Have you ever heard Raffi’s rousing rendition of the children’s song “Knees Up Mother Brown”? It goes something like this:
Knees up Mother Brown,
Knees up Mother Brown,
Knees up, knees up, never let the breeze up,
Knees up, Mother Brown.
Hopping on one foot, hopping on one foot,
Hopping, hopping, never stopping,
Hopping on one foot,
Hopping on the other, Hopping on the other…
I can clearly remember not only singing along, but also dancing enthusiastically to it with my one year old son, Schuyler—so enthusiastically that I was holding him in my arms, too. And then my knee went off its track, and suddenly it wasn’t fun any more.
Admittedly, my yoga practice as a new mother was rather patchy, as were my therapeutic knee exercises for old dance injuries. My knees had actually been talking to me during the preceding week, but I was “too busy” to listen. Later the next day when I was just walking around the house and my knee cap fully subluxed (got off track—more on this later), I thought that it had momentarily slipped three inches off to the side—impossible, but that was the feeling—giving me no sense of support. Now I heard my knee talking to me loud and clear, and knew that I had to get serious. I went to my old workplace, The Center for Sports Medicine, to see Dr. James Garrick, my former boss and knee specialist. (See, I really should have known better!) He prescribed a brace for me and reminded me to exercise my vastus medialis and to apply the RICE treatment.
RICE is Nice for Knees
RICE is an acronym for Rest, Ice, Compression and Elevation. The easiest part of this for me to follow was the compression part, having just been given a compression type knee brace with patellar support to wear. I went right to work on doing the exercises. “Rest” means not doing activities that aggravate the knee directly, or indirectly by overtiring it. Although I was not able to avoid carrying my young child from time to time, no one had to tell me to lay off dancing to “Knees Up Mother Brown”! I elevated my knee with a pillow at night in bed and the occasional legs-up-the-wall restorative pose when I could squeeze it in between diapers, feeding, etc. The least appealing part for me, yet one of the most important, was icing my knee, even though the swelling was enough to be visible. I would put my leg up on a chair (partial elevation) at meal times or whenever else I could to ice it for about twenty minutes—with a light towel around it to keep from irritating the skin.
Here is what my former boss, Dr. Garrick, says about knee injuries in his book, Peak Condition :
“Gulp! Instability. That horrible word, resounding with all sorts of undesirable connotations, whether it be emotional, spiritual or physical. And when it comes to the knee, it’s a word that you hear a lot. Over 25% of all sports injuries involve the knee (75% when it comes to surgery), and many of those involve some kind of instability.”
As I mentioned in my article, “Can Being Too Flexible Be Harmful?” (Awake & Ready! Fall/Winter 2004—Vol. 9, No. 3), it used to be rare that yoga was the “sport of injury”; now it’s more common. We are going to take a look at knee anatomy and alignment to help you to prevent knee injuries in your yoga classes and your practice, and to help those walking (or limping) into your classes already with knee injuries. Then we’ll review what one should avoid and what one should emphasize in their yoga practice and teaching.
Knee Anatomy 101
The knee is not only the largest joint in the body, but it also happens to be one of the most complicated joints as well. On the surface it appears to be a simple hinge joint—extending and flexing back and forth like a door on a hinge, opening and closing. Besides bending, the knee also has to be able to twist, move side to side, push and withstand immense pressure. The joint requires a delicate balance of flexibility and strength—a wide range of motion and stability—to do all of the tasks that we ask of it.
“Wait a minute!” some of you may be saying now. “Did you say that the knee needs to be able to ‘twist’ and ‘move side to side’? Isn’t that what we’ve always been told to avoid?” You may be surprised to learn that the knee joint should be able to move through 150 degrees of flexion, move 3–4 degrees sideways, and rotate 90 degrees as well.
Gulp! Does that make your knee hurt just thinking about it? (Visual aid: If you think of the right femur stacked on top of the right tibia, then lateral rotation is when the femur rotates laterally, i.e., “out,” relative to the tibia. Obviously, we don’t want 90 degrees of rotation while the knee is bearing weight!)
In fact, much of this movement takes place without our even knowing it. It’s when we go beyond the normal range that we get into trouble. First of all, the femoral and tibial condyles (i.e., the bottom end of the thigh bone and the top of the lower leg bone, which meet at the knee joint) are shaped in such a manner that there is “automatic” rotation of the knee every time one flexes or extends the knee. Further rotation can occur only when the knee is flexed and the ligaments are relaxed. In poses such as Rajakapotasana (Pigeon) or Padmasana (Lotus), we may be moving the (flexed) knee joint side to side within the 3–4 degree “safe” range, but we’re in big trouble if we go beyond that natural range.
So with that said, you can let what happens naturally happen, and never consciously try to twist or move your knee laterally (side to side)—or let that happen beyond the safe range due to lack of attention to alignment. In the Therapeutic Yoga Teacher Training course, under my watchful eyes (I have been called “Eagle Eyes” more than once…), we learn how to explore these movements safely. But again, we do this to understand the joint, not for the purpose of instructing others—or ourselves specifically— to attempt rotation or lateral movement in our asana practice.
Okay, so let’s continue. The three bones that make up the knee joint consist of the femur (thigh bone), tibia (shin bone) and the patella (knee cap). The main ligaments that hold the bones in place are as follows: The medial collateral ligament (on the inside of the knee) and the lateral collateral ligament (on the outside of the knee) both prevent the femur from sliding too far to either side relative to the tibia. The anterior (in front) cruciate ligament and the posterior (in the back) cruciate ligaments are positioned crossways from each other and prevent the femur from sliding too far forward or backward relative to the tibia. Perhaps you have heard someone speak of having an ACL injury—it’s short for “anterior cruciate ligament”—and now you know that his or her femur probably went way too far forward! (Theoretically, it could have gone way too far backward, but that would be a very unusual injury.) And last but not least, attached to the rather interesting bone (the knee cap) that seems just to float in space when you look at knee joints in an anatomy book, is the patellar ligament. (See figure 1).
You’re no doubt familiar with the muscles mainly responsible for moving the knee joint:
- Four muscles collectively known as the quadriceps extend the knee joint. Their names are rectus femoris, vastus medialis, vastus lateralis, and vastus intermedius (underneath the rectus femoris). (See Figure 2—left.)
- Three muscles collectively known as the hamstrings flex the knee. Their names are semimembranosus (which constitutes the main bulk of the muscle group), semitendinosus and biceps femoris. (See Figure 2—right.)
I hope this does not sound too complex so far. Stick with me as we continue.
But before going on, are any of you wondering why that little kneecap hangs out there in front of the knee joint? Is it some sort of shield?
Yes, it does indeed protect against a blow to the front of the knee joint from either a fall or an outside force. Its prime function, however, is that of a lever—a lever so effective that it enables the quadriceps muscles to lift 30% more weight than they could lift without it. The quadriceps consolidate into a tendon that runs through the knee joint and attaches to the tibia. The patella actually resides within this large tendon and prevents it from resting on the joint surface underneath; this gives the quadriceps its mechanical advantage. This system is referred to as the extensor mechanism.
In order for the patella to act as a lever and provide this mechanical advantage, it must function properly by moving up and down the knee joint in little grooves, or tracks. And you guessed it: Mine was not functioning properly when it jumped its tracks during “Knees Up Mother Brown.”
This aberration of the patellar movement (often referred to as chondromalacia, runner’s knee, or quadriceps insufficiency) can have several causes: a blow or a fall, overuse injuries that happen over time, atrophy (underuse), and degeneration of the cartilage and/or bones. However, there is usually one common thread (a better fiber to mention than “thread” would be “muscle”!—I hope you like my anatomy jokes more than my children do), and that is the vastus medialis. (See Figure 2.) In Peak Condition, Drs. Garrick and Radetsky state that simply strengthening the vastus medialis can solve about three quarters of all knee problems. Rather impressive, isn’t it?
Knee Anatomy 102
Later I’ll discuss just how to go about strengthening this wonder muscle, but for now, let’s talk about the other tissues that make up the knee joint. (I’ll bet you hoped we were done with the anatomy part. But here we’ll get into a little physiology, too—now I know you’re getting excited!)
First, there are the tendons, which attach the muscles to the bones. We’ve already talked about one of them: the tendon that contains the patella. The lower portion of this tendon connects patella and tibia; it’s called the patellar tendon. If someone has patellar tendonitis, there will be a pain specifically at the point just below the patella. Tendonitis is a general term for inflammation and irritation of a tendon. Other major tendons in the knee joint that you might hear about are the hamstring tendon (in back), the quadriceps tendon (the upper part of the tendon that contains the patella; it connects the quadriceps and patella), and the iliotibial band (also known as the “iliotibial tract” or fascia lata); it runs from the iliac crest, down over the lateral side of the knee, and attaches to the tibia). All of these can get “itis” attached to the end of their name if they are overused, abused or otherwise injured.
Now with all of this extending, bending, twisting, sliding and tracking going on in the knee joint, one would hope to find some smooth surfaces and a little lubrication to help all of this motion along. And yes, there are some! They come in the form of two different types of cartilage: the articular cartilage and the fibrocartilage (meniscus). The articular cartilage coats the ends of the tibia and the femur, cushioning them and protecting them as it creates a smooth surface for the bones to glide over. There are two menisci: the medial meniscus and the lateral meniscus. They are dense, rubbery and C-shaped, and they function as shock absorbers. The menisci also help to distribute the weight of the body evenly across the knee joint. The knee joint gets its fair share of lubricating fluids too. The joint is enclosed in a capsule called the synovial capsule, which is filled with synovial fluid. (I’m sure you remember the importance of synovial fluid to feed and lubricate joints, as discussed in my article “The Perfect Warm-Up”, Awake & Ready!, Spring 2005, Vol. 10, No. 1.) There are also many bursa sacs (filled with a fluid similar to synovial fluid) on and around the joint, which help cushion and lubricate tissues that glide over each other such as muscles and tendons over bones.
Sounds good, yes? Surely with all of this protection around the knee we should not run into too many problems with this joint. Well, think again. Remember people like me who are “too busy” to listen to knees that talk to them? Or the weekend athletes who want to go down the ski run “just one more time,” and end up trading in their ski poles for crutches. Or the couch potatoes who suddenly decide they need to get in shape, and start off doing deep squats with weights? Or the yoga student who is absolutely determined to get into Padmasana (Full Lotus Pose)? I think you get the picture.
I’ll list a few of the more common problems that can occur to the knee joint without going into the specific pathology (what is actually wrong): Sprained ligaments (e.g., ACL, MCL etc.), meniscus tears, extensor mechanism injuries (e.g., patellar dislocation, patellar tendonitis, quadriceps insufficiency, runner’s knee etc.) and of course the usual broken bones, swelling and gelling (getting stuck). I hope none of this sounds familiar to you—or if it does, I hope it’s because someone you know has it, and not you!
Instead of trying to cover the details of a lot of different injuries (come to the new version of Therapeutic Yoga Teacher Training at The Expanding Light if you want more), this article is going to focus on maintaining a healthy extensor mechanism. That’s what helps keep the knee joint stable, strong, flexible, and on track! The good news is that learning how to do that will benefit just about any knee injury that you may come across, whether you understand the pathology or not.
Preventing Knee Injuries
Prevention comes first. Leg alignment is key in both preventing and rehabilitating knee injuries. The knee quiz focused on the most common misalignments of the knee. Consistently practicing yoga (or other activities) without proper alignment can destabilize the knee joint and create extensor mechanism injuries. Once injured, misalignment will continue to stress the knee and not allow it to recover fully.
Sometimes it’s difficult for a student (or a teacher) to know exactly when the knee is straight, and not hyperextended. Finding the center of the knee joint and aligning it is one of the alignment techniques that we practice a lot in Therapeutic YTT. In the meantime, whenever there is uncertainty, err on the side of having the knee being slightly flexed, not slightly hyperextended. Being slightly flexed will not injure the knee. In fact, it will slightly strengthen the quadriceps.
In one workshop, I had a student who was a chronic knee hyperextender, with very little upper leg musculature. to her, putting her legs into alignment and holding them felt like phase one of Utkatasana (Chair Pose); her knees also felt bent. However, she could feel right away how it took the stress off her knee joints. Similarly, many of your students may say that they feel that their leg is bent when you place it in proper alignment. Let them know that as they continue to practice correct alignment, the new position will soon feel like the straight position that it is.
In all yoga positions, we want to keep the sensations out of the knee joint itself. One does not get stronger by going into the pain or discomfort of a joint. In fact, one gets weaker through destabilizing the joint. Feeling sensations in the joint is not the way to become more flexible either. Again there will be a grey zone, which it will be hard to determine if what a student is feeling is (a) the effort or stretch of the muscle and tendon that attach to the knee joint, or (b) the ligaments holding it together, or (c) the other tissues that comprise the knee joint. When in doubt, back off. Strength and flexibility can be gained without going into the extreme position. Teach your students to be like the tortoise: slow and steady to get results instead of fast and impatient, which invites injury.
Knee Tip Sheet
Here are some tips on what should be emphasized for knee injuries, and what should be avoided (which is every bit as important as what to do, if not more important in some cases). We’ll begin with several for your teaching:
1. Do not show the incorrect way to place your knees!
This may seem obvious to most, but guess how I first injured my knee? I was teaching dance and yoga classes at the time. I was getting pretty smart about alignment (or so I thought), so I would show my dance students in particular how not to do their plies (knee bending exercises), i.e., how to avoid injury by turning their knees neither too much out nor too much in relative to their foot position. Sure enough, since I showed them regularly as a reminder, I was later able to prove (in a most unfortunate way) that I was indeed correct: I demonstrated hopping on one leg while in arabesque (other leg extended straight out behind) movement, and due to the instability I had created in my knee through my demonstrations, injured my knee right there in front of them. (I told you so!)
2. Look carefully at your students’ knee alignment!
This means walking around the room to observe alignment from different angles. No hyperextension in any position!
3. Tell students that they should never feel the pose in the knee joint itself.
This is especially true in stretching asanas (in particular, those positions that stretch the fronts of the thighs) or weight-bearing with the knee(s) bent (e.g. standing poses like Virabhadrasana I and II). Now for a few general tips for those who already have knee injuries:
4. Other positions to avoid:
Twisting the knee—like Garudasana, Padmasana, and even simple cross-legged positions, all of which may put too much twist into the knee joint Balance poses—The instability of being on one leg or other wise difficult positions to maintain balance will cause the knee to potentially gyrate and be stressed. Deep flexion of the knee—like Utkatasana (second phase), Supta Vajrasana and Balasana; Maha Mudra, too Knee flexion with hyperextension of the hip joint—like Supta Vajrasana, Dhanurasana and Natarajasana Pressure on the knee—e.g., Table Pose, Ustrasana or Parighasana (Gate Pose) Inversions that one could potentially fall out of and land awkwardly, stressing the knee—e.g., Sirshasana (Headstand) Medial or lateral rotation—e.g., Supta Virasana encourages lateral rotation (this pose is like Supta Vajrasana, but with the heels out to the sides of the buttocks rather than directly beneath them); also, any Rajakapotasana variation encourages medial rotation.
5. Do asanas that strengthen the upper legs
The safest one is probably Salabhasana (Locust Pose), which strengthens the hamstrings. Utkatasana leaning against the wall, with only a little flexion to begin with (never go beyond a right angle), strengthens the quadriceps. (See photo at right.)
6. Strengthen the vastus
medialis muscle (VM) This is the inner thigh muscle near the knee (see Figure 2; see also Isometric Strengthening of the Vastus Medialis). It is the most important muscle to strengthen to help with the healing and prevention of knee injuries. During Therapeutic YTT we spend a lot of time locating this muscle and activating it in various positions. In the meantime, just isolating it as described in Isometric Strengthening of the Vastus Medialis will help to bring relief to students’ knees.
7. Give it a rest
Use legs-up-the-wall pose, with or without the hips supported on a folded blanket. This not only gives the knees a rest, but also it helps reduce inflammation by keeping the knees higher than the heart. Support the knees with a bolster during deep relaxation as well.
Did you notice that, in the not-to-do list, Supta Vajrasana was mentioned twice? This was no accident! Vajrasana (Firm Pose) could have been added several places as well. These positions put a tremendous amount of stretch and pressure on the knee joint. They are often the culprits behind a knee injury from hatha yoga practice. For more on this see my article “Can Being Too Flexible Be Harmful?” (Awake & Ready! Fall/Winter 2004 –Vol. 9, No. 3).
Does this mean that you can never do these and other potentially knee stressing poses if you either want to avoid knee injuries or have had one? No, but some people may need to avoid them if the poses always put stress on their knees and if their knee(s) never fully recovers. Or they may need props to be able to do certain poses safely.
The key to going back to an optimal yoga practice is keeping the vastus medialis strong. Not just during the rehabilitation period, but forever afterwards. I regularly isolate and strengthen my vastus medialis. And if I forget, well, my knees talk to me, and you can bet that I now listen to them, even if they just whisper! When I hear them, I contract (my vastus medialis that is)! In fact you just might see me driving down the freeway—awake and ready—chanting to Crystal Clarity’s new Power Chants CD, and you may wonder how I keep time to the music (well, maybe some one person out there might be wondering…). Well, here is my secret: I alternately contract my left and right vastus medialis muscles to the beat. And just thinking about that music has got me rhythmically contracting my VM’s right now as I type this article—left, right, left, right…
Integrating yoga therapy into one’s daily life is key to preventing re-injury as well as moving forward spiritually. Not that I recommend that anyone try this while driving (unless they are really, really sure that they can handle the car—first try it while typing at the computer without slowing down). After all there are many other ways to strengthen the VM, and integrate yoga practice during the day. Be creative as you keep on track with your knees, chanting and other yoga practices!