Title Atypical Pronation of the Sub-Talar Joint: Its Implications on the Lower Limb Background Atypical pronation of the sub-talar joint, or overpronation of the foot, as it is more commonly known, is a current subtopic in foot and lower limb-related biomechanical issues. Typical pronation is a tri-planar movement that involves eversion of the hindfoot, combined with abduction and dorsiflexion of the forefoot. Atypical pronation is recognized when this motion is excessive, and may be determined by the extent and duration to which this occurs according to the rhythmic timing during the gait pattern. It is a mechanical problem of the foot that primarily results from a subluxation or shift of the sub-talar joint and bones of the mid- and hind-foot. As a common finding in the general population, especially in those with flexible flat feet, atypical pronation may result chronically in a displacement of the bones and joints of the lower limb. Research has stated that excessive pronation of the ankle-foot complex may cause change in position of certain bones in the lower limb. This is believed to occur through an interaction between foot and pelvis through a kinetic chain mechanism. Furthermore, it has been stated that atypical pronation may affect weight transfer of the lower limb during gait that may...