Dorsal Forms in Japanese School Children (Age of 13 and 14 Years) Studied by Moiré Topography

Abstract

The moire topography method is especially popular in spinal deformity diagnosis and estimating the success of surgery. However, this method had not hitherto been applied to healthy subjects.
This report deals with dorsal forms of 71 boys and 59, girls, aged 13 and 14 years, using moire fringe topography. All subjects were diagnosed to be normal at the school scoliosis screening. Classification of moire patterns and photogrammetry, and computerized fringe analysis were made. The results are summerized as follows.
(1) Dorsal moise patterns were classified into 7 types. The patterns without relief at the scapular inferior angle (i, e, fatty backs) are more frequent in girls, and patterns showing the clear relief (i. e. thin backs) more frequent in boys.
(2) The distance between the lumbar concavity and the center of the moire fringes (dorsal convexities) on both sides, and the angle between this line and the dorsal center line represent negative correlation to the number of fringes (depth) between the lumbar concavity and dorsal convexity.
(3) Twenty four boys' and eight girls' dorsal form topographies classified as Type IV, showing thin symmetrical features, were analyzed using the RIFRAN interactive fringe analyzer. Neither bilateral nor sex differences were observed in the two-dimensional course of protuberance line on both sides of the vertebral column. In the protuberance line three-dimensional course (depth), measured from C7 coordinates, no laterality was detected in either sex. However, this depth is deeper in girls than in boys.
(4) No sex difference was observed in measureing a straight line on the vertebral curvature. However, the inflection point is situated at 4cm heigher position in boys than in girls. Depths and curvature radii at thoracal kyphotic point and kyrtorrhachic point show that the former is more emphasized in boys and the latter more emphasized in girls.
(5) Charts representing several kinds of individual doreal form characteristcs are presented.