BIODYNAMIC MODELING AND RESPONSES OF HUMAN UPPER-BODY AT SEATED POSTURE SUBJECTED TO EXTERNAL STIMULATING FORCES IN BOTH HORIZONTAL AND VERTICAL DIRECTIONS

In this paper, a biodynamic modeling of the human upper-body at the seated posture subjected to external stimulating forces in both the horizontal and vertical directions is developed. Based on d'Alembert's principle, the non-linear biodynamic equation of the modeling, which has the characteristic of two dimensions and one degree of freedom, is obtained. Furthermore, the responses of frequency and amplitude of the non-linear biodynamic equation is investigated by employing the KB method in the non-linear theory. The responses of realistic human parameters and the external stimulating forces on the modeling are simulated by MATLAB. The results show that the modeling presents the rich non-linear characteristic. It is given and discussed for the parameter identification and stable area of keeping the upper-body stabilization at the seated posture. The paper can be used to explain and estimate the mechanism of maintenance of stable trunk posture due to the mechanical shocks transmitted through the vehicle seat.

3-D BIODYNAMIC CONSTRAINT CONDITIONS WITH THREE SEGMENTS AND TWO ARTICULATING JOINTS ON THE HUMAN KNEE

In the paper, the 3-D biodynamic constraint conditions with three-segments (femur-patella-tibia) and two articulating joints (patellofemoral joint and tibiaofemoral joint) on the human knee are established. These constraint conditions of motion accommodate two situations: a two-point and a single-point contact on the patellofemoral joint and tibiaofemoral joint. On the other word, the present constraint modeling includes both rolling and sliding motions between the patella-femoral joint and tibia-femoral joint. This study can be explored a realistically 3-D biodynamic modeling of the human knee joint or human lower extremity.