An instrumentation system and an improved methodology for the automatic measurement and real-time evaluation of man's postural equilibrium parameters have been developed. The system is based on the principle that the mechanical oscillations of man's physiologic gravicentre†can be translated into electrical signals, which can be recorded and analysed. The apparatus consists of an electronic platform which continuously measures the location of the physiologic gravicentre in a horizontal plane, and a circuit which reduces these measurements to quantitative indices of the postural equilibrium and displays them in numerical form immediately after the test is completed. A utomatic measurements, real-time evaluation of both amplitude and frequency of body oscillations, and operational simplicity are essential features of this instrumentation. The system could be used in various specialized disciplines, such as clinical medicine, otorhinolaryngology, industrial, aerospace and undersea medicine, as well as sports physiologic research.