Cats have an exceptional sense of balnce--they saunter along high fences only an inch wide,seemingly without fear,walk along rooftops and perch on fence posts to survey the lay of the land. Their ability to perform the equivalent of yoga on a tightrope is the result of fine-tuned coordination of physical and nervous systems. THe cat's supple bodty allows it to move smoothly and it's adapted shoulder blades and collarbones mean that it places it's feet directly in front of each other as it walks--thus walking along narrow ledges requires no special movement. Its tail can be used as a tightrope walked would use a pole, to balance and counterbalance as necessary.
However, it is the feline organ of balance,called the Vestibular apparatus, that gives it its excellent balancing skills. THe vestibular apparatus is part of the inner ear and consists of three fluid-filled semicircular canals lined with millions of tiny hairs. Movements of the cat's head cause the fluid to move around in these canals,moving the hairs and sending signals to the brain telling the cat about direction and speed of any movement.The organ also gives the cat information about it's up/down orientation.
Although the system is present in most mammals,the cat has refined it to allow very accurate control of it's head position. The information that is generated in the vestibular system is combined with that coming from the eyes and muscles to control the whole body,allowing it to maintain a fluidity of balance seemingly without effort. However, like the graceful swimming of a swan, all the action goes on unseen to produce a seamless performance.
One of the cat's unique characteristics is it's ability to land on it's feet after a fall. While it is not ture that the cat lands safely on every fall and from any height, it does have a remarkable ability to save itself by turning around in midair and landing safely on all fours,providing that the fall is not too great.
As a cat falls, it enters into an automatic sequence of events that allow it to flip over--in less than a tenth of a second information from it's eyes and vestibular system set into sequence automatic movements that first turn the cat so that its head is horizontal and upright, then bring its body around. Nerves in the spine cause the back end of the body to turn around,too. The tail acts as a counterbalance to prevent overrotation and,by arching it's back to absorb some of the shock of hitting the ground, the cat usually lands successfully and without injury.