A prospective study on gait-related intrinsic risk factors for patellofemoral pain

OBJECTIVE: To prospectively determine gait-related risk factors for patellofemoral pain. DESIGN: A prospective cohort study. SETTING: Male and female recruits of the Belgian Royal Military Academy during a 6-week basic military training period. PARTICIPANTS: Eighty-four officer cadets (65 men, 19 women), who entered the Military Academy and were without a history of any knee or lower-leg complaints, participated in the study. INTERVENTIONS: Before the start of the 6-week basic military training period, plantar pressure measurements during walking were performed. During the basic military training period, patellofemoral complaints were diagnosed and registered by a sports medicine physician. MAIN OUTCOME MEASUREMENTS: Plantar pressure measurements during walking were performed using a footscan pressure plate (RsScan International). RESULTS: During the 6-week training period, 36 subjects developed patellofemoral pain (25 male and 11 female). Logistic regression analysis revealed that subjects who developed patellofemoral pain had a significantly more laterally directed pressure distribution at initial contact of the foot, a significantly shorter time to maximal pressure on the fourth metatarsal, and a significantly slower maximal velocity of the change in lateromedial direction of the center of pressure during the forefoot contact phase. CONCLUSIONS: Our findings suggest that the feet of the persons who developed anterior knee pain have a heel strike in a less pronated position and roll over more on the lateral side compared with the control group. The results of this study can be considered valuable in identifying persons at risk for patellofemoral pain.