How does a cat manage to fall on its feet?

Although cats are excellent climbers they do occasionally fall, and when this happens a special 'righting reflex' goes into instant operation.

Without this a cat could easily break its back. As it starts to fall, with its body upside-down, an automatic twisting reaction begins at the head end of the body. The head rotates first, until it is upright, then the front legs are brought up close to the face, ready to protect it from impact. (A blow to a cat's chin from underneath can be particularly serious.) Next, the upper part of the spine is twisted, bringing the front half of the body round in line with the head.

Finally, the hind legs are bent up, so that all four limbs are now ready for touchdown and, as this happens, the cat twists the rear half of its body round to catch up with the front. Finally, as it is about to make contact, it stretches all four legs out towards the ground and arches its back, as a way of reducing the force of the impact. While this body-twisting is taking place, the stiffened tail is rotating like a propeller, acting as a counterbalancing device. All this occurs in a fraction of a second and it requires slow-motion film to analyse these rapid stages of the righting response.