It also explains why fractures caused by shear stress often occur with minor trauma. Lateral humeral condylar fracture in a four month old Cocker Spaniel 4. Bending When bending forces are applied to a bone, tensile forces are generated on the convex surface and compressive forces are generated on the concave side. A continuous gradient of stress distribution from tension to compression exists through the bone's cross section. Bones which are eccentrically loaded such as the femur are subjected to physiologic bending forces.
Fractures produced by bending forces are commonly transverse or short oblique.
These types of fractures are commonly seen in the diaphyseal regions of long bones. Torsion Torsional loading is a variation of shear loading and occurs as the result of rotational forces applied to a structure's long axis. The mechanics of torsional failure are complex and are a combination of shear, compressive and tensile forces. The resultant fracture typically is a long oblique spiral fracture.