As much as I've already written about the knee, it never seems to be enough. I often take a poll in workshops when heading into the knee section and on most occasions one quarter to half the students will raise their hands when asked how many people are experiencing knee pain? This isn't necessarily a yoga problem, but it's showing up there.
This is a requested article, someone asked me to write specifically about lotus and the medial meniscus. When I do my unscientific polling in workshops, approximately 80% of those people complaining about pain in their knee, say that they experience pain on the medial side of their knee. Approximately 10 - 15% complain about pain on the outside of their knee. The remainder usually complains about pain running through the centerline of their knee or around the kneecap. All three areas express stress in the knee in different ways.
Pain on the inside of the knee seems to be the most popular and is almost always associated with the leg being in a half or full lotus position. My statistics are only my own personal and simple observations turned into a working hypothesis. It seems to me that the most common cause of pain on the inside of the knee is compression of the medial meniscus. I say this cautiously because I know that not all pain on the inside of the knee is going to be the medial meniscus. Nor am I saying that because you have pain on the inside of your knee does this mean that you have already torn your meniscus. You may simply be irritating it repeatedly in the same area.
There are of course other structures in this area that can get inflamed or irritated and cause pain on the inside of the knee. Some of these structures are the medial collateral ligament (MCL), various muscles crossing the inside of the knee and even the joint's capsule can get compressed and bothered.
The reason I lean toward the medial meniscus compression is that I have heard so many stories of knees popping with it in the lotus position. Swelling in the back of the knee and sometimes a regular clicking sound often follows the pop. It's also possible that the knee will lock intermittently after the original pop happens. All of these are classic signs and symptoms of a meniscus tear. The best way to confirm if the meniscus has torn is to go to the doctor and have an MRI taken.
What Is The Meniscus Anyway?
There are two separate pieces of cartilage that make up the meniscus in each knee. Each is an additional piece of cartilage that sits between the femur and the tibia. These are of course the two bones that come together to make the knee joint (femorotibial joint). This extra piece of cartilage serves a couple of functions, one is to add cushioning to the joint and the second is to help with the function of the joint and allow the knee to flex, extend and rotate in the ways that it does.
Each side of the meniscus is more or less crescent shaped and sits on top of the tibia, an area referred to as the tibial plateau. One of the meniscus lives on the inside (medial) and the other is on the outside (lateral). Therefore we have what we call a medial and lateral meniscus. You can further divide them front to back, which in anatomical terms is anterior (front) and posterior (back). The area of the meniscus that is most commonly torn is the posterior portion of the medial meniscus. This also seems to be the area most affected and most commonly injured in the lotus scenario we're talking about.
If The Meniscus Tears, Can It Heal?
This is perhaps the most common question. Unfortunately the answer is a little complicated. The answer depends on where and how badly the meniscus is torn.
In general (there are always exceptions) tears that occur to the outer edge of the meniscus can heal on their own. The reason for this is that there is a small blood supply that feeds this outer edge and can help it heal. The inner part of the meniscus normally doesn't heal on it's own (there are always exceptions). It is when the tears are in this area that surgery could be required. It's also possible that a tear is small enough that one can live with it for quite some time. But keep this in mind… Joints are used to functioning with nearly no friction. A tear in the meniscus is an area where there will be an increase in friction, hence why it often causes irritation, swelling and pain. This friction can do a couple of things, one it can lead to the tear growing in size and two it can also damage the cartilage on the femur that has to slide over the torn area.
Why Is The Medial Meniscus Getting Compressed?
There are two movements that when combined would put the most amount of pressure on the medial meniscus. The two movements are flexion of the knee and internal (medial) rotation of the tibia. In lotus both the femur and the tibia have to rotate externally. If the tibia doesn't have enough outward rotation, there still could be enough in the hip to make up for it, or vice versa. If however both the tibia and the femur lack in their ability to do external rotation then what you have is more internal rotation, which by itself can put pressure onto the medial meniscus. When you combine this with the knee being flexed, as it is in lotus you end up with even more pressure on the medial meniscus.
If you have pain on the inside of your knee, the simple test to see if its a rotational issue is to rotate both your upper and lower leg in external rotation while in lotus (be careful not to push your knee toward the floor too strongly). I've covered this aspect extensively in the knee section of YogAnatomy Volume 1. A section is also available at the bottom of the YogAnatomy home page. This section also shows you other options for what you can do if you already have pain on the inside of your knee (you can also pay for and download the entire knee section here).
What If You Have Pain On The Outside Or In The Centerline Of Your Knee Around The Patella?
No, I didn't forget. If you have pain on the outside of your knee, you're in a club of your own. When I meet people who have pain here, I often find (there are exceptions) that rotation internally of both tibia and femur results in a decrease in their pain (the opposite of what to do if pain is on the inside). Upon further questioning, many of these people are or were runners or cyclists. My hypothesis at the moment is that a tight Iliotibial bands (ITB) is the culprit (I'm sure there are exceptions). The ITB seems to be placing some type of rotational force on the knee that is causing pain. I assume it's rotational in nature because when I rotate the femur and tibia internally, the pain is reduced or goes away.
If the pain is through the midline of the knee I tend to focus on the quadriceps group of muscles first. Either they lack flexibility or they lack strength and either of these could be causing trouble in the knee. I realize that this is unspecific but the actual assessment of the person would be necessary to determine which is the case and what should be done.
The reason for checking the quadriceps when the pain is through the centerline of the knee is because this group of muscles literally wraps around the patella to get to its final destination on the tibia. Therefore it is intimately associated with the functioning of the knee particularly in straightening (extending) the knee. Having said that, there are a number of other issues that can show up in and around the patella, including arthritis and build up of scar tissue under the patella itself.
A Final Note On Surgery For Meniscus Tears
I'm definitely not an advocate for unnecessary surgery. Only you can decide what to do with your own body. If you have a torn meniscus and know it and have been avoiding surgery there are a couple of things you should keep in mind. One is that the success rate for removing a small piece of meniscus is very high, around 90% perhaps higher. This means that the surgery doesn't lead to any further deterioration of the area and wouldn't need surgery again. If it's a large tear and they remove a larger piece, this percentage drops. Finally if they do the type of meniscus surgery where they stitch the meniscus back together, the success rate drops to about 65%.
Second, is that there can be secondary effects of leaving a meniscus tear untreated such as an uneven wearing on the cartilage in the joint, particularly on the femur. This could potentially lead to arthritis in the long term.