. We also wanted to come up with a more comprehensive or general theory about how different shapes dive in water, so we looked at dive fronts in different situations and animals and measured the impact forces of different shapes.”

The study authors used a series of 3D-printed models to analyze the effect of curved, pointed and flat shapes, respectively, on the surface of a water body – by dropping each model into the water, the scientists measured the forces acting on it. and how they spread, an approach that facilitated the development of a theoretical model capable of describing the increase in force in the various forms, and how these forces increased with the rise of the decline.

Next, the researchers plotted the maximum height and impact force that human muscles, ligaments and bones could withstand while diving – and calculated the probability of different injuries (collarbone, spine, knee) at different heights and in different diving positions. “In human biomechanics, there is a lot of literature on fall injuries, especially in the elderly, and sports injuries such as concussions, but I don’t know of any work on diving injuries,” Young said.

Divers often enter the water with their arms extended above their heads, palms together: diving in this direction first enters the water easily and avoids direct impact on the head. Head diving, where the skull hits the water, occurs mainly during an accidental fall and can lead to fatal brain injury. The induced force reaches its peak immediately upon impact. Finally, the entrance to the foot: the peak force is instantaneous and increases with the speed of the impact.

A rapid increase in the magnitude of the force on the impact can be fatal to the human body, as the muscles and soft tissues are unable to absorb short-term impulsive forces. The time development and magnitude of these impact forces depend on the shape and size of the body affected in the water. Thus, according to the study, snorkeling with hands is always the best option, for any occasion.

The study authors hope their work will help people make safer diving choices. For example, diving with feet first is safer than landing high.