Researchers have identified a highly flexible region in cats' spines that allows them to rotate their bodies sequentially while falling, ensuring they land on their feet. Experiments on cat spines and high-speed videos of falling cats support the tuck-and-turn model over other theories. The findings suggest cats may prefer twisting in one direction due to anatomical asymmetries.
Cats' ability to right themselves during falls has puzzled scientists for over a century, with three primary theories explaining the phenomenon. The propeller tail idea posits that swinging the tail causes the body to rotate oppositely, but Greg Gbur at the University of North Carolina at Charlotte notes, “The tail seems to be the least important, because if it doesn’t have a tail it can still turn over.” The bend-and-twist model involves bending the body into a right angle and rotating the front and back halves in opposite directions. Alternatively, the tuck-and-turn approach has the cat extending its rear legs while contracting the front ones, twisting the front first, then swapping to adjust the rear.
Yasuo Higurashi at Yamaguchi University in Japan and his team tested these ideas through two experiments. They examined the spines of five deceased cats, finding that the thoracic spine—mid-back region—had a range of motion three times greater than the lumbar spine in the lower back. “We compared the flexibility of the thoracic spine and lumbar spine in cats, and we found that the thoracic spine is very flexible,” Higurashi said.
In a second experiment, high-speed video captured two adult cats dropped from 1 meter, showing they completed front rotations tens of milliseconds before the rear. This supports the tuck-and-turn model. Gbur, author of Falling Felines and Fundamental Physics, commented, “My general impression has been that the bend-and-twist is the most important, but this paper actually makes me reassess a bit and give a little bit more credence to the tuck-and-turn.” He added that the models are not mutually exclusive, as “nature tends to look for the most effective method, which may not be simple.”
An intriguing observation was that both cats rotated to the right—one consistently, the other in six of eight trials. Gbur noted anecdotal evidence from his videos suggesting a directional preference, possibly due to asymmetries in internal organs.
The research appears in The Anatomical Record (DOI: 10.1002/ar.70165).
