The system measures the subject’s ability to control the platform’s angle of tilt. The patient’s performance is noted as stability index. The stability index represents the variance of the platform displacement in degrees. A high number is indicative of a lot of motion, which indicates balance problem. The system supplies the data regarding the balance of the tested subject. These data include (1) anteroposterior
(AP) stability index which represents the variance of the foot platform displacement in degrees, from level, for motion in the sagittal plane. (2) Mediolateral (ML) stability index which represents the variance of the foot platform displacement in degrees, from level, for motion in the frontal plane. (3) Overall stability index: represents the variance of the foot platform displacement in degrees, from level, in all motions during the test.