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Feature

Diane Treat-Jacobson and a study participant

Diane Treat-Jacobson is studying how arm cycling can help people who have difficulty doing lower body exercises.

Arming against leg pain

By Mary Hoff

From eNews, June 26, 2008

Trying to reduce leg pain with an upper body workout sounds a bit like taking cough syrup for athlete's foot. But University of Minnesota assistant professor of nursing Diane Treat-Jacobson is learning otherwise. Her research focuses on peripheral arterial disease (PAD), in which plaque builds up in the arteries of the legs and impedes blood circulation. PAD affects an estimated 9 million people in the United States, including one in five over 70 years of age.

When people with PAD walk or use their leg muscles, oxygen is quickly depleted. This causes muscle pain or cramping that feels like a charley horse. The discomfort keeps many people from exercising, and that leads to a downward spiral of inactivity and further vascular dysfunction. Severe PAD can make it hard to perform the everyday tasks of living, from climbing stairs to grocery shopping.

Until now, the conventional treatment for PAD, ironically, has been using those aching legs.

"Standard exercise therapy requires walking until it hurts, resting for a few minutes until the pain subsides, and then walking again," says Treat-Jacobson. Walking into the pain, she says, trains the muscle to use oxygen more efficiently. Over time, the onset of pain is delayed, and the individual is able to walk a little longer. But it's not surprising that many have a hard time following that prescription with much conviction or consistency.

Might there be a less painful way to make progress against PAD?

While searching for ideas, Treat-Jacobson encountered a British study that compared the effect of stationary bicycling to the effect of "arm cycling"--performing aerobic exercise by rotating a crank with the arms instead of the legs. The study found some improvement in PAD symptoms in both treatment groups. Treat-Jacobson was intrigued by the results, but felt they didn't provide enough information because cycling lacks the weight-bearing component of walking. She received a grant from the American Heart Association to carry out her own research project comparing the effectiveness of arm cycling and treadmill walking in people with PAD.

Treat-Jacobson began by measuring how long her study participants could walk before they began to feel pain and how long they could walk with the pain before it shot up to "5" on her scale--too intense to tolerate. Subjects then went through a 12-week exercise routine that consisted of treadmill walking, treadmill walking plus arm cycling, or arm cycling alone.

Unanticipated findings

Before she started the study, Treat-Jacobson expected that individuals assigned to perform both forms of exercise would have the best outcome. All three groups did show statistically significant gains; participants could walk before the pain stopped them. But when it came to the amount of time they could walk before the pain began, the "arm cyclers" were at least as good, and perhaps even better, than subjects in the other treatment groups. Not only that, but the arm cyclers also showed a decrease in resting blood pressure, while the others did not.

"We were surprised," she says. Treat-Jacobson suspects that walking may cause inflammation in leg muscles that limits the ability to benefit from the exercise. It also may be, she says, that leg pain prevents walkers from reaching the same level of aerobic benefit as the arm cyclers.

In a second study, Treat-Jacobson is now exploring how upper body exercise affects people with more severe forms of PAD--those for whom any use of the legs causes pain, or who experience PAD-related pain at night or when they're at rest. She's measuring the impact of exercise on ability to walk, exercise capacity, perception of pain, and tissue oxygen levels in the feet.

Preliminary results suggest that arm exercises may make a big difference for these patients, too, although the impact varies depending on how severe the problem is.

Treat-Jacobson is excited about the potential of arm cycling to make life better for people with PAD. "Especially for people who are unstable or who can't do lower body exercises, this could be a promising therapy," she says. "I think there are great possibilities to be explored, for example, in long-term care facilities where people worry about falling when performing walking exercise."

As her work gets attention in the popular press, Treat-Jacobson has the rare opportunity to see her research findings reinforced by anecdotal experience. A man with a severe case of PAD sent her an e-mail reporting that after spending a summer doing his own form of upper-body exercise--using a hoe, rake, and shovel from a sitting position in his large garden for 6 to 12 hours per week--he had made tremendous gains in his ability to walk without pain.

"That was very gratifying," says Treat-Jacobson.