The underlying principle for all balance testing is to measure the functional ability of a subject to integrate different aspects of sensory inputs into a unitary balance command during stance, especially when this ability is challenged. To judge whether the stance is normal or not, SwayStar™ provides reference data of normal subjects, over the age range 6-82 years.

Standing tasks are the easiest to perform but can be challenged by modifying the efficacy of visual (eyes closed) and proprioceptive (foam support surface) feedback. There are four two-legged and three one-legged stance pre-defined protocols available in SwayStar™. These comprise the stance part of the standard "balance deficit screening" sequence. Test duration is 20 secs or until the subject losses balance.