Effects of Hormonal Conditions and Drugs on Both Muscle and Bone Strength Can Be Assessed in a Single Rat Test

Strength of both muscles and bone are important for fracture prevention in osteoporotic individuals. Therefore, drugs that are preclinically tested in animals for preventing or treating osteoporosis, and reducing fracture risk, should not only be checked for their effects on bone strength, but also for those on muscle strength. We developed a rat model to measure both in the same animal, using a single test. The model is based on an in vivo, ventral three-point bending test of the lower leg (Nordsletten L. and Ekeland A. J Orthop Res 11:299–304; 1993). This model was developed to test the contribution of triceps surae muscle contraction to the strength of the tibia. We hypothesized that this same test can be applied to determine bone and muscle strength indepen-dently, in an absolute sense. To investigate this possibility, the muscle contribution to bone stresses was estimated fro