Uncertainty in marker placement relative to anatomical landmarks expressed in opensim coordinate systems (based on Della Croce et al. [32]). Bold stds represent anatomical landmarks directly investigated in Della Croce et al. Nonbold stds were selected according to the anatomical plane that best represents the surface tangent to the anatimical landmark. Along the two directions of this plane, a std of 7.9 mm was used (average of maximum stds in Della Croce et al.). Along the direction perpendicular to the same surface, a std of 3.7 mm was used instead (average of minimum stds in Della Croce et al.).
