PREDICTION OF HUMAN SEGMENT INERTIAS DURING PREGNANCY

The purpose of this study was to develop prediction equations to estim ate mass, radius to the center of mass (CM), and principal moments of the segments during pregnancy. Nonlinear regression equations were det ermined for the lower trunk, upper trunk, and thigh. The third samplin g month of a longitudinal study was used (Sample 1, n = 15). The nonli near regressions were then used to predict segment inertias above and below the third sampling month (Sample 2, the remaining 74 measurement s). For the remaining segments, body mass and segment lengths were use d as predictor variables for mass, radius to CM, and radius of gyratio n about the centroidal axes. The remaining seven segments did not chan ge substantially during pregnancy, and the means of the repeated measu res were used for the simple linear regressions. Eighteen of the 28 re gressions and all of the CM regressions were significant. With pregnan t subjects it is recommended that these regressions be used if applica tion of the elliptical cylinder model is not possible.