Figure 4

Influence of the quadriceps force level on patellar displacement. Patellar mediolateral shift (top) and tilt (bottom) during lateral (a) and medial (b) force application are illustrated, comparing the four measured levels of quadriceps force (30, 150, 300, 600 N). Mean values and standard deviations are shown for 50 N of mediolateral patellar displacement force and central quadriceps force distribution.