Vector Statokinesigram —A New Method of Analysis of Human Body Sway—

Abstract

The vector statokinesigram (abbr. V-Skg.) is a graphic record of the magnitude and direction of the electronic voltage of body sway converted through an A/D converter, which is computed by means of a microcomputer consisting of a specially designed program. This program displays on a CRT 72 radial lines arranged 5 degrees apart. The magnitude of each radial line is then displayed and printed. The computed pattern of V-Skg. reveals favourably the changes and differences in the magnitude and direction of body sway. This new method was used to study the body sway of healthy young adults, healthy elderly subjects and patients with dysequilibrium. 1) Twenty-nine healthy adults, average age 25.8 years (range 19 to 32) were examined by Skg. and analysed by means of the computer-technique for “V-Skg.”. According to the patterns of Skg. and V-Skg., they were classified into six groups; centripetal type, diffuse type, antero-posterior type, multicentric type, lateral-swaying type and “more stable-with eyes closed ” type. The total length of the sway path and vector analyses of 18 directions (20 degrees apart) were summed up to calculate the normal range (mean value with standard deviation), and the occurrence rates of all cases in each group were listed. 2) Sixty-five healthy aged persons, average age 72.6 years (range 62 to 84) were examined and analysed in the same way. There were several differences in total length of sway path and of parameter in V-Skg. between the young adults and aged persons. 3) Eight patients with dysequilibrium (of peripheral and of central origin) were examined and compared to the normal groups of each type. There were significant increases in body sway compared to lateral-swaying in V-Skg. of the peripheral origin. There were also marked increases in body sway to antero-posterior in V-Skg. of the central origin. 4) The clinical data, and results of Skg. and V-Skg. of two representative cases are described in more detail. V-Skg. showed significantly even small changes in directional predominance in body sway on a corresponding radial direction and magnitude, which could not be demonstrated on an ordinary Skg.,. © 1983, The Society of Practical Otolaryngology. All rights reserved.