The effects of walking speed on forefoot, hindfoot and ankle joint motion

Abstract Background Foot and ankle joint kinematic differences have been identified between healthy subjects and subjects with various pathologies suffering from foot and ankle impairments. Changes in temporal factors such as walking speed and double stance time are also found in these pathological conditions. As such, in theory, these factors would also influence the kinematics and hence make it difficult to ascertain the effects of the disease on the kinematics. The aim of this study was to analyse foot and ankle kinematics from gait recordings of healthy subjects walking at comfortable and slower speeds. Methods Gait patterns of 14 healthy subjects were recorded. The subjects were first asked to walk at a comfortable speed and then at predefined speeds of 75% and 50% of their comfortable walking speed respectively. Temporal variables were calculated. Foot and ankle joint kinematics were determined from marker-recordings. Findings The subjects walked at mean velocities of 1.28 m/s, 0.97 m/s and 0.65 m/s. With decreasing walking speed the minimum tibio-talar plantar-flexion and maximum hallux dorsi-flexion at toe-off decreased significantly between 3° and 9°. The minimum medial arch at toe-off and minimum midfoot supination at mid-stance were significantly affected by the walking speed. The corresponding individual session differences were small (1°–2°), but the reliability was high and hence the differences were considered clinically relevant. Interpretation Walking speed significantly affected foot and ankle kinematics. Studies aiming to improve the understanding of the effects of foot and ankle pathologies on foot and ankle kinematics should take the walking speed into account.