This subject was a 54 yr old male who had a transtibial amputation 4 yr prior as a result of traumatic injury. His residual limb was 23 cm in length, conically-shaped, with good hair and sensation. He had a distal neuroma removed 4 mo prior to biompedance testing. He was 188 cm in height, 77 kg in mass, and a K-3 level ambulator. He used his prosthesis for approximately 16 h/day. He had a history of smoking and high cholesterol and had been diagnosed with peripheral arterial disease and peripheral vascular disease. He had pain in his calf when ambulating more than two blocks. Because of volume fluctuation problems in his limb, he typically added socks during the day. In an effort to enhance suspension and reduce volume fluctuation problems, 4 wk prior to bioimpedance testing his regular prosthetist switched him from a PTB endoskeletal prosthesis with a gel sock, Pelite liner, and neoprene suspension to a manual elevated vacuum system (P2 Harmony). He used this manual elevated vacuum socket during bioimpedance testing, with a dynamic response Flex Foot (Ossur).
Cases #5 and #6 both used electronic vacuum systems for short term intervals, approximately 4 wk. However, Case #6 used the electronic vacuum unit regularly outside the lab, while subject Case #5 used it intermittently. Both subjects had excessive redundant soft tissue in their residual limbs, particularly distally.