More on the gyroscope-like mechanism that helps us keep our balance:

The inner ear functions like a gyroscope. Three orthogonally oriented structures, called the semicircular canals, sense the orientation of the head via movement of fluid within the canals. Nerves connected to these structures send a train of neural signals to the brain, which integrates that information with visual signals and other cues to maintain balance and stabilize vision–for example, to keep our eyes focused on one point as we walk, eliminating the jittery, handheld-camera effect we might otherwise perceive.