Abstract
Human body dynamography(HBD) is proposed as a convenient system for analyzing and evaluating human body motions specifically the torque acting at joints of a human body. Torque intensity is visually displayed using a color scale. A kinetic model of the human body, consisting of fifteen rigid cylinders equivalent to the body segments and the equations of motion, is derived to estimate each torque during joint action. A sequence of motions in both the frontal and sagittal planes is simultaneously taken by two video cameras, and the coordinates of individual joints are digitized with a PC. Visualization of torque was tested on the planar motions in a popular physical exercise of a Japanese radio program. Rings centered on individual joints were drawn on a skeletal model, and colored corresponding to the magnitude of torque. Torque was normalized by the cross·section area (Normalization 1) and volume (Normalization 2) of each segment. Additionally, HBD was compared with thermography to evaluate the normalizations.
