Balance is defined as our ability to control our body's center of mass so that we can remain upright, even when we encounter a disturbance, such as a bump from another individual or when we trip over a crack in the sidewalk. Multiple systems contribute to our ability to balance in standing and moving environments. The sensory systems (vision, somatosensory, and vestibular) provide us with information about the surrounding environment and the motor system uses the information from the sensory systems to produce coordinated postural muscle activity to help us keep our balance.