Recently, I was instructing my students on looking after their knees in hip-opening asana. I said, “Do you know anyone who is pretty inflexible in how they like to do things, is very sensitive, tends to hold a grudge if you do something they don’t like and if you hurt them they may even never forgive you for the rest of their life?! Your knees are like that!”
Knees are so sensitive because they are in a vulnerable position. They are the “piggy in the middle” between your very flexible, adaptable, easy-going foot and your stable, resilient hip. Your knee is the most susceptible joint in your body to osteoarthritis (the wear-and-tear type) because it moves the most of all our joints. Much of this movement happens inadvertently when it transmits the forces from your foot to your hip. Although as a moveable joint it prefers to only hinge, i.e. flex and extend, instead it takes the brunt and absorbs many other movements that the foot and hip joints can easily perform or that they do not perform. This is especially the case in postures designed to open the hips.
In this article I would like to focus on pain on the medial or inside area of the knee joint. It is only when medial knee pain is directly within the joint that it can be more serious, as in that it may require long-term rehabilitation or possibly surgery. Especially if there is swelling of the joint one can presume that the problem is inside the joint capsule. Inside the joint capsule are the cruciate ligaments and the menisci. The joint capsule retaining fluid to protect these structures is what we experience as swelling. Damage to any of these structures requires long-term healing and rehabilitation or surgery.
Knee Pain ≠ Knee Problem
Unless you have specifically injured your knee, most knee problems are not problems of the knee joint itself. Really? Yes, really. You may feel the pain or discomfort at your knee but the problem often comes from the pelvis. Did you know that there are twelve muscles whose tendons cross the knee joint? And ten of these muscles attach to the pelvis. For those budding anatomists they are the four quadriceps, three of the hamstrings, the gracilis, sartorius and tensor fascia latae. When you look at these muscles you will see that they surround the pelvis and act as guy wires that cross the knee joint and anchor or stabilise the pelvis in relation to the leg. From this vantage point it is easy to imagine that any misalignment or imbalance of the pelvis will change the tension in these ‘guy-wires’ and cause stress on the knee joint. At extreme ranges of motion, e.g. a half or full lotus, these stresses are enhanced and this is when an imbalance that is otherwise not noticeable, may result in discomfort or pain.
The Goose’s Foot
Three of the ten muscles mentioned above attach to the tibia or shinbone on the medial or inner side of the knee. The tendons of these three muscles (sartorius, gracilis and semitendinosus) co-join to insert along side each other in what is known as the pes anserinus or goose’s foot. Between them they perform every action that is possible at the hip joint! Sartorius attaches at the front of the pelvis (the ASIS) and contributes to all the actions that allow us to sit cross-legged (hip flexion, abduction, external rotation and knee flexion). Gracilis originates at the pubic bone and performs adduction, flexion and internal rotation of the hip as well as aiding knee flexion. Semitendinosus, one of the hamstring muscles attaches at your sit bone and performs hip extension, medial rotation and knee flexion. An unbalanced pelvis will inevitably cause tension in at least one, if not all of these muscles. With their common insertion on the inside of the shin bone (tibia) this means that the tension is usually felt here or where they cross on the inside of the knee. In the case of semitendinosus the tension is sometimes right behind the knee on the medial side.
The pelvis on the ‘sore knee’ side is often tilted backward (posterior). In this position the hamstrings are shortened and the sacrum is counter-nutated. This sacrum-pelvis position takes the leg into external rotation. Although this is the initial movement we do in order to take our leg into a half lotus, the deepening of these hip-opening postures requires internal rotation of the thigh in the hip joint. With the leg externally rotated the knee will often sit off the floor and folding over the lotus leg into a forward bend, which requires greater internal rotation, will aggravate the knee tension or pain.
If this imbalance is longstanding, the extra tension in these muscles can cause an irritation of the pes anserine bursa. A bursa is a fluid-filled sac underneath tendons that reduces friction between the tendon and the bone beneath it. Bursae are highly innervated which means they signal pain! In fact, they do this much more efficiently than the menisci, which are most often blamed for medial knee pain.
This is the sort of knee problem that is worse on some days, better on others and may even disappear completely, seemingly of its own accord. In this case the pelvis has somehow realigned itself and with restoration of the balance of the muscle guy-wires that cross the knee joint, the pain is naturally relinquished. If you suspect your knee pain is not meniscus or ligamentous in nature, this is one time when you need to seek the help of a professional musculoskeletal therapist. A good therapist can unwind your pelvis and give you corrective exercises to maintain the muscle balance needed to hold the pelvis in equilibrium.