Grant: Travel Awards - Institute Community Support

Running injuries frequently occur that can impair one's ability to be physically active. Most commonly (about 1.5 million Canadians per year), runners will develop a chronic condition known as patellofemoral pain syndrome (PFPS), which is characterized by pain under and/or around the knee cap during running, sitting, and stair climbing. Therefore, PFPS can severely affect the individual's well-being throughout their daily life. Although no biological cause for PFPS is known, recent advances in engineering have shown that PFPS may be related to increased mechanical loading in the knee joint during running. In the present study, it was hypothesized that pain could be reduced for runners with PFPS by decreasing knee joint loads using a biomechanical footwear intervention. Thirty runners with PFPS volunteered for the study. Each runner provided baseline pain measurements and then were tested in a biomechanics laboratory running with 3 different shoe conditions: (1) a neutral shoe, (2) a neutral shoe with a medially wedged orthotic insert (medial side of foot elevated relative to the lateral side) and (3) a neutral shoe with a laterally wedged orthotic insert (lateral side of foot elevated relative to medial side). Each runner was given one of the two wedge conditions to use during their runs for 6-weeks and pain during running was continuously monitored. Following the 6-weeks, statistical analyses were conducted to determine if a relationship between decreased joint loading and decreases in pain existed. Results indicated that runners who experienced the greatest absolute change in knee joint loading (regardless of increase or decrease) experienced the greatest reductions in pain. Thus a goal for future clinical practice may be to alter joint loading to achieve maximal treatment benefits. More research is needed to understand the reason why both increases and decreases in joint loading can produce similar results.