The effect of impact on the marrow pressure of long bones in vitro.

Intact fresh sheep tibiae were subjected to non-destructive impact loads while maintained in an environment like that encountered in life. Under a maximum load of 2.5 k N, and loading rate of 500N ms-1, marrow pressures no higher than 50 k Pa were recorded. Such low pressures would provide only a trivial amount of hydraulic strengthening, and are consistent with results from other workers carried out at lower rates of loading.