Fig. 12

Histories of the force and moment components during the VV test at 0° knee flexion. Changes of all the force and moment components during the constrained VV test using CT (a), and unconstrained AP tests using FPH (b), FPA (c) and FPHFM (d). While the constraining forces (AP, PD and LM) and moments (IE) were quite large during CT with RMS values of up to 12.1 N and 0.22 Nm, respectively, their values were greatly reduced during unconstrained tests (b–d). The FPHFM was able to keep the constraining forces and moments close to the measurement accuracy, with RMS values of less than 4.7 N and 0.13 Nm, respectively, and the RMS values of FE angles less than 0.66°. The FPH had RMS values of up to 8.6 N and 0.23 Nm for the constraining force and moment components, respectively. The values for FPA were in between the FPHFM and FPH