Analysis of relative motion between the socket and residuum in individuals with lower limb amputation

A new variable stiffness torsion adapter for a lower limb prosthesis was developed to reduce soft tissue shear stress in the residual limb by reducing transverse plane stiffness during activities of daily living. However, direct measures of shear stress are challenging due to the inability to optically resolve the relative motion between the socket and shank of the residual limb. Previous work has utilized the peak transverse plane moment as an indirect measure to indicate induced shear stress. This work uses an inverse kinematics analysis to estimate the relative motion between the socket and residual limb and determine if that motion is correlated with the direct measure of transverse plane moment at the socket interface.