Exercise for Osteoarthritis of the Knee

Can exercise help this patient?

Mr S is a 55-year-old man with a 3-year history of progressively increasing bilateral knee pain, left worse than right. During the past 3 months, he was in a sedentary job, his weight increased by more than 10 kg, and his symptoms increased significantly. Mr S reported left knee pain as being 6 out of 10 on the visual analog scale (Tab. 2), and he was using a walking stick to walk any distance. He had minimal symptoms at night, stiffness that resolved after about 15 minutes in the morning, and symptoms that worsened as the day went on. His pain was exacerbated by walking more than 15 minutes or on hills and by long periods of sitting. Mr S found relief by using a walking stick, moving his knees when sitting, and taking regular doses of a nonsteroidal anti-inflammatory drug and paracetamol. Mr S's radiographic films showed a decreased medial knee joint height with osteophyte formation. Overall, his presentation was consistent with moderate knee OA.

Mr S was working full time, sitting at a desk for most of the day, and reported that he was managing his daily activities (eg, shopping, gardening) with slight difficulty. On the Patient-Specific Functional Scale²¹ (/10), where a score of 0 was “unable to perform activity” and 10 was “able to perform activity at the same level as before,” he identified 3 activities that he had difficulties with: walking on a flat surface, walking on hills, and sitting (Tab. 2). Mr S had no limitations in knee range of motion; however, there was pain at end-range flexion on the left. Knee extension was slightly weaker on the left. He also had calf and hamstring muscle tightness that was worse on the left than on the right.

How did the results of the Cochrane systematic review apply to Mr S?

Exercise is recommended as part of the first-line care for OA, and results of the Cochrane review support the use of exercise. Mr S himself stated that he had no regular exercise routine, and his goal was to be shown an appropriate exercise regimen that would help him improve his ability to walk and decrease his pain.

Mr S started on an exercise program that included quadriceps and gluteal muscle strengthening exercises and calf and hamstring muscle stretches. The dose for the strengthening and stretching exercises was established based on examination findings, and the exercises were progressed to more challenging functional exercises with increased resistance as he improved. These exercises included sit-to-stand exercises, step exercises with emphasis on good lower-limb alignment, and resisted gluteus medius muscle exercises in a standing position with a blue Thera-Band.* After 4 weeks, he was able to commence a progressively paced walking program, starting with 20 minutes on alternate days. If there was no increase in his symptoms, Mr S was instructed to increase the walk by 5 minutes at a time until he was comfortably managing 45 minutes. He also had borrowed a stationary bicycle and was encouraged to use it for up to 20 minutes 3 times a week. In conjunction, at his first treatment, Mr S was given education on OA and the importance of self-management strategies (exercise, pacing, and weight loss).

How well do the outcomes of the intervention provided to Mr S match those suggested in the systematic review?

After 8 weeks of strengthening, stretching, and progressive walking and bicycle exercises, Mr S reported a decrease in his pain. His physical function improved. The decrease in pain on the visual analog scale and improvement in physical function on the Patient-Specific Functional Scale were greater than the minimal clinically important difference for each scale^21,22 (Tab. 2). Mr S reported that he was now able to walk for almost an hour before needing to rest and rarely needed to use his walking stick.

Can you apply the results of the Cochrane systematic review to your own patients?

The findings of the Cochrane review apply well to Mr S. He had specific deficits that could be addressed with exercise, he was keen for an exercise program to improve his deteriorating condition, and he subsequently benefited from the program. As a person who is middle aged and has moderate symptoms compounded by lifestyle factors (eg, sedentary lifestyle, increasing weight), Mr S is not atypical of the patients with OA seen by physical therapists. Therefore, benefits from exercise can be expected from most patients who follow an exercise program. The Cochrane review shows that variations in the delivery, content, and dosage do not influence outcomes, except that a higher number of contact sessions leads to greater effects, meaning that physical therapists can adapt the exercises to the individual patient (eg, home vs gym-based programs, strengthening exercises vs aerobic exercises vs tai chi).

What can be advised based on the results of this systematic review?

Patients with knee OA often experience pain and problems in activities involving the lower limb (eg, walking) or prolonged positioning (eg, sitting), as well as stiffness after a night's sleep. Exercise can target these specific deficits. Knee OA also is a potentially deteriorating condition without a curative treatment. Therefore, patients with knee OA are likely to benefit from exercise in managing this long-term condition. It is the physical therapist's role to prescribe appropriate exercises to suit a patient's goals, lifestyle, and overall health condition and ensure that the exercise program is progressive and challenging in order to deliver benefits.

The benefits of exercise are contingent on a patient's adherence to the exercise program. Evidence to date shows that, although exercise has short-term benefits in reducing pain and improving physical function, these benefits may not persist in the long term without adherence to the exercise program. Therefore, strategies to increase long-term adherence to exercise, such as adding in booster sessions, may be necessary to maximize the benefits of exercise for people with knee OA.