Figure 1.

Frontal plane knee angle (figure a) and angular velocity (figure b) curves during the first 60% of gait cycle (mainly stance phase of walking) in knees with visually observed varus thrust (red line) vs. knees without thrust (black line). Varus is in the positive direction. Solid lines represent the ensemble averages and shaded areas represent ± one standard deviation around the average values. The initial knee position at the beginning of stance was normalized to “zero” for ease of comparison. In the varus thrust positive group, the maximum knee varus angle occurred near the beginning of the mid stance phase for the ensemble average curve, and remained near the maximum throughout the entire mid stance phase, eventually returning to baseline at the end of stance. Note the corresponding greater increase of knee varus angular velocity. It is important to point out that each knee’s peak varus angle and angular velocity occurred at a slightly different time point during the early to mid stance phase of gait, and thus averaging these magnitudes at each time point likely will attenuate the individual knees’ peak values. Nonetheless, the general trend of greater knee varus angle and angular velocity is evident in knees with a varus thrust compared to knees without a varus thrust.