The strains developed within the skeleton during normal activity can be measured by strain gauges, and used to calculate functional bone loads in vivo. However, since the remodelling processes responsible for bones' architecture are influenced by their current loading situation, these strains also represent a structural objective. Experiments in which bone strain levels have been recorded and manipulated in vivo indicate that this structure:​ function relationship is not uniform, since levels and distributions of strain which are acceptable in one location will induce adaptive remodelling in others, and vice versa. The potential of a dynamic strain regime to induce new bone formation is more strongly related to the rate of change of strain during each loading cycle than the peak magnitude of strain achieved. The maximum osteogenic effect of an intermittent strain regime can be achieved by as few as 36 consecutive loading cycles per day. Additional strain reversals produce no increase in the amount or character of new bone formation.