Figure 2

Loading on a hip prosthesis. (a) single force $\overrightarrow{R}$ on the head (b) equivalent combination of force $\overrightarrow{R}$ and moment $\overrightarrow{M}$ on the stem. If $\overrightarrow{R}$ is considered as a vector with three components (R_x, R_y, R_z), $\overrightarrow{M}$ would cause torque around the three axes and is represented by double-arrow-headed vector components (M_x, M_y, M_z). In this study, only M_z was considered.