In my last post, I wrote about how yoga can be a great way to keep your knees strong, flexible, stable, and healthy over time. But there are some situations in which yoga can negatively affect your knees. If you have a knee problem prior beginning your yoga practice, even a basic class could potentially tweak or aggravate an underlying abnormality. This is why I always ask new students if they have injuries or health issues I should be aware of. If I know about it, I can provide modifications and special ways of working with an old injury. If not, you are taking a bit of a gamble.
Another way yoga can negatively impact your knees is if you throw yourself into a mixed- or intermediate-level practice without learning the basics of good knee alignment in beginner's classes. I highly recommend you start at the beginning, learn the basic building blocks of a beneficial yet safe yoga practice, and advance gradually to more advanced poses that can challenge the knees (Lotus Pose, for example). I realize that it's sometimes difficult to find an eight-week beginners' series, but it is well worth the effort. Most Iyengar studios still offer this option, and you can take what you learn there into most other styles of yoga with confidence that it will keep you safer in the long run.
It's worth mentioning attitude toward your practice here. A competitive, aggressive attitude that's more common in sports or things like strength training can be your downfall in yoga, injury-wise. It will likely push you to go farther and with less sensitivity to your body’s early warning systems than a more curious, non-competitive attitude. If you know that you fall into the Type A camp, try downgrading your “must go further and finish first” tendency to Type B.
Finally, if you do end up aggravating an old knee injury, or getting a new one, slow down, re-assess your approach to your yoga practice, and ultimately use yoga from that point forward as a healing tool for your knees. Get a private session with the most experienced teacher you can find, for input on how to modify your practice to promote healing. If you end up with a hot, swollen, hard-to-bend knee, get off your feet for a few days. Play around with reclining yoga pose variations, keeping your knees straight until the swelling and pain subsides. Supta Padangustasana (Reclining Big Toe Pose) is one of my favorites in this situation, as well as Viparita Karani (Legs Up the Wall Pose).
Once you can bear some weight, try modified standing poses while sitting on a sturdy folding chair. Once those are easy for your legs, add standing poses where both knees are straight—Mountain, Standing Forward Fold, Triangle, and Pyramid. If those feel OK, add Warrior II to test how your knee handles a deeper weight-bearing bend. If that goes well, try high version of Side Angle Pose with your bottom elbow on your bent leg thigh. This will add a bit more pressure to the joint and let you know if it is ready to go deeper.
In seated poses, try beginning with seated Cobbler's Pose, but let the heels be pretty far away from you hips, and slowly, over the course of a few sessions, bring the heels in closer, which will require a deeper fold to the joint. And I often encourage students with active knee pain prop the knee with a blanket or block in poses like Sukasana (Easy Pose). This can help reduce inflammation in the joint.
And don’t forget to follow-up with your yoga teacher to help guide your healing process. If you get stuck or backslide, go to see your GP, as there are times, hopefully rare, where a medical evaluation is a good idea.