Evidence Summary

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Exercise programs focused on 1 type of exercise and with 3 sessions/week reduce pain and disability in knee osteoarthritis

Juhl C, Christensen R, Roos EM, et al. Impact of exercise type and dose on pain and disability in knee osteoarthritis: a systematic review and meta-regression analysis of randomized controlled trials. Arthritis Rheumatol. 2014;66:622-36.

Review question

What are the important features of exercise programs for reducing pain and disability in knee osteoarthritis?


Osteoarthritis is the most common form of arthritis. It results from the wearing down of the cartilage that cushions the ends of the bones in joints such as the knee, hip, and spine. People with osteoarthritis can have pain, tenderness, joint stiffness, and reduced flexibility. These symptoms are often managed with medications (e.g., pain relievers and anti-inflammatory drugs) and exercise.

How the review was done

The researchers did a systematic review, searching for studies that were published up to May 2012.

They found 48 randomized controlled trials of 59 exercise interventions. More than 4,000 people with knee osteoarthritis were included. They ranged in age from 52 to 74 years (average age 64 years), and about 75% were women. The average pain score was 46 out of 100 (with 100 being the worst possible pain).

Different types of exercise were compared with a non-exercise control group. Aerobic exercise, such as walking and swimming, strengthens your heart and lungs. Resistance exercise (or strength training) involves the use of, for example, weights, exercise machines, or exercise bands. The third type of exercise, performance exercise, was not defined by the authors.

What the researchers found

All exercise

Compared with a non-exercise intervention, exercise reduced both pain and disability by a moderate amount.

Types of exercise programs

Aerobic, resistance, and performance exercise each reduced pain by a similar (moderate) amount.

The effect of aerobic exercise on pain increased as the number of supervised sessions increased (that is, every additional 10 supervised sessions).

Resistance exercises that focused on quadriceps (thigh muscle) strength reduced pain and disability more than resistance exercises focused on general lower-leg strength.

Single type of exercise vs a combination of different exercise types

Programs that focused on 1 type of exercise reduced pain and disability more than programs that used a combination of aerobic, resistance, and performance exercises.

Programs focusing on 1 type of exercise and including 3 or more sessions/week reduced pain and disability more than those that included less than 3 sessions/week.


In people with knee osteoarthritis, exercise reduces pain and disability by a moderate amount. Programs that focus on one type of exercise reduce pain and disability more than those using a combination of exercise types. Programs focusing on one type of exercise and including 3 or more sessions/week reduce pain more than programs with less than 3 sessions/week.

Exercise vs non-exercise interventions for knee osteoarthritis

Type of exercise

Effect on pain

Effect on disability


Moderate reduction, equal to about an 8.5-point improvement out of 100

Moderate reduction, equal to about an 8.3-point improvement out of 100


Moderate reduction

Moderate reduction


Moderate reduction

Moderate reduction


Small reduction

Moderate reduction

Single exercise type

Moderate reduction

Moderate reduction

Combination of resistance, aerobic, and performance exercise

No effect

Small reduction



Control group
A group that receives either no treatment or a standard treatment.
Randomized controlled trials
Studies where people are assigned to one of the treatments purely by chance.
Systematic review
A comprehensive evaluation of the available research evidence on a particular topic.

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