Exercise as it relates to Disease/Effects of different types of exercise on people suffering from knee osteoarthritis

What is the background to this research?
Knee Osteoarthritis is one of the most common forms of joint disabilities, and is becoming more prominant as the population ages. This is due to age, and aging, being a leading risk factor to suffering from this painful disability. Osteoarthritis can be defined as the progressive breakdown of articular cartilage, which results in the space of joints minimizing. As well as this, other issues can arise in the joint as a result, such as ligament abnormalities, which can worsen symptoms of pain.

Due to knee osteoarthritis being such a big issue in the aging population, and it being such a painful and debilitating disability, intervention and management is vital. Successful intervention of a disability such as this derives off:
 * reducing the amount of pain experienced
 * improving function
 * increase strength
 * increase range of motion
 * improve walking gait
 * improving quality of life

One theory is that exercise can serve as an adequate means of management, and the research completed by Ryo Tanaka et al. (2013) focuses on which type of exercise is more beneficial and whether it is an appropriate means of management for controlling knee osteoarthritis, and more specifically the pain associated with it.

Where is the research from?
This research was conducted from the Department of Integrated Rehabilitation, Hiroshima International University, Japan.

What kind of research was this?
The research involved was a systematic review and meta analysis of randomized controlled trials over an 8 week period, exercising 3 times per week.

What did the research involve?
The systematic review and meta analysis involved people who had been diagnosed with knee osteoarthritis, who were not in a preoperative or postoperative state. Along with this, no gender, age or body mass index was taken into consideration. The trials compared the effects on exercise as an intervention on control groups, who did not exercise, or took part in a psycho-educational intervention. The trials were set up over an 8 week period, where you had to take part in therapeutic exercise for a minimum of 3 times per week. The exercise groups were divided into 3 subgroups: non-weight-bearing strength training, weight-bearing strength training and aerobic exercise. The measure of these trials were perceived pain in the affected knee.

What were the basic results?
The findings in the results were the standardised mean difference of each subgroups when compared to the controls after 8 weeks of intervention. the findings were:


 * non-weight-bearing strengthening exercise: -1.42
 * weight-bearing strengthening exercise: -0.70
 * aerobic exercise: -0.45

How did the researchers interpret the results?
The results showed that it does not necessarily matter what form of exercise a person with knee osteoarthritis participates in, as they all show a significant positive effect on relative pain. Although the results did show that for the greatest results, non-weight-bearing strengthening activities were deemed to be most effective, when compared to weight-bearing strengthening activities and aerobic exercise.

What conclusions should be taken away from this research?
The main conclusion to be taken away from this study is that any types of exercise is beneficial to relative pain and as a basic means of intervention. This was evident throughout all of the studies that were included in the meta analysis,        and the systematic review conducted by Tanaka et al. For the best outcome, non-weight-bearing strengthening exercise should be undertaken as this had the most substantial improvements throughout the subgroups, especially in the short term.

What are the implications of this research?
This research was the first of its kind to show a relationship between different types of exercise (in particular subgrouping weight-bearing and non-weight-bearing strengthening exercise) and its relative contribution to minimising pain associated with the knee osteoarthritis. Most of the findings however were limited to short term interventions, and it is unclear whether this type of intervention is suitable for a long term treatment for knee osteoarthritis and the pain associated with it. This research also suggested that non-weight-bearing strengthening exercise was the most beneficial to decreasing relative perceived pain. This may cause an issue in the long term as prolonged non-weight-bearing strengthening exercise can cause a decrease in bone mineral density, and also can cause thinning of the cartilage of joints, as mechanical stimulus is needed to maintain cartilage and this can cause increased pain as a result. The decreased bone mineral density can cause issues in elderly patients with knee osteoarthritis as a decreased bone density is associated with increased falls and fractures. Therefore more study is needed in the area of the combination of non-weight-bearing strengthening exercise and weight-bearing strengthening exercise as a means of intervention.

Additional readings
Basic exercises for knee osteoarthritis

About knee osteoarthritis

Osteoarthritis prevention

Other methods of pain management