Patent ID: 7361150

Claim:
A method for evaluating the balance forces of a skeleton within a subject's body, comprising: a) arranging the subject between an X-ray source and a target plate in a reproducible position using a stabilizing support for stabilizing the subject; b) producing a radiographic image of the skeleton, the skeleton having segments articulated to one another, taken in a plane generally perpendicular to rotation axes of the articulations of the skeleton, c) simultaneously determining a position of an overall axis of gravity of the subject's body on the radiographic image, d) selecting the skeleton segments articulated to one another on the radiographic image, identifying positions of the segments and those of the articulations, and assigning a weight of the subject's body segment corresponding to each skeleton segment, e) identifying directions and selecting anchoring points on the radiographic image of main tensor muscles balancing the subject's skeleton including a spinal erector muscle and a muscle extending from a dorsal vertebra D 12 to the lumber vertebra L 3 , and f) determining an intensity of a restoring force exerted by the main tensor muscles by calculation based upon the identified directions and anchoring points of the main tensor muscles, wherein the restoring force compensates for a rotational moment of the force of gravity applied to each skeleton segment about a lower articulation of said skeleton segment, wherein the subject is placed in a stable balance position, successive positions of the overall axis of gravity for a few seconds are stored with a frequency of several acquisitions per second, wherein the stored positions comprise an elliptical cloud of positions, and wherein a dispersion ellipse which envelopes said cloud of positions is determined, and wherein radiographic images corresponding to an overall axis of gravity whose position lies in the dispersion ellipse are selected.