This is Dr. David
I am sorry you are having bad circulation and claudication pain behind the knees.
I assume you have had ultrasounds of your leg to show your poor circulation and claudication and this is what is causing the pain
and that you are getting your high blood pressure and high cholesterol and diabetes treated as best as possible with medication
are you stretching before and after walking? this is important to warm up the muscles.
also make sure your potassium levels are not low, low potassium can also cause muscle and calf pain.
Cilostazol is the most effective medication for treatment of claudication symptoms, particularly when combined with exercise
are you on cilostazol? also called Pletal?
circulation machines are not proven and don't really help move blood through your narrowed and damaged blood vessels.
a number of studies have suggested that ginkgo biloba may improve symptoms of claudication as well. you can try this which is over the counter.
let me know if you have other questions.