Scientists have finally figured out why cats land on their feet when they fall

The ability of cats to almost always land on their feet has long attracted the attention of scientists. This phenomenon was first studied in detail back in the 19th century, yet new research shows that the mechanisms behind this trick have still not been fully revealed. Japanese scientists have found that the varying flexibility of different sections of the cat's spine plays an important role. The study was published in the journal The Anatomical Record (AR).

The mystery of the "falling cat" has been known in science for over a hundred years. In 1894, French physiologist Étienne-Jules Marey was the first to capture on a high-speed camera how a cat flips in midair. In the photographs, the animal begins its fall without rotation but manages to turn and land on its feet, which for a long time seemed to contradict the law of conservation of angular momentum.

Later, physicists demonstrated that a cat can change its orientation in the air by rotating different parts of its body relative to each other. However, the anatomical features that enable it to do this remained far less studied.

A team of researchers led by physiologist Yasuo Higurashi from Yamaguchi University set out to study specifically the structure of cats' spines. To this end, the scientists examined the spines of five animals, preserving the intervertebral discs and ligaments.

The spine was divided into two regions — thoracic and lumbar — and their capacity for twisting, stiffness, and range of motion were measured. It turned out that the thoracic section is significantly more flexible: its rotational range is approximately three times greater, and its stiffness is noticeably lower than that of the lumbar section.

In addition, the thoracic section of the spine has a so-called "neutral zone" — a range of motion where the spine can rotate with almost no effort. The lumbar section has virtually no such zone.

To test how this affects falling, the researchers used a high-speed camera to film the falls of two live cats. The animals were carefully dropped eight times from a height of approximately one meter onto a soft surface.

The analysis showed that the cat does not flip in a single movement. First, the front part of the body rotates, and then, with a slight delay, the rear part follows. The time difference was approximately 70–90 milliseconds.

According to the scientists, this occurs because the front part of the body is lighter and connected to the more flexible thoracic section of the spine. The rear part, which is heavier and stiffer, follows after it.

The researchers believe that this spinal feature helps cats not only flip in midair but also perform other complex movements — for example, sharply changing direction while running or jumping.

The authors of the study note that additional research is needed to draw definitive conclusions. Nevertheless, the results obtained help to better understand how spinal anatomy affects the agility and movements of mammals.