Anatomical and biomechanical analyses of the unique and consistent locations of sacral insufficiency fractures - Linstrom, NJ; Heiserman, JE; Kortman, KE; Crawford, NR; Baek, S; Anderson, RL; Pitt, AM; Karis, JP; Ross, JS; Lekovic, GP; Dean, BL (Spine (Phila Pa 1976), 2009)