This study characterized a non-invasive method of applying mechanical strain to the tibiae of rats. A four-point bending device was used to induce mechanical strain non-invasively in an 11 mm section of the right tibiae of 10 female Sprague-Dawley rats. Induced strains were measured in vivo at various locations along the rat tibia to establish a relationship between induced strain and applied load. Finite element analysis was used to quantify the magnitude of shear stresses in the rat tibia due to four-point bending. The in vivo measured strains were highly correlated with the calculated strains using beam bending theory (r2 = 0.87). The finite element model predicted shear stresses to be less than 10 percent of the longitudinal stresses resulting from the four-point bending.