By Steve Weakley
Specially designed “space pants” worn by astronauts to regulate their body temperature are helping patients with Peripheral Artery Disease (PAD) walk and exercise again with less pain.
More than eight million Americans suffer from PAD -- a narrowing of peripheral arteries in the legs that can cause severe pain and cramping after a short walk or even just climbing a flight of stairs.
“I have patients that have trouble going to their mailbox,” said Bruno Roseguini, PhD, an assistant professor in the Department of Health and Kinesiology at Purdue University. “These patients, in order to avoid that pain, become very inactive. So, this is a vicious cycle that leads to more impairment and more functional decline over time.”
To get PAD patients moving again, Roseguini and his research team turned to NASA and the elastic space pants worn by astronauts. Woven into the pants is an elaborate tubing system that circulates warm water and helps keep the astronauts’ body temperatures normal in a weightless environment.
Researchers modified the pants for a clinical study of PAD patients and found they were able to lower blood pressure and increase circulation in their legs. Patients who wore the pants for 90 minutes every day for eight weeks reported less pain and more mobility.
"It's like putting your legs in a hot tub without getting wet," says PAD patient Stephen Scott, who is now able to stand longer and walk longer distances. "It feels good."
“Based on our initial findings, it is conceivable that repeated exposures to heat therapy might enhance the ability of the arteries in the legs to vasodilate” Roseguini said. “What that means is there would be more blood flow and greater oxygen delivery to calf muscles during exercise, and we anticipate this will prolong the time they can walk before they feel pain.”
Roseguini explains how the pants work in the video below:
Roseguini calls physical exercise the “gold standard” for treating PAD, even if many patients choose other routes of relief. Some have stents surgically inserted into their leg arteries, but they can narrow without exercise and may have to be replaced every few years. Medication and dietary changes can also help manage PAD, for which there is no cure.
“Exercise is painful for these patients and leg pain is one of the main reasons for why most of these patients do not adhere to structured exercise programs,” said Roseguini. “Heat therapy, on the other hand, is not painful. If anything, heat therapy might actually reduce leg pain, so the patients see that as a treatment they would potentially adhere to.”
Studies show heat therapy can also improve the health of blood vessels and help muscles recover after an injury.
“Heat therapy is a powerful tool for rehabilitation,” says Roseguini, who hopes to develop a portable battery-powered pump that PAD patients can wear without being tethered to an electric outlet. “I want the patients to be able to receive the therapy while walking and performing their daily living activities, such as going to the grocery store.”