Movements in Pilates exercises are controlled — sometimes moving the body only inches — but those small motions are making a big difference to some people with Parkinson's disease.

No research has been done to prove Pilates' effectiveness in reducing Parkinson's symptoms, but a growing number of patients say they are finding some relief.

"I love it, it's great," said Karen Smith, 62. "It exercises muscles that otherwise don't get exercised."

Parkinson's, a degenerative disorder, inhibits a person's ability to control movement. Its most common symptoms include tremors, slowness of movement, rigidity and poor balance.

Smith is part of a group that meets twice a week at the Parkinson Center of the Oregon Health and Science University in Portland. The center held a Pilates pilot program earlier this year, and after it found improvement in the participants' rigidity and balance it launched a twice-weekly class open to the public.

The center already has a waiting list for its next round of classes.

A few Pilates instructors elsewhere around the country also are offering classes specifically for people with the disease.

"It could be any exercise" that might help people, said Kristi Sesso, owner of the Harmony Group Pilates and Gyrotonics studio in Englewood, N.J. "But Pilates is a great point of access."

Instructors say the basic principal of Pilates — increasing core strength and improving flexibility and balance — is extremely helpful in countering the effects of Parkinson's in some people.

"I never dreamed of trying to do Pilates or anything like that," said Greg Moore, 59, who was diagnosed with Parkinson's 17 years ago and just started practicing Pilates. "Now I realized how stiff and boxed up I am."

There are studies that show exercise can ease the severity of Parkinson's symptoms, said Michael S. Okun, national medical director for the National Medical Foundation. However, it needs much further research, he said.

"I tell my patients that exercise is like a drug — if they exercise religiously or stretch religiously, they do great," Okun said.

Pilates participants say the exercises aren't a strain, which makes the program more approachable for patients who don't exercise at all. Additionally, they say, it's supportive to be in a positive environment with other people with Parkinson's.

Many Parkinson's patients struggle with depression and some say the exercise has helped them.

"A lot of times exercise is as much for the head as it is for the body," said John White of Corvallis, Ore. "To feel like you can help yourself in some way is really important."

White, a former track and wrestling coach, says Parkinson's is a "seven-day-a-week job." But he says he exercises religiously and it allows him to continue hiking, golfing and running.

Debi LaVietes Clark, owner of Body Balance Pilates where White practices, says she is seeing an increasing number of people brought in by participants who have described how the program helps with flexibility, agility and balance.

"But what I've noticed, first and foremost, is confidence," Clark said. "Just because you are diagnosed with a disease doesn't mean the end of the world."