Osteoarthritis (OA) commonly affects a variety of people regardless of gender, age, occupation or body type. Our panelists consider the role of exercise in managing OA, discuss potential obstacles and offer strategies for improving patient compliance to exercise.

Q: In regard to patients with OA, what factors affect adherence to exercise regimens? What strategies can clinicians use to enhance compliance with exercises in this patient population?

A: Elizabeth Schlenk, PhD, RN, says strength training and aerobic exercise are important components of treatment for OA of the hip and knee. She notes studies have found that both forms of exercise have positive effects on pain, self-reported disability and walking performance.^1-5 Unfortunately, Dr. Schlenk says only 50 to 70 percent of people with OA in clinical trials engage in these types of exercise regimens.^6,7

“Pain and functional limitations hinder the adoption and maintenance of exercise programs in people with OA of the hip and knee,” explains Dr. Schlenk. Dr. Schlenk adds that other factors such as “self-efficacy,” outcome expectations and perceptions about the benefits of exercise can have an impact on a patient’s adherence to exercise regimens. External factors that can influence exercise adherence in these individuals include social support, a lack of time and perceived barriers to exercise.⁸

However, there are strategies one may employ to improve exercise adherence. Dr. Schlenk recommends the following approaches:
• self-monitoring using a paper or electronic diary;
• monitoring and follow-up by a health professional;
• frequent short sessions of moderate intensity exercise;
• social support from family and friends; and
• self-efficacy based interventions.^8,9

Dr. Schlenk says this self-efficacy is the belief that a patient can perform a given behavior under different conditions.10 In her practice, Dr. Schlenk notes they have developed and tested self-efficacy-based intervention for older adults with OA of the knee. She says this system consists of four elements:
• mastery (which consists of graduated quadriceps strengthening exercise and walking goals);
• modeling (patients use an exercise videotape);
• social persuasion (patients use available telephone counseling); and
• physiological feedback (interpretation of exercise-related sensations).

Dr. Schlenk and her associates found that the intervention group had significantly greater quadriceps strengthening exercise adherence at a six-month follow-up in comparison to the control group. They also found significant increases in the minutes per week spent walking and noted a greater proportion of intervention patients (61.5 percent versus 40 percent) who reported at least 150 minutes of physical activity at the six-month follow-up.

Q: Traditionally, physical therapists have instructed patients with knee OA in aerobic exercises like bicycling, walking, swimming and strength training. Others have discussed the addition of devices like wobble boards. What are your findings to support these additions?

A: Although aerobic exercise and strengthening exercises are reportedly helpful for reducing pain and improving function in patients with knee OA, the overall effects reported thus far in various studies have been small to modest at best, according to G. Kelly Fitzgerald, PhD, PT, OCS.

He says there is room for improvement.

“We have reported recently that a number of people with knee OA complain of joint instability and that this instability can affect functional performance,” says Dr. Fitzgerald.¹¹ “Aerobic and strengthening exercises alone may not be enough to overcome deficits for these people.”

Assessing The Role Of Medications For Knee OA

Accordingly, Dr. Fitzgerald and his colleagues hypothesized that training techniques they have previously found useful in younger individuals with unstable knees may be modified to facilitate benefits for people with knee OA who have a similar problem. Using this hypothesis, Dr. Fitzgerald and his associates designed a modified treatment program using a combination of agility and balance exercises with tilt boards and roller boards.¹² He adds they are currently conducting a randomized trial, funded by the National Institute of Arthritis and Musculoskeletal and Skin Disease, in order to determine whether adding these exercises to aerobic and strength training programs will increase the overall effect of improved pain and function in people with knee OA.

Dr. Fitzgerald notes some research has suggested that adding functional training activities to exercise programs can also lead to improved strength and function among elderly patients. He says these types of training activities would include stair climbing, sit to stand transfers, car transfers, carrying objects, etc.

Q: Are different exercises beneficial for medial compartment disease versus lateral compartment disease?

A: “To my knowledge, there have been no studies that have clearly shown that certain exercises are more beneficial than others depending on compartmental disease,” maintains Dr. Fitzgerald.

However, Dr. Fitzgerald says some studies have shown that anything that might increase varus loading (i.e. a hip abduction straight leg raise) will increase loading of the medial compartment and anything that increases valgus loading (i.e. a hip adduction straight leg raise) can increase loading of the medial department. Likewise, Dr. Fitzgerald notes that people with varus deformity (bow legs) may put more stress on the medial compartment and those with valgus deformity (knock knees) may put more stress on the lateral compartment during weightbearing activities. Dr. Fitzgerald points out there are special types of braces designed to unload either the medial or lateral compartment. He says these braces could help some of those people who have medial or lateral compartment disease.

Dr. Schlenk is an Assistant Professor at the University of Pittsburgh School of Nursing. Dr. Fitzgerald is an Assistant Professor at the University of Pittsburgh School of Health and Rehabilitation Sciences. Dr. Starz is a rheumatologist in clinical practice at the University of Pittsburgh Medical Center. Ms. Brandenstein is a physical therapist at the Centers for Rehabilitation Services, a division of the University of Pittsburgh Medical Center.