Diminished walking capacity is a hallmark activity limitation of people with Peripheral Artery Disease (PAD). The ankle has the greatest joint torques during walking with large associated energy demands of the calf musculature. The combination of blockage of blood flow with PAD and the physical exertion of the calf musculature during walking creates claudication symptoms of pain, aching, or burning in the lower leg. Claudication symptoms can be an important rate-limiting factor in the effectiveness of walking exercise programs for people with PAD. We have completed a pilot trial that shows promising results for the use of carbon-fiber ankle foot orthoses (AFO) to ease patients’ claudication symptoms during walking with improved walking ability. Trial participants completed instrumented video analysis of their walking with concurrent electromyography of the ankle plantar flexors both before and after their 12-week walking program using the AFO. How the AFO alters walking mechanics for our participants, especially at the ankle joint and calf musculature will be the focus of the current presentation. Discussion will include clinical interpretation of the results and their potential implications within patient care.