Because of knee arthritis, many older adults find walking, climbing stairs or even getting up from a chair difficult. But these study findings equate walking more with better everyday functioning.
"People with or at risk for knee arthritis should be walking around 6,000 steps per day, and the more walking one does the less risk of developing functioning difficulties," said the study's lead author, Daniel White, a research assistant professor in the department of physical therapy and athletic training at Boston University.
Every step taken throughout the day counts toward the total, he said. The key is to wear a pedometer and take up to 6,000 steps daily, he said.
"People usually average 100 steps per minute while they walk, so (6,000 steps) is roughly walking an hour a day," White said. "It doesn't seem to make a difference where the steps come from."
For someone with knee arthritis who is just starting to exercise, White recommended setting 3,000 steps as a first goal.
Nearly 27 million Americans aged 25 and older have been diagnosed with osteoarthritis, the wear-and-tear form of arthritis, according to the U.S. National Institutes of Health. The resulting joint pain and stiffness limits movement for 80 percent of arthritis patients, according to background information with the report.
The study of nearly 1,800 adults found that 6,000 steps was the threshold that predicted who would go on to develop disabilities or not. "If you wear a pedometer and get up to 6,000 steps, you're in good shape," White said.
Other guidelines recommend walking considerably more than this for good health, but White said he was looking for the fewest steps that would help these patients remain mobile.
The study, published June 12 in Arthritis Care & Research, tracked the number of steps taken over a week by adults who were at risk for knee arthritis or already had it. All used pedometers and were part of a large osteoarthritis study.
Two years later the researchers assessed any arthritis-related functional limitations. They found that for every 1,000 steps taken, functional limitations were reduced 16 percent to 18 percent.
Walking not only builds muscle strength and flexibility, it also helps reduce arthritic pain, White and other experts say.
"This study just adds to the vast amount of research and common sense that tells us we need to get off our fannies and out the door," said Samantha Heller, an exercise physiologist at NYU Langone Medical Center in New York City.
Walking "is free and you already know how to do it," she added. "With a good pair of athletic shoes and appropriate attire, you can walk just about any time of year."
Heller said she has patients who say they can't walk because their knees, hips or other joints hurt. "What I explain to them is the less one moves, the weaker the muscles get, and the less stable the joints are, increasing inflammation and pain," she said.
"Sitting around also increases the risk of weight gain, which can adversely affect joints," Heller added.
Pedometers and cellphone apps that measure steps are widely available today, White and Heller noted.
"Pick up a pedometer or get an app to help you see just how many steps you take each day," Heller suggested.
Dr. Natalie Azar, a clinical assistant professor in the departments of medicine and rheumatology at NYU Langone Medical Center, suggested that the new study findings might help encourage people to become more active.
"Overall, this is excellent data on the benefits of moderate exercise and active living on quality of life for people with or at risk for arthritis," Azar said. "It's another piece of literature I will use to convince my patients to move."
For more about arthritis, visit the U.S. National Library of Medicine.