Managing Arthritis

Research on women with knee osteoarthritis

Research on women with knee osteoarthritis

This article is the second in our special series on Women and Arthritis.  To read the first article in the series, visit Women and Arthritis.

Q&A with Dr Monica Maly: Women, knee OA and mobility

New research shows that mindset can be a powerful tool for women when it comes to maintaining mobility with knee osteoarthritis (OA). For people with OA, mobility can be affected by a mix of elements, including pain severity and frequency, muscle strength, and confidence in being able to perform physical tasks. This confidence is called “self-efficacy,” and it was one of the factors that was examined in a recent two-year study of 38 women.

The study, co-authored by Anthony Gatti and Nick Brisson of McMaster University and supervised by Dr Monica Maly, associate professor in the department of kinesiology at the University of Waterloo, focused on women because they are more prone to knee OA, and it often has a bigger impact on their mobility. The study findings: women with more pain and less confidence in their abilities had worse mobility two years later, regardless of their knee muscle strength. What does this mean for women with knee OA? Strategies to maintain mobility should focus on pain control and increasing confidence, which in turn can boost mobility. In other words, empowerment can be a key tool to help women with knee OA successfully manage their disease. The Arthritis Society spoke with Dr. Maly to get a deeper look at the study.

Arthritis Society (AS): How do you explain “self-efficacy” to people?

Dr. Monica Maly (MM): I usually describe it as how certain we are that we can complete a particular task. Self-efficacy is specific to a task, so we could have a really high self-efficacy about driving our car for example, but we might have a different level of self-efficacy for running a marathon. The theory underlying self-efficacy is that our beliefs are a really important driver for our performance. If I believe I can run a marathon, my chances of doing that are much greater than if it I try to engage in running a marathon but in my heart I really don’t think I can do it.

AS: Why were you interested in self-efficacy as it applies to arthritis?

MM: There are several studies that have shown cross-sectionally that self-efficacy is associated with mobility outcomes with people with arthritis. We know that people who believe that they can achieve a mobility task do better than those who don’t feel so certain. We were very interested in whether or not self-efficacy at baseline [the beginning of the study] could predict how someone progresses through the disease over time. We were also curious about whether pain at baseline predicts how people do in the future. And we were also were interested in muscle strength. Muscle strength is another variable where we’re not terribly certain about its role. We know that people who are weaker have greater risk for osteoarthritis, but we didn’t know if it would be a risk for worsening. We were really interested in those three variables: self-efficacy, pain and strength.

AS: You asked people to list their level of certainty in response to a number of different statements. What kinds of things were on the list?

MM: The statements in the questionnaire cover some mobility tasks, such as, “I feel certain that I can complete a walk over six minutes. I feel certain that I can climb a set of stairs. I feel certain that I can prepare a meal.” They also cover some tasks around managing pain: “I feel fairly certain that I can control my pain. I feel fairly certain that if I do become painful I can do something to make my pain better.” 

AS: Your study also looked at how knee strength affects OA. What were some of the findings?

MM: I think this piece is really intriguing. What we know is that people who are weaker tend to have greater risk for OA. The mechanisms by which that happens remain unclear. We do think that the knee benefits from having some muscular support; that the muscles around the knee have the capacity for distributing where the load takes place inside the knee. If you have weak muscles, you’re not going to be able to redistribute those loads so much. We also think that those muscles can be shock absorbers so they can absorb some of the load. So if you have weaker muscles, the ability to take the load away from the other joint structures like the bone and the cartilage may be poorer. We don’t fully understand the mechanisms, but we know the relationship is there.

AS: In your discussion about some of the possible implications of the study findings, your study says that treatments to improve mobility may also want to include getting people to “consciously acknowledge their muscle capacity.” Can you explain this a bit further?

MM: I’m going to briefly return to my marathon analogy. The best way I can be certain that I can complete a marathon is to do it. And so we want to give people the opportunity to witness themselves doing something that requires lots of knee strength and draw their attention to it. In a rehabilitation type of environment, we ask people to do specific movements, like squats, exercises on machines and lunges, but it may be helpful to coach them through it and point out to them: “this is an exercise you weren’t able to do six months ago, but here you are doing it now.” To draw their attention to the fact that they are actually doing better, to draw their attention to what it feels like to contract those muscles. This could be of benefit around pain: “Six months ago, climbing the stairs was creating pain that was 6 of out 10 and today you’re telling me it’s 2 out of 10.” Just drawing their attention to the change that has happened. Sometimes we don’t acknowledge that.

AS: In that scenario, it’s the physiotherapist or another professional who is doing the coaching. Is it helpful for a person living with arthritis to track their own progress and boost self-efficacy that way?

MM: I think that the patient themselves could absolutely do that. [However,] one of the sources of self-efficacy is getting some support from outside yourself. It’s part of the mechanism of group exercise—having the support of peers and the support of someone that you identify with as an instructor can help boost self-efficacy. If you have your peers saying “look at what you can achieve,” that actually helps boost your certainty that you can do it.

To learn more about getting and staying active, visit the Arthritis Society’s online module Staying Active.

This research was supported in part by a Graduate PhD Salary Award from the Arthritis Society.

Reference: Brisson NM, Gatti AA, Stratford PW, Maly MR. Self-efficacy, pain, and quadriceps capacity at baseline predict changes in mobility performance over 2 years in women with knee osteoarthritis. Clin Rheumatol. 2018 ;37(2):495-504.