“…The human model was assumed to have 15 rigid segments: 1) head/trunk including head, neck, thorax and abdomen, 2) pelvis, 3) right and 4) left upper arms, 5) right and 6) left forearms, 7) right and 8) left hands, 9) right and 10) left thighs, 11) right and 12) left shanks, 13) right and 14) left feet and 15) luggage. Thus, it had 14 joints whose centers were estimated from marker positions 2,[6][7][8] A global reference system, X, Y, and Z, and a local reference systems, x, y, and z, for each segment were employed by a Cartesian coordinate system. The positive directions of the X, Y, and Z axes were anterior, cranial and right lateral, respectively.…”