The purpose of this pilot study is to compare the dynamic response of microcirculation in the skin on the bottom of the big toe after applying controlled plantar stress in 25 diabetic subjects with a history of foot ulcer and 25 age-matched healthy controls to better understand the role of local hypoxia in neuropathic foot ulceration in subjects with diabetes.

The investigators hypothesize that if they apply a gait simulating load to the plantar foot and measure microvascular function, diabetic individuals will demonstrate an increased delay in reestablishing microvascular flow compared to healthy individuals.

Inclusion Criteria:

• between ages 40 and 75
• history of diabetic neuropathic plantar ulcer (test subjects)
• no history of diabetes (control subjects)
• no peripheral sensory neuropathy (control subjects)

Exclusion Criteria:

• amputation or surgery on right Great Toe

A community sample