Updated: Apr 13, 2020
One of the most common places people get osteoarthritis (OA) is in the knee. If you have knee OA, you likely understand that the most commonly reported symptom is pain, however swelling, tissue stiffness, instability and muscle weakness also contribute to the severity of the condition.
Arthritis is a term we hear nearly daily, this is not surprising as 9% of Australians are currently living with the condition. But what is it? When people say arthritis, they are usually talking about OA, which is a chronic joint disease that affects the whole joint including cartilage, bone, ligament and muscle.
Unfortunately, there is no cure for knee OA. However, it is not all doom and gloom! Research demonstrates time and time again that exercise is great for slowing the progression and improving common insufficiencies that are associated with OA such as strength, joint range of motion, proprioception (awareness of the body in space), balance and cardiovascular fitness.
Besides those listed above, one of the key benefits of exercising with OA is the role this plays in pain modulation. Although we are only just beginning to scratch the surface of understanding pain as it is such a complex topic, here is what we do know. Pain is a response mechanism, it reacts to a stimulus within the body, as such it does not always mean there is actual damage or danger. It is common over time for the way we perceive pain relating to knee OA to not correctly represent what is happening in the knee.
Exercise-induced hypoalgesia is the fancy sounding term used to describe the benefits of exercise for those with knee OA. What this means is that exercise has an effect whereby it reduces the strength of the signal to the brain that represents pain. By gradually introducing exercise into your daily routine, you are allowing the body to relearn that movement doesn’t mean it is causing damage and thus reducing the pain response mechanism.
Similarly, exercise plays a large role in creating an anti-inflammatory response. To exercise involves putting stress on the body, this stimulates a response in the form of upregulating some hormones, proteins and enzymes, while also downregulating others. While this is great news, the real benefits come from regular activity. If you imagine doing an exercise session every Monday, you would likely feel the benefits for a few days, however, by the end of the week, you are likely to feel stiff again. By regularly exercising, you can reap the benefits of both hormonal responses, pain modulation, in addition to more commonly discussed benefits such as strength, flexibility, balance.
What types and how often?
For best result exercise should be individualised to the patient, accounting for their history, age, strength, mobility, comorbidities and interests. As a guide, you should be aiming to achieve 150 minutes per week of moderate intensity activity, such as brisk walking. You may be thinking, but I have never exercised and I have sore knees, how am I going to achieve this. The suggestion for those with OA is to be as active as their condition permits. So, when beginning a new exercise regime you may start with a walk to the end of the street and back once per day. As your tolerance builds you will be able to perform this multiple times a day and in time increase the length of the walk.
More specifically to knee OA, flexibility training is beneficial as tissues around the joints become stiffer. This stiffness may be due to the physical changes in the joint and possibly related to moving the joint through less range due to pain. Exercise and Sports Science Australia (ESSA) suggest aiming to stretch 3-5 times per week. Each stretching session should include between 3 and 5 stretches of each muscle group, with a hold of 30 seconds. Stretching should aim to move the joint through a maximum range of motion without provoking pain.
Strength training has many benefits for those with OA. It is understandable that people with knee OA have decreased strength as pain may limit participation in previously completed physical activities. That is why it is imperative to do strength training that is appropriate for your current ability and previous training history. Isometric training is great for those with knee OA as it allows the activation of muscles around the knee, without movement at the knee that may be provocative. ESSA recommend beginning with this style of training, performing 3-10 contractions for 1-6 seconds daily. As tolerated dynamic strength should be incorporated, with the goal of 3 sessions per week of high-intensity training lasting for between 45 and 60 minutes.
Take away tips to get you started!
Start small and build up. Rome wasn’t built in a day, much like your OA didn’t develop overnight. By making small changes and incorporating regular, purposeful movement into your daily routine, you will reap the benefits for years to come.
Find the best time of day. If you find you are stiff in the mornings, this may be a better time to do some light stretching, rather than going for a walk.
Create a routine. Often we find ourselves saying we don’t have time to exercise, at times this can be true, however, it is generally that we haven’t prioritised exercise.
While the guidelines above provide good direction on where to start and what to aim for, they are not specific. I cannot overstate the importance of an individualised program in the successful inclusion of exercise and journey to better health.