By Dr Cathy Chapple, School of Physiotherapy, University of Otago

Co-investigators: Dr Prasath Jayakaran, School of Physiotherapy, University of Otago and Dr Rebecca Grainger, Wellington School of Medicine, University of Otago

We know that exercise is beneficial for managing the symptoms of knee osteoarthritis. One of the significant challenges is getting people to do the right amount of exercise to make a difference. So we were interested to see if making exercise more fun, by using video games (exergaming), would help to engage people in exercise. Exergaming using the Wii Fit™ gaming platform also had to produce measurable benefits such as increased muscle strength and decreased instability of the knee. The first step was to conduct some small scale research to test the feasibility of the study and to get some preliminary idea of effectiveness.

We found that an exercise programme using the Wii Fit™ supervised once per week by a physiotherapist in a clinic setting, and repeated twice more per week at home, can result in increased strength of the muscles around the knee for people with osteoarthritis.

To get the best gains, you need to exercise for 12 weeks at least three times per week. Higher levels of enjoyment and overall benefit were seen in those people who completed 12 weeks of exercise using the Wii Fit™. Some early results suggest the increase in muscle strength may decrease the impact of knee instability on everyday activities, and lessen the number of falls; however, a more extensive study is required to investigate this further.

The results are broken down to muscle strength, knee instability, and overall change in the affected knee/s as evaluated by the participant:

Muscle strength

There was a 37,5% difference in quadriceps muscle strength at 13 weeks for the group exercising with Wii Fit™ compared to the control group. Furthermore, looking at the 12 participants who completed 12 weeks of intervention with the Wii Fit™, there were significant increases in both quadriceps and hamstrings muscle strength.

Knee instability

At baseline 17 of the total 23 participants in the study reported knee instability that interfered to some extent with everyday activities, four of these participants experienced daily episodes of instability. At the 13-week follow up 13 of the 17 participants still reported instability affecting their activity, but none reported daily episodes of instability.

Looking at the 12 participants who completed the programme, 8 out of them reported improvement in instability, four of them were the same, while none had worse instability. In the control group, about half the participants reported improved instability, while the other half were the same or worse.

Falling is common in people with knee osteoarthritis, and knee instability may contribute to this. At baseline, four participants reported falls in the previous three month period (two in each group). At 13 weeks no falls were reported for the previous three months in the Wii Fit™ group, while the same two control group participants reported one further fall each. Both these participants went on to complete the Wii Fit™ intervention after the initial analysis. After 12 weeks of exercising on the Wii Fit™, one of them reported a fall, and one had no falls during those three months.

Overall patient rating of change in their affected knee (GROC)

Retention of participants in the study clearly showed us that exercising with Wii Fit™ is not for everyone. Early on in the intervention phase, people withdrew for a variety of reasons, meaning we had to modify our study design and analysis.

Of the total 12 participants who completed 12-weeks of Wii Fit™ exercise, 10 completed the GROC. Of these, nine of them reported meaningful change in the overall condition of their knee, only one out of ten reported very much worse, and two did not respond to this question.

In the control group, only one out of nine who completed the GROC reported meaningful improved change, and all other respondents reported moderate, little or no change in the overall condition of the knee at the 13-week follow-up.

These findings suggest that if participants were able to stick with the 12-week programme of Wii Fit™, their knees were stronger, more stable, and they felt better overall. Most people who completed the programme reported they enjoyed using the Wii Fit™ and found it was more fun than usual exercises. They also appreciated having an appointment once per week with the physiotherapist who could correct and encourage them with their exercises. The physiotherapist could also progress the programme by adding new games to keep things interesting and provide added motivation.