The biomechanics of patellofemoral pain syndrome in distance runners

Patellofemoral pain syndrome (PFPS) is the most common injury in runners. This thesis investigates the theory that prolonged eversion at the rear-foot causes prolonged tibial internal rotation and excessive femoral internal rotation, and predisposes female, distance runners to PFPS. Since eversion occurs at the subtalar joint, the morphology of the talus and calcaneus were also assessed. The study was a case-control investigation between female runners with a history of PFPS (n = 9) and normal controls (n = 10). Gait analysis was used to measure lower-limb joint angles during barefoot, treadmill running. It was hypothesised that runners with PFPS would demonstrate prolonged rearfoot eversion and tibial internal rotation, and increased hip internal rotation compared to normal controls. Computed tomography was used to image the foot and ankle in simulated weight-bearing using a custom-built loading rig. Three-dimensional models of the talus and calcaneus were generated and their shapes were quantified using principal axis lengths and orientations. The results did not support the theory that prolonged eversion and rear-foot structure predispose to PFPS during running, and attributing PFPS to these factors should be done with discretion. However, runners with a history of PFPS exhibited increased rear-foot eversion, reduced rear-foot dorsiflexion and increased knee internal rotation compared to normal controls during running, walking and squatting. Subjects with PFPS also demonstrated increased dorsiflexion at the mid-foot. It was proposed that increased eversion was secondary to reduced rear-foot dorsiflexion as this enabled compensatory dorsiflexion at the mid-tarsal complex. Due to the tight articulation of the ankle mortise, increased knee internal rotation corresponds well with excessive rear-foot eversion. A prospective study is required to establish whether these kinematic alterations are a cause or an effect of PFPS.EThOS - Electronic Theses Online ServiceGBUnited Kingdo