THE EFFECT OF 2 TYPES OF FOOT ORTHOSES ON REAR-FOOT MECHANICS

Little experimental data exist regarding the comparative biomechanical effects of various loot orthoses. This study evaluated the comparativ e effect of biomechanical orthoses and over-the-counter arch supports on controlling rearfoot pronation. Twenty-four patients with forefoot varus deformity were studied while walking on a treadmill. Two-dimensi onal, videotape motion analysis was used for studying rearfoot mechani cs with three experimental conditions: 1) shoes only, 2) shoes plus ar ch supports, and 3) shoes plus biomechanical orthoses. The variables s tudied were: maximum pronation, calcaneal eversion, maximum pronation velocity, time-to-maximum pronation, and total pronation. No differenc e was noted in maximum pronation, calcaneal eversion, and total pronat ion between the three conditions. The data for maximum pronation veloc ity and time-to-maximum pronation were not reliable. Based on the resu lts of this study, padded arch supports nor biomechanical orthoses can be preferentially recommended for their ability to control maximum pr onation, calcaneal eversion, and total pronation during walking. Addit ional research is necessary to: 1) identify the biomechanical effects that are responsible for the clinical success of foot orthoses, and 2) determine better designs for controlling rearfoot movement.