Bone strain and bone formation.

<p>(A) Mean distribution of peak longitudinal normal strain (µε) across the tibial mid-diaphysis during treadmill exercise. The neutral axis (NA) is dashed with compressive and tensile strain isopleths plotted parallel to it. Maximal compressive strains (negative sign) were produced on the posterior shaft surface, and maximal tensile strains were produced on the anterior shaft surface. (B) Tibial midshaft cross section subdivided into 16 equal-angle sectors positioned about the neutral axis, with the axis orthogonal to the neutral axis projected through the area centroid. (C) Distribution of periosteal bone added in exercised animals and sedentary controls during the experimental period (means + SD). Asterisks indicate statistically significant (<i>P</i><0.05) differences between exercised animals and controls as determined by two-sample Wilcoxon tests. Numbers indicate percent difference between the mean of the exercised animals relative to the control mean.