Why Do Cats Usually Land on Their Feet?
Physics, Physique and Reflexes
We all know that when cats fall, but not feet-first, they still land on their feet almost every time. Most of us just assume that's the end of it. The fact is they often suffer horrific injuries.
But first, a few words about how they manage to land on their feet. Cats have an exceptional sense of balance, which is why they can walk so easily on a narrow ledge. They also lack a collar bone, and their spine is extremely flexible.
Those skeletal advantages give cats freer movement of their front legs, and the ability to bend and rotate their bodies. When they do fall they can right themselves in less than a second, a reflex developed usually by the time they're seven weeks old.
Although this righting reflex gives them the ability to somewhat cushion a hard landing from dangerous heights, it doesn't necessarily protect them from injury. And veterinarians are seeing more and more cats with injuries incurred in long falls.
They call it high-rise syndrome, and it's more common now for several reasons. More and more, people are keeping their cats indoors. Cats love to sit in the windowsill, but if the screens aren't secure they can fall out.
The proliferation of apartment buildings, condo complexes, and loft units has created much more housing above the second floor, and much of today's new construction features balconies, decks and porches.
The most severe injuries generally occur in falls from two to seven floors. That's because of the laws of physics, which I couldn't grasp in high school. I can't grasp them now, either.
I do know this, though. A falling cat is not a textbook example of aerodynamic perfection. Its loose skin, haircoat, and tail create considerable drag.
A blackboard diagram would show an arrow pointing downward representing gravity. This force causes the cat to fall at a rate of speed determined by its body weight. Another arrow pointing upward would represent the force of the air against which it is falling. That would be the drag, created by the righting reflex.
The cat's rate of descent accelerates between the second and seventh story. Once it has fallen about seven stories it achieves terminal velocity. That's when the force of air against its outstretched body equals the force of the gravity that's pulling it earthward.
Although the cat may fall several more stories, it isn't traveling any faster than it was when its fall reached the equivalent of seven stories. The cat relaxes because it has lost the sensation of falling.
With its joints loose and its legs flexed instead of extended, the impact of hitting the ground is more evenly distributed throughout its body. The cat is more likely to survive a fall of greater than seven stories because it had time to reach terminal velocity.
But the injuries cats sustain can be terrible, and even fatal. Skeletal injuries include broken facial bones, jaws, teeth, ribs, legs, and spine. The lungs, liver, diaphragm, and other organs within the abdominal cavity can be damaged, as well. While they may survive the fall, their injuries may be so severe that euthanasia is the only option.
As reported on webmd.com, veterinarians at the ASPCA’s Bergh Memorial Animal Hospital see approximately three to five cases a week during the warmer months. There is some encouraging news, though. There is a 90-percent survival rate for cats that are high-rise syndrome victims if they receive immediate and proper medical attention.
As is so often the case, prevention is the key. Make sure screens are secure and that cats can't get onto the railings of decks, balconies and porches. It’s also a good idea to plant soft shrubs beneath windows and decks, a few feet from the foundation; just in case.
© 2012 Bob Bamberg