Grant: Travel Awards - Institute Community Support

Patellofemoral pain syndrome (PFPS) is the most common running injury, characterized by pain beneath and around the knee-cap during movement. Runners with PFPS experience larger mechanical loads in the knee joint during the stance phase of running compared to uninjured runners. It has been proposed that these greater loads induce greater stress within the joint, thereby increasing pain. If this is the case, one might suspect knee load magnitude and pain severity to be related. In this study, 35 runners with diagnosed PFPS reported pain during running on a scale from 0-100. Then, each runner completed 5 trials running along a runway in a biomechanics laboratory where 3-dimentional leg movements were measured using an 8-camera system, and the forces exerted on the ground during running were measured using a force platform. Combining the movement and force data, knee joint loads were calculated. Statistical analysis revealed that knee joint loading magnitude was not related to pain severity. Based on this result, it is believed that rather than increasing stress at a given location within the knee, which would lead to greater pain, greater knee loads shift the knee-cap to a new location, inducing new mechanical stress and pain, which is then perceived differently for different patients. This theory is currently being investigated using animal models.