Figure 4

Patterns of the six knee kinematics components obtained after applying the selected pose estimators to a 4-marker cluster (a) and to a 12-marker cluster (b) when only instrumental errors were added to the marker nominal positions. Nominal patterns: thick gray lines; estimates from the geometric pose estimator: thin gray lines; estimates from the SVD-based pose estimator: thin black lines; estimates from the PCTu pose estimator: thick black lines; estimates from PCTa pose estimator: dotted black lines.