The effects of body segment parameter estimation on the experimental simulation of complex airborne movement

The purposes of this study were to investigate the effects of body segment parameter (BSP) estimation on the experimental simulation of a complex human airborne movement and to assess the applicability of the estimation methods in simulation. A simulation model was developed based on a 15-segment body model with 38 degrees of freedom. The equations of simulation were derived from the principle of angular momentum conservation and the equation of projectile motion.;Three collegiate male gymnasts were involved in the experiments and each performed three trials of double-salto-with-full-twist horizontal-bar dismount. Four Super-VHS camcorders (60 Hz) were used for subsequent 3-D analyses. The time history of the orientation angles, the initial conditions of the airborne movement, and the BSPs were supplied as the input variables of simulation.;Ten BSP estimation methods in three groups were used: cadaver-based (C), mass scanning-based (M) and geometric (G). Groups C and M consisted of 4 estimation methods each: ratio (C1, M1), simple regression (C2, M2), stepwise regression (C3) or best-fit prediction (M3), and scaling (C4, M4). Group G consisted of two methods: modified Hanavan's (G1) and modified Yeadon's (G2). Seventy-eight anthropometric measures were taken from each subject twice.;Different BSP estimation methods generated significantly different BSPs of all body segments (p...