Fig 1.
One showing the anteroposterior (AP) dimensions of the inlet, midplane, and outlet, and the other showing the mediolateral (ML) dimensions of the inlet, midplane, and outlet.
Table 1.
Descriptive statistics for study sample.
Fig 2.
Eleven landmarks, shown as red circles, were taken on 3D models of pelves to represent the canal. One pelvis is shown here from the anterior, lateral, and inferior points of view.
Table 2.
Landmark descriptions.
Table 3.
Canal measurements.
Table 4.
Summary of regression results.
Table 5.
Relative importance of predictor variables on canal shape and dimensions.
Fig 3.
Relationship of inlet shape with gut volume.
Regressions between gut volume and pelvic canal shape at the inlet relative to body mass. The male sample (left, green) shows a significant relationship. To visualize the effect of body mass on the variables, the plots shown here separate the data points into three groups: those with body masses below 1 SD from the mean (lightest color), those with body masses above 1 SD from the mean (darkest color), and those with body masses between -1 SD and +1 SD from the mean (medium color). The regression lines are the best fit lines for each group.
Fig 4.
Relationship of midplane shape with gut volume.
Regressions between gut volume and pelvic canal shape at the midplane relative to body mass. Both the male and female samples (right, orange) show significance.
Fig 5.
Relationship of ischial spine and S5 position with gut volume.
Regressions between gut volume and (A) ischial spine projection (θa) and (B) S5 apex position (θb) relative to body mass. A lower θa indicates more medially-projecting ischial spines. A higher θb indicates a longer distance between the ischial spines and the S5 apex. The left column (green) represents the male sample and the right column (orange) represents the female sample. Only the female regression models were significant.
Fig 6.
Relationship of outlet shape with gut volume.
Regressions between gut volume and pelvic canal shape at the outlet relative to body mass. Only the female sample (right, orange) shows a significant relationship.