Development and evaluation of an accelerometry system based on inverted pendulum to measure and analyze human balance

An accelerometry system was developed based on the inverted pendulum model and its effectiveness to measure the body's sway path and sway angle was verified in healthy adult volunteers. Sway path represents the body’s movement from its center of mass position projected to the ground surface while sway angle represents the body's orientation from the vertical. Mathematical models were developed to determine the sway displacement and sway angle from the accelerometry system. The resulting values were compared with the manual measurements obtained from a plumb bob based setup and found to correlate closely. Using the developed system, measures that analyzed the contribution of the visual, somatosensory and vestibular systems to balance were obtained. It was found that the accelerometry system followed the principle of motion of an inverted pendulum and provided information that can assist in better understanding of balance and thus it may assist clinicians in diagnosing balance dysfunctions.