A home exercise program for tibial bone strengthening based on in vivo strain measurements

Objective: To compare the strain and strain rates generated during lower limb calisthenics with walking, an exercise that has been found to have only minimal effect on bone mass. Strengthening of bone, while it still has adaptive ability, can be achieved by exercise. Mechanical loading during physical activity produces strains and strain rates within the bones. It is thought that strain and strain rates higher than the usual provide the stimulus for the bones' adaptation. Design: Three strain-gauged bone staples were inserted percutaneously in a 30° rosette pattern in the medial aspect of the midtibial diaphysis of two volunteers. The principal compression, tension, shear strains, and strain rates were measured during various lower limb calisthenics and compared with those of jogging and walking. Results: Zig-zag hopping was in the grouping of exercises with the highest principal compression, tension, and shear strains and compression strain rates, whereas walking was in the lowest or next-to-the-lowest grouping for all principal strain or strain rates. Conclusion: Zig-zag hopping, based on the high strain and strain rates that it produces, may be an optimal tibial bone-strengthening exercise.