Adequate blood flow to the skin is necessary for healthy, viable tissues. Adequate skin perfusion requires four factors:
1. The heart must be able to pump adequately
2. The volume of circulating blood must be sufficient
3. Arteries and veins must be patent and functioning well
4. Local capillary pressure must be higher than external pressure
-Leg and foot ulcers occur from various causes, but the most common are ulcers secondary to venous insufficiency, arterial insufficiency and neuropathy. Impaired arterial or venous function in the lower extremities can produce ulcerations that are refractory to healing unless the underlying disorders treated.