The influence of patellofemoral pain on lower limb loading during gait.

OBJECTIVE: To determine if subjects with patellofemoral pain demonstrate excessive lower limb loading during gait.
DESIGN: Prospective study utilizing a group of patients with patellofemoral pain and a control group.
BACKGROUND: Increased rate of lower limb loading has been hypothesized as being contributory to knee osteoarthritis and may be the result of decreased knee flexion during weight acceptance. Since patients with patellofemoral pain have been reported to limit knee flexion during gait, these individuals may be at risk for the adverse effects of impulse loading.
METHODS: Force plate parameters, lower extremity kinematics and stride characteristics were recorded in 15 females with patellofemoral pain and 10 pain-free controls during self-selected free and fast walking velocities.
RESULTS: Individuals in the patellofemoral pain group demonstrated a significantly slower gait velocity during the free and fast trials as well as decreased stance phase knee flexion during fast walking. The average peak loading rate for the patellofemoral pain group was significantly less than the control group during both free (P=0.004) and fast walking (P=0. 03).
CONCLUSIONS: Despite diminished stance phase knee flexion during fast walking, subjects with patellofemoral pain did not demonstrate increased lower limb loading. During gait, the ground reaction forces appeared to be minimized by adopting a slower walking velocity. RELEVANCE: These results indicate that altered knee kinematics as a result of patellofemoral pain do not place these individuals at risk for the adverse effects of impulse loading.