Accuracy enhancement of in-vivo bone strain measurements and analysis

A numerical technique is presented to evaluate and correct the zero-strain reference points determined experimentally for certain in-vivo strain rosette applications on long bones. The method is used to determine whether significant transverse stresses are present at the gage site during in-vivo activities. If transverse stresses are shown to be negligible, the experimentally determined zeroes can be appropriately adjusted to provide an increased accuracy of the strain measurements. In addition, the transverse Poisson’s ratio is calculated and can be incorporated in subsequent invivo stress calculations.