GEEMETRICAL AND INERTIAL QUANTITIES OF THE TRUNK AND ITS TISSUES AND THEIR APPLICATIONS

  • W.S. Erdmann

Abstract

The movement of a man depends on his morphological data. Geometrical and inertial data are the most important. In these investigations they were obtained for 15 male patients 20..40 years old with the help of computerised tomography. The trunk was divided onto three portions. Only one portion of a trunk was scanned for each group of five patients. The trunk was also divided onto five parts: A. .Real trunk i.e. 1) thorax, 2) abdomen, 3) pelvis, and B. Shoulder girdle, i.e. 4) right shoulder, and 5) left shoulder. Every part was then divided onto proximal and distal segments. The picture of every layer (8 mm of height) was divided onto finite number of elements (columns and rows). Each element of known volume (0.1 cm3) which belonged to the particular tissue was given its density value. The density was obtained during2separate investigations, where 50 trunk tissues taken from fresh cadavers were analysed. . The layer included two groups of tissues: A. Unchangeable - bone as support tissue, tissues of feeding system (digestion, breathing, vessel), nervous tissues, and others, and B. Changeable - muscle tissue, fat tissue, and skin. From the analysed trunks following geometrical and inertial quantities were obtained: 1) Linear - straight- and curve-linear, 2) Plane - area of surface of the whole layer and its main tissues, area of surface of trunk's portions projection on the sagittal and frontal planes and radius of center of surface's area, area of surface of skin. 3) Volume and mass of trunk's segments and their main tissues - basic, lung, digestion. muscle, fat, and skin, and also centers of volume and centers of mass. By dividing portions onto subportions there was the possibility of presenting them for new investigated subjects as geometrical figures (a set of frustums), so the calculation of their geometrical data was possible. The same was achieved for unchangeable tissues. For calculation of fat tissue regression equations were given based on skinfolds' measurements. Volume of muscle tissue for an investigated subject can be calculated by subtracting volume of unchangeable tissues, fat tissues and skin from the whole volume of the portion. Applications: 1) Anthropology. 2) Biomechanics, 3) Hygiene of nourishment. 4) Aeronautics and space, 5) Pathology, 6) Theory of training. 7) Safety of transportation, 8) Bioenergetics.