This subject was a 61 year old male with type II diabetes. As a result of an unhealed neuropathic foot ulcer, he had a right transtibial amputation 8 yr prior. He was 163 cm tall and 99.5 kg mass and a K-2 level ambulator, using his prosthesis at least 12 h/day. He regularly used a PTB endoskeletal prosthesis with a gel liner and lock-and-pin and a Fusion Foot (Ohio Willow Wood). His skin was thin and fragile with poor sensation, and in the past he had blisters and wounds on his residual limb. He did not typically add socks during the day to accommodate residual limb volume reduction, though the research practitioner considered this practice a reflection of his neuropathy. She believed that he did not sense his limb volume reduction and the need to add a sock. He underwent bioimpedance testing with his regular prosthesis first. He was then fitted with a new socket equipped with a P2 Harmony unit and Seattle Lightfoot (TrueLife). He used this prosthesis exclusively for 3 wk prior to bioimpedance testing.