Your next patient is a 67 year-old male who presents for painful right foot. He notes that the foot hurts more with ambulation than with rest, although he sometimes dangles the foot off the edge of the bed to help decrease the symptoms. He denies trauma. On physical examination, his feet are both slightly cool, but the right more so than the left. A palpable pulse on the right is present but thready. He has no erythema, no significant swelling, and no tenderness to palpation.