New study looks at solving the curious case of runner's knee

Whether you are a weekend warrior or a seasoned marathoner, the mere mention of runner’s knee or patellofemoral pain syndrome (PFPS), is enough to make any athlete cringe. Characterized by pain around the kneecap or patella, PFPS makes tasks such as walking up or down stairs arduous and painful.

A new study from the University of Calgary suggests that altering the mechanical loading in the knee joint using orthotic insoles may result in significant pain reduction for those suffering from PFPS. 

“Our aim with this study was to determine if altered knee joint biomechanics would result in improved symptoms for runners who suffer from physician-diagnosed PFPS,” says lead researcher of the study Ryan Lewinson, a PhD student and Vanier Scholar in biomedical engineering and a medical student in the Cumming School of Medicine.

The study, which lasted six weeks was made up of 27 volunteers who were clinically diagnosed with PFPS. Volunteers were divided into two groups, and each were given a different type of orthotic for their shoes. These orthotics were designed to alter their knee joint loads while running.

Reflective markers were placed on the leg with the most painful knee. As volunteers ran, cameras recorded the 3D positions of these markers, and 3D forces were measured at the ground. The data was used to calculate loading in the knee during running.

Custom orthotic insoles can further reduce pain 

“What we found was that regardless of which orthotic volunteers received, there was a relationship between change in biomechanics induced by the orthotic, and change in pain over the six-week period," says Lewinson.

"Specifically, those who experienced large changes to knee loading tended to experience larger reductions in pain, whereas those experiencing just small biomechanical changes tended to only experience small or no reductions in pain.” 

Although previous studies have shown that orthotic insoles can reduce pain, Lewinson believes they can be fine-tuned to the point of developing custom orthotics based on an individual’s characteristics.

“If we can figure out ways of predicting someone’s biomechanical response without needing a specialized biomechanics lab, we may one day be able to match the right intervention with the right person to optimize treatment of PFPS on a patient-by-patient basis.”

The University of Calgary's research priority in Engineering Solutions for Health: Biomedical Engineering is focused on better disease and injury prevention, diagnosis and treatments. These disciplinary advances are also applying systems engineering principles to continuously improve the health system.