Current issues of ACP Journal Club are published in Annals of Internal Medicine


Therapeutics

Supervised fitness walking for osteoarthritis of the knee improved functional status and reduced pain

ACP J Club. 1992 July-Aug;117:19. doi:10.7326/ACPJC-1992-117-1-019


Source Citation

Kovar PA, Allegrante JP, MacKenzie R, et al. Supervised fitness walking in patients with osteoarthritis of the knee. A randomized, controlled trial. Ann Intern Med. 1992 Apr 1;116:529-34.


Abstract

Objective

To determine the effectiveness of a program of supervised fitness walking and patient education on functional status, pain, and use of medication in patients with osteoarthritis of the knee.

Design

An 8-week randomized controlled trial.

Setting

Inpatient and outpatient services of an orthopedic unit in a U.S. university medical center.

Patients

102 patients > 40 years old (mean age, 69 y) using over-the-counter nonsteroidal anti-inflammatory drugs ≥ 2 days per week and not participating in regular exercise, with a diagnosis of chronic, stable primary osteoarthritis of 1 or both knee joints in association with a ≥ 4-month history of symptomatic knee pain occurring during weight-bearing activities. Exclusion criteria were medical conditions for which exercise would be contraindicated; asymptomatic primary osteoarthritis; dementia or inability to give informed consent; nonambulation; or involvement in another treatment program. 92 patients (90%) completed the study.

Intervention

Entrants were assigned to an 8-week program of supervised fitness walking, stretching and strengthening exercises, and patient education (n = 52) or to routine care (n = 50).

Main outcome measures

A 6-minute test of walking distance and scores on the physical activity, arthritis impact, pain, and medication subscales of the Arthritis Impact Measurement Scale (AIMS).

Main results

The walking distance in the experimental group increased an average of 70 meters from baseline, representing an 18.4% increase (95% CI 9.8% to 27.0%). Patients in the control group showed an average 17-meter decrease from baseline (P < 0.001). On the AIMS physical activity subscale, the control group showed no change from baseline, whereas the intervention group showed an improvement of 39% (CI 15.6% to 60.4%). The walking group experienced a decrease in arthritic pain of 27% (CI 9.6% to 41.4%). Medication was used less frequently in the walking group than in the control group, but the difference was not statistically significant (P = 0.08). The groups showed a similar improvement on the AIMS arthritis impact subscale (P = 0.09).

Conclusion

A program of supervised fitness walking, stretching and muscle strengthening exercises, and patient education improved functional status and lessened arthritic pain in patients with osteoarthritis of the knee.

Sources of funding: In part, Arthritis Foundation and the National Institute for Arthritis and Musculoskeletal and Skin Diseases.

Address for article reprints: Dr. J.P. Allegrante, Cornell Arthritis and Musculoskeletal Diseases Center, The Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021, USA.


Commentary

Joints are protected from weight-bearing load by muscles that serve as shock absorbers, deflecting load from the joints. When muscles are not sufficiently strong or well conditioned, the weight-bearing load is excessively transmitted to the joints. Patients with knee and hip osteoarthritis are often deconditioned from a sedentary lifestyle or from the inhibition of muscle contractions by the pain of arthritis. Treatment has often included avoidance of weight-bearing activities that might exacerbate symptoms. Nonetheless, avoidance of such activities leads to further muscle weakness.

Kovar and colleagues found that a complex intervention including patient education, muscle stretching and strengthening, group discussions about barriers and benefits of walking, and walking up to 30 minutes 3 times weekly improved lower-extremity physical function and decreased pain in patients with knee osteoarthritis. Patients may have improved because of any of the elements of the intervention in this trial, but attention to the patients' problems and muscle-strengthening exercises, with or without walking, are the most likely reasons for improvement. The control group unfortunately received neither extra attention to their problems nor education.

It would probably be a mistake for physicians to suggest that their patients with knee osteoarthritis simply go out and walk more frequently. Most patients, however, would benefit from muscle-strengthening exercises, perhaps reinforced by a physical therapist, and they should also be informed of the importance of muscle strength and fitness in protecting their joints. Graded walking routines on level ground could possibly be incorporated into an appropriate rehabilitation program for patients with osteoarthritis. Whether an 8-week intervention such as this can effect long-term compliance with exercise and long-term benefit to patients remains to be seen.

David Felson, MD
Boston University School of MedicineBoston, Massachusetts, USA