5. Stresses in Torsion

Sandra Snowflake, an X-ray technician at Mega General Hospital, spent most of her spare time either in the gym or in the park running. Thus she was in excellent physical shape. Her major reason for staying in shape was her love of skiing, and she worked and lived for the three separate weeks she took for ski vacations in Colorado. This year spring skiing was exceptionally good, and she was at the top of her form, schussing down the black diamond runs with ease. Unfortunately, the new bindings she was getting used to had not been adjusted exactly right, and she knew immediately —when she hit the icy patch and lost control of her outside ski—that her leg was broken. This was confirmed at the small hospital at the base of the slope where she was taken by the ski patrol. When Dr. Fromm showed her the film of her leg, her experienced eye recognized a spiral fracture of the tibia. Why does torsion create a tibial fracture?