Biomechanical changes are one factor causing PFPS. Excessive pronation is a common aetiology of AKP. Due to rear foot eversion in gait, the foot pronates rapidly after heel strike (Barton et al., 2011) resulting in excessive subtalar joint pronation. Before the patient is fitted with orthotics, general measurements are recorded. These include; ankle and knee range of motion and leg length discrepancy, to ensure there are no other major biomechanical factors creating excessive subtalar joint pronation (Rodgers et al, 1982). The aim of an orthotic is to allow a normal amount of pronation to occur through the gait cycle, however, stop any excessive movement (Johnstone, & Gross, 2004). To do so, the orthotic will put the subtalar joint into neutral
