Figure 9. Principal stress trajectories for the proximal femur in the solution posture of ‘Troodon’, compared with observed cancellous bone fabric.

(A and B) Vector field of σ₃ in the femoral head, shown as 3-D slices parallel to the coronal plane (A, in anterior view) and sagittal plane (B, in medial view). (C and D) Observed vector field of u₁ in the femoral head, in the same views as (A) and (B), respectively (cf. Part I). (E) Comparison of the mean direction of σ₃ in the femoral head (blue) and the mean direction of u₁ (red), plotted on an equal-angle stereoplot with northern hemisphere projection. Inset shows location of region for which the mean direction of σ₃ was calculated. (F and G) Vector field of σ₃ under the greater trochanter, shown as 3-D slices parallel to the coronal plane (F, in posterior view) and sagittal plane (G, in lateral view). (H and I) Observed vector field of u₁ under the greater trochanter, shown in the same views as (F and G), respectively (cf. Part I). (J) Vector field of σ₁ in the lesser trochanter, shown in oblique anterolateral view. (K) Observed vector field of u₁ in the lesser trochanter, shown in the same view as (J) for both specimens studied (cf. Part I).