Volume 12, Number 2, 2003
Participants in a research study being conducted by two UD faculty members may find that just showing up for the first session is a step in the right direction.
Todd Royer, assistant professor of health, nutrition and exercise sciences in the College of Health and Nursing Sciences, and Irene Davis, associate professor of physical therapy in the College of Arts and Science, are evaluating the effectiveness of orthotic devices--in-shoe inserts--in treating the pain resulting from knee osteoarthritis. About 100 research subjects, ages 40-75, are taking part in the study.
A degenerative joint disease affecting mostly middle-aged and older people, osteoarthritis is characterized by the breakdown of cartilage in the hands, knees, hips, back and feet. Cartilage is the part of the joint that cushions the ends of bones, and its breakdown results in bones rubbing against each other, causing pain and loss of mobility.
According to the Arthritis Foundation, X-rays confirm that most people older than 60 show signs of the disease, with about one-third having actual symptoms. It affects an estimated 20.7 million Americans, mostly beginning after age 45, and is more common in women.
Royer and Davis' study, "Effect of In-shoe Orthoses on Lower-Extremity Function in Patients with Knee Osteoarthritis," is part of a $6.4 million grant from the National Institutes of Health to UD's Center for Biomedical Engineering Research to study arthritis.
Awarded through UD's Center of Biomedical Research Excellence (COBRE), the five-year grant is co-directed by Thomas S. Buchanan, associate professor of mechanical engineering, and Stuart Binder-Macleod, professor and department chairperson of physical therapy. In addition to Royer and Davis' work, the COBRE grant is funding other projects involving knee osteoarthritis.
The cross-discipline approach between biomedical and movement sciences under the COBRE program matches junior faculty such as Royer with veteran faculty such as Davis, who has more than 20 years of experience in physical therapy and is director of the UD Running Injury Clinic. Stephanie Crenshaw and Robert Butler, graduate students in biomechanics and movement science, are assisting with the research.
Royer says his and Davis' project focuses on mobile individuals, since in-shoe orthotic devices can benefit only those who are ambulatory. During the first of three 90-minute sessions, participants in the study are asked to complete a six-minute walk and to go up and down stairs. They are fitted with a new pair of walking shoes and an in-shoe orthotic device.
"Participants take the tests both with and without orthotics," Royer says. "We ask them to rate their knee pain before and after each testing procedure."
Roughly two weeks after the first test, participants return to the lab for a motion analysis test and a repeat of the functional assessment test. Activities during the second testing session include repeatedly walking along a 25-meter walkway at a comfortable pace. Reflective markers are affixed to the subjects' legs and inserted through openings cut into the rear of the walking shoes supplied by the lab. The sensors allow the subjects' movements to be recorded by video cameras in the lab.
"Patients typically report a decrease in knee pain with orthotic use," Davis says, "but previous studies in the literature do not explain why pain is reduced."
To try to answer this question, Royer and Davis use gait analysis to test the torque (force) and motion of the knee, which gives researchers an indication about the loading of the knee joint.
"A reduction in pain may suggest that we are changing forces at the knee joint," Davis says. "In the future, we also plan to measure bone mineral density at the knee joint before and after 12 months of orthotic use. Changes in bone density may indicate altered loading patterns in the knee."
Over a one-year period, participants wear the supplied walking shoes with the inserts. Researchers periodically phone them to check on their use of the insert, how comfortable it is and whether their use of pain medication has changed. At the end of the year, participants return to the lab for a repeat of the tests performed during the second session.
"It is still early, and the study is still going on," Royer says, "but we have seen changes in walking patterns and a reduction in pain levels."
One of the goals of their research, Royer and Davis say, is to enable their subjects to postpone or prevent the need for knee surgery.
"This is a conservative approach," Davis says. "The other end of the treatment spectrum would be surgery. If the orthoses reduce pain, then surgery can be delayed, which is beneficial because knee replacements do not last forever."
Royer agrees, adding, "It's nice to conduct research that has the potential of benefiting folks who are seeking pain relief."
He also praises the multidisciplinary approach to research. "I have some experience in osteoarthritis research, and Irene has the expertise in orthotic treatment," he says. "Our collaboration on this project has been a great experience for us and our graduate students."
Royer, CHNS '93M, has a doctoral degree in exercise science and biomechanics from Arizona State University. He joined the UD faculty in 2000.
--Jerry Rhodes, AS '03