Gait-related intrinsic risk factors for patellofemoral pain in novice recreational runners.

OBJECTIVE: To determine prospectively gait-related intrinsic risk factors for patellofemoral pain (PFP) in a population of novice recreational runners.

DESIGN: Prospective cohort study.

PARTICIPANTS: 102 novice recreational runners (89 women) with no history of knee or lower leg complaints.

INTERVENTIONS: The standing foot posture of the subjects was examined and plantar pressure measurements during running were collected. The subjects then participated in a 10-week "start to run" programme. During this period all sports injuries were registered by a sports medicine physician.

MAIN OUTCOME MEASUREMENTS: The relationship between the standing foot posture and PFP was investigated and gait-related intrinsic risk factors for PFP were determined.

RESULTS: The 17 runners who developed PFP exerted a significantly higher vertical peak force underneath the lateral heel and metatarsals 2 and 3. Logistic regression analysis showed that a significantly higher vertical peak force underneath the second metatarsal and shorter time to the vertical peak force underneath the lateral heel were predictors for PFP. No significant evidence was found for an association between an excessively pronated or supinated foot posture and the development of PFP.

CONCLUSIONS: The findings suggest that an excessive impact shock during heel strike and at the propulsion phase of running may contribute to an increased risk of developing PFP. The hypothesis that persons at risk for PFP show an altered static foot posture in comparison with non-afflicted persons is not supported by the results of this study.