Yoga and Knee Pain
Can I do yoga when my knee hurts? This is a question I am frequently asked and often by peope who have knee osteoarthritis. I have therefore delved into some of the evidence together with my professional experience, as a physiotherapist and yoga instructor, to write this article. I will discuss what knee osteoarthritis is and the impact of exercise, with a focus on yoga.
What is Knee Osteoarthritis?
Osteoarthritis is the process that occurs in the bone as a result of cartilage loss. Cartilage is a type of rubbery tissue which surround the end of the bone in a joint. This gives cushioning to the joint. The cartilage can become disrupted due to accidents, rheumatoid disease as well as the general ageing process. When the cartilage becomes damaged the bone will try and repair itself by growing little bony spurs. These spurs can catch surrounding structures and result in an inflammatory response and pain.
Osteoarthritis of knee can result in stiffness, pain and swelling. The process will affect the whole joint, including the muscles. Certain aspects can predict how the osteoarthritis will progress. An example of this is the amount of loading that occurs to the medial aspect (inside) of the knee. When you are standing or walking, you may be placing more stress to the inside of the knee. This can lead to the osteaortitis of this part of the joint worsening.
As a result of the pain and swelling, the muscles of the inside of the knee (vastus medialis, part of your quadriceps) can become disinhibited and therefore become weaker. Frequently this is not isolated just at the knee joint. Often there is a secondary issue with weaker muscles around the outside of your hip - your glutes. If your glutes are weak this will also affect knee alignment and increase loading through the inside aspect of your knee.
Yoga and Knee Osteoarthritis
Overall the evidence for yoga in relation to musculoskeletal health is pointing in a positive direction. However, the research is generally not of the best quality. When looking at research it is important to not just look at the conclusion. We need to consider whether the methodology was of sound quality. As concluded in a systematic review from Kan et al. 2016, better research is required to understand the effect of the benefits of yoga. But based on lower quality studies there appears to be a positive impact of yoga on pain, quality of life and short distance mobility. To have an effect, you need to continue doing yoga for a longer period of time (>12 weeks).
The above research does not suggest that yoga is better than any other exercise. The research for general leg strengthening exercises is largely positive. It also suggests that more than 12 weeks of regular and consistent sessions are required.
Can Yoga be Bad for my Knees?
Yoga is not simply yoga, and with modern practice of yoga there is a plethora of styles and approaches. It is therefore important to find the right one for you. A majority of the research is done on traditional Hatha Yoga. Hatha tends to be a bit slower and you spend longer time in the poses.
I was interested to see if there were any specific poses that are better or worse for the knee joint. I found a study looking at the biomechanics effect of yoga on knee loading. The study found that lunge and squat bases poses (e.g. warrior poses, crescent lunge) generally place less stress on the medial compartment of the knee. In opposition, single leg poses ( e.g. tree pose, warrior 3) tend to place more stress on the medial compartment.
However, this is not gospel and it really depends on your technique. A warrior pose performed with the knee slightly collapsed inwards is also going to increase the medial load. Single leg poses do not necessarily need to be avoided. They have multiple benefits with improving balance and proprioception. However, you may want to hold these poses for a shorter amount of time. It is always good to work with a qualified instructor to ensure you have the right alignment.
To conclude, yoga can have a positive effect on knee health through improving pain, quality of life and mobility. However, all yoga is not equal and you therefore need to find the right approach for you. Yoga is not necessarily more beneficial than therapeutic exercise for knee osteoarthritis, and it is worth bearing that in mind.
Kan, L., Zhang, J., Yang, Y., & Wang, P. (2016). The effects of yoga on pain, mobility, and quality of life in patients with knee osteoarthritis: a systematic review. Evidence-Based Complementary and Alternative Medicine, 2016.
Kuntz, A. B., Chopp-Hurley, J. N., Brenneman, E. C., Karampatos, S., Wiebenga, E. G., Adachi, J. D., ... & Maly, M. R. (2018). Efficacy of a biomechanically-based yoga exercise program in knee osteoarthritis: A randomized controlled trial. PloS one, 13(4), e0195653.
Longpré, H. S., Brenneman, E. C., Johnson, A. L., & Maly, M. R. (2015). Identifying yoga-based knee strengthening exercises using the knee adduction moment. Clinical Biomechanics, 30(8), 820-826.
For more information regarding arthritis this charity's website has excellent resources: https://www.versusarthritis.org/about-arthritis/managing-symptoms/exercise/