OBJECTIVES: The aim of the study was to estimate the functional contribution of the arterial inflow pathways to the pelvic circulation, during walking, in patients with stage 2 lower extremity arterial disease. BACKGROUND: Transcutaneous oxygen pressure (tcpO2) changes during exercise can be used to estimate the severity of regional blood flow impairment while walking. METHODS: Seventy patients with stable lower limb claudication were studied using a multi-variante linear regression model . The relationship between exercise-induced buttock tcpO2 changes ,the ipsilateral calf tcpo2-changes and the arterial diameters of the pelvic arteriographic pathways were analazed. RESULTS: The ipsilateral hypogastric and lumbar pathway, as well as the ipsilateral calf tcpo2-changes were the only variables significantly related to buttock tcpO2-changes (r=0.47; p<0.001). Their normalized respective contribution to the regressive model was 39, 19 and 18 % respectively. None of the contra-lateral hypogastric, mesenteric and sacral pathways or pathways stemming from the external iliac artery, showed significant correlation to buttock tcpO2-changes. CONCLUSIONS: The ipsilateral hypogastric and ipsilateral lumbar pathways are the major pathways responsible for the functional buttock blood flow supply during walking. The role of contra-lateral hypogastric, inferior mesenteric and median sacral pathways and arteries distal to the internal iliac trunk is negligible in the normal or compensatory blood flow supply. Distal tcpo2 decrease at exercise aggravates proximal tcpO2 decrease, possibly through the occurrence of a "steal phenomenon" of distal over proximal circulation during walking.