Although each loading mode has been considered sepa- rately, living bone is seldom loaded in only one mode.The shear stress was low throughout the stride, denoting minimal torsional loading produced by slight external and internal rotation of the tibia in an alternat- ing pattern.In vivo measurement of the strains on the anteromedial surface of a human adult tibia during walk- ing and jogging demonstrates the complexity of the load- ing patterns during these common physiologic activities (Lanyon et al., 1975).Stress values calculated from these strain measurements by Carter (1978) showed that during normal walking, the stresses were compressive dur- ing heel strike, tensile during the stance phase, and again compressive during push-off (Fig.During jogging, the stress pattern was quite differ- ent (Fig.2-32A).