Figure 3: Required elements for misalignment compensation in three dimensions. The misalignment compensation mechanism of any of the rotational DOFs consists of the sliders perpendicular to the rotation axis. For flexion/extension (F), movement of sliders 2 and 3 is required; for internal/external rotation (R), sliders 1 and 3; and for abduction/adduction (A), sliders 1 and 2.