Altering Knee Abduction Angular Impulse during Running as a Treatment for Patellofemoral Pain Syndrome: a 6-week Study

INTRODUCTION Patellofemoral pain syndrome (PFPS) is the most common running injury, and is characterized by pain under and/or around the patella during movement [1]. Although no biological cause for PFPS is known, recent biomechanical studies have shown that PFPS may be related to knee joint loading. Specifically, Stefanyshyn et al. [2] found that patients with PFPS experience increased knee abduction angular impulses (KAAI) during running compared to healthy controls. Thus, it is reasonable to propose that a reduction of these KAAIs may have a therapeutic effect for PFPS patients. Recently, Lewinson et al. [3] found that medially and laterally wedged footwear could alter the magnitude of KAAIs during running for healthy subjects. Thus the purpose of this study was to determine if PFPS could be treated by reducing KAAIs during running using wedged footwear. It was hypothesized that subjects who experienced decreased KAAIs would show a greater reduction in pain over a 6-week period compared to those who experienced increased KAAIs.