Research overview: biomechanics of the cat's mid-air righting maneuver

The physics of how a falling cat rights itself without any initial rotation has fascinated scientists for over a century. This overview surveys the biomechanics of the maneuver, in which the cat bends at the waist and rotates the front and back halves of its body in sequence, tucking and extending the legs to change the rotational inertia of each half. By doing so, the cat can reorient while conserving zero net angular momentum, a clever exploitation of mechanics. The survey relates this analysis to early studies that used photography to capture the falling sequence and to the role of vestibular sensing in initiating the turn. It discusses how the flexible spine makes the two-part twist possible. Understanding the biomechanics shows the righting maneuver is a precise mechanical solution, not magic. It connects the sensory trigger for righting to the elegant body movements that let cats reorient in free fall.