This week it is time to fall in fascination with your own knees!
The subject has become close to my heart because dancers usually sight knee joint pain as a reason to stop coming to class – either in the short term or in the long term and Yogi’s often find it difficult to get up and down from the mat if the knee joint is not what it once was in terms of it’s ability to haul them up from the floor.
Just to keep us entertained, you will be interested to find out that the knee is one of the more complicated joints as the two longest bones in the body (the femur and the tibia) meet at this junction along with the Patella (knee cap). The fit of the long bones at the knee joint looks very strange on a diagram, like pieces of a jigsaw puzzle that have been forced to go together by a child over eager to finish the game! Looking at it, it is not surprising that knee pain is as common as back pain and when you consider what we expect the knee joint (and all the surrounding muscles, ligaments, tendons and connective tissues) to take an awful lot of load for us as well as dealing with all the twists and forces acting on it in every day life.
In our classes about the knee joint I hope that we can all get some insight into how to strengthen and mobilise them in order to keep them in tip top condition. I have avoided doing things that compress the knees in class because I have a dodgy (note the technical terminology here) left knee myself (and am currently newly nursing a sore right knee) and see putting people through things that put strain on the knees as a generally bad idea. Particularly twisting actions! This is the reason why I don’t teach standing poses with the traditional back leg turn out – as it puts unnecessary torque on the back knee as it over rotates the pelvis.
When the knee is injured due to a twisting action – during which you feel a pop in the knee joint – it is usually the Anterior Cruciate Ligament (ACL) that is damaged. A sports injury specialist will sort you out in this case. In the worst case scenario, it is torn and requires repair. This requires the help of a surgeon. With a more simple injury to the ACE you will be able to straighten your knee after a few days but if the meniscus is involved, you won’t.
For those of you with pups, please look after their Cruciate Ligament by NEVER THROWING A BALL FOR YOUR DOG as the risk of a tear (when your precious hound uses the joint to bring himself and the ball to a screeching stop will twist the back of the knee) requiring surgery and a year of being crated and miserable is much higher than you think.
We also need to be mindful of the state of other joints above and below them (which is why we will also be releasing hips and ankles in class this week). Very often in Squats or any hip flexion I see folk’s knees heading in toward the midline (we call this knee valves) without the person being aware of the malalignment until it is pointed out to them. In this case, the knee falls inward because the hip or ankle or both are internally rotated. The ankle falls inward when the arch of the foot is collapsed which is common in around a quarter of the younger adult population and more prevalent in the older age group. The hip is weakened when the glutes cannot hold the external rotation of the hip. In class we will work to strengthen the hip rotator muscles in things like clamshell and increase the ankle mobility and dorsiflexion.
Without strength in the muscles surrounding the knee, the joint is vulnerable. As you can see from the picture on the left, many of the muscles above and below the knee attach right under or above the joint. Notice in the picture on the right, how the Rectus Femoris muscle, the giant quad running right down the centre of your thigh actually goes over your knee cap and keeps it stable – so it’s important to fully straighten your knee say, when coming out of a squat position in order that the knee cap gets fully back in it’s rightful place! Not being able to straighten your knee fully is a sign that you have an injury and or osteoarthritis in the joint. Even with mild injuries some loss of range of motion is common. In the case of meniscus tear, known as bucket handle tear, the knee will not be able to straighten and you will feel as if something is caught in the knee (the bucket handle which is meniscus flipped into the centre of the joint). Surgery is required to fix this in most cases.
However hyperextending the knees if you are hypermobile will potentially lead to lock knee syndrome and certainly to hyperlordosis of the spine. Essentially you need to be able to lift the knee cap in standing with straight leg. If you can’t, they are probably already contracted. If they are continually and chronically contracted, the blood flow to the muscles is decreased, the quads are compressing against the femur and the joint which decreases your mobility and adds to friction which can lead to arthritis in the knee joint. Check to see whether you can stand without clenching your bottom and without gripping the quads at the front of the thigh.
When walking, it’s important not to lock the knees. The bones of the lower and upper leg should be sitting directly on top of one another, rather than hyperextending beyond the normal range of motion. Taking shorter strides will help you stop hyperextending if you have this tendency. More steps will give us more efficiency when walking and especially when running. In the photo above, the running style is very inefficient. Try to keep your legs under the body, never allowing the foot out in front as this photo shows. Kick your heels up behind you and aim for a faster foot cadence, landing on the mid or forefoot. As you can see in the photo, the foot is acting as a brace. Landing out in front like this causes heel striking which is VERY BAD for the knees and the impact ricochets up the spine causing pain and increases the risk of ‘shin splints’.
Posturally, those set in the ready-to-go Green Light Relex will notice they are often locked back in the knee so if you know you have this movement pattern, remind yourself to soften the knee which will help realign the tibia and femur. This reminder is especially important when standing for long periods when this locked back position can become a habit which eventually unfairly loads the lower back. If you have back issues, it can be very helpful to have a bend in the knee when transitioning from one position to another since it will distribute the weight from the back to the legs. A bend in the knee can also help point it in the right direction in standing poses such as Warrior and Triangle which is why we always go into them with a knee bend (to avoid torque and twist on the knee). Deep flexion in the knee is good to avoid if you have knee issues as this puts a lot of pressure on them. For instance, in child’s pose, the angle of the femur and tibia is too close but propping your bottom up on a cushion can ease knee pain as the angle is less tight
We need flexibility in order to adapt to faults or differentiations in the ankle, foot and hip actions of our individual body. When joints, muscles, tendons, ligaments have SMA (Sensory Motor Amnesia) or any kind of damage or imbalance, this necessarily involves the knee which often receives the force from above and below and ends up damaged.
As we have previously noted, squatting is much more common in Eastern cultures from whence Yoga came (for relaxation, toileting and other purposes) and it isn’t surprising that sitting in Lotus is therefore much more accessible in these cultures where SMA in this area is less likely to set in. When we attempt a squat, you will notice how ankles and hips also join in the party during the action. You cannot just bend the knee on it’s own, there is necessarily a chain reaction. Knees are responsible for helping us to walk straight and efficiently manage our gait but of course the position of the foot (for most of us it is pronated or flopping inward) will have a knock on effect with how the knees are able to manage this seemingly simple action.
Normally when we first lay on our mat I will draw your attention to the turn out in the foot when the legs are straight out from the hip. During our knee-focused class we will include an observation of the knee cap (patella) in an attempt to become aware of it’s directional bias as it may not necessarily follow the foot position. Most of us now understand if our tendency is to have an exaggerated curvature in the lower back or if we have lost some of our natural low back curve. Either way, the knees are going to be affected by the force of this unnatural balance of the hips. There is also the possibility that issues both above and below the knee are affecting it’s action. Whilst standing, you can certainly see that if you lift your toes and take your weight backwards, this has an immediate effect on the knee joint even though your brain has given no instructions to it specifically. It reminds me of the way your body is aware of how much internal engagement is required say, in plank pose, for the trunk muscles, without you having to specifically switch them on.
Anatomically, the knee is made stable by the cruciate ligaments; the meniscus and the collateral ligaments which also help support the movement of the knee. These ligaments can sometimes become strained and dysfunctional in varying degrees with a grade 1 tear being fairly common. In this case, the person will experience both pain and tenderness but they may feel little or no heat or experience little or no swelling. If these are present, the type 2 tear is then more likely which also not surprisingly involves more pain. Tears create instability in the joint and the knee is then wobbly and weak which will often curtail the person’s activity levels which only serves to deepen the problem which may lead to surgery without the correct intervention.
The Medial Patellofemoral Ligament acts to secure the patella and this is sometimes cut to prevent medial displacement of the patella following damage to the lateral patellofemoral ligament.
The synovial membrane of the knee is the inner aspect of the knee capsule, which produces synovial fluid to aid in the lubrication of the knee joint. It is also reflected on to the aricular margins of the femur, tibia and patella. It does not cover the menisi or the cruciate ligaments posteriorly and is separated from the fibrous capsule by the popliteus tendon. There is approximately 0.5ml of synovial fluid present in a normal knee joint.
The menisci help cup the knobbly ends of the femur which creates stability and has a shock absorbing capacity. They move and are flexible which helps in movement of the knee. The menisci can also tear when under too much compression or when movement causes too much friction. The injury will often be accompanied by an audible click or pop at the injury site. Over time, small meniscal tears can break off and float around the knee which presents as crepitus (cracking or clicking sounds) or even a locking of the knee joint. Long termly, this will contribute towards arthritis of the knee joint.
The knee joint is covered in the Articular Capsule which is a sac enclosing the articulating ends of the bones which participate in a synovial joint. It contains an outer fibrous layer and an inner synovial membrane. The inner layer secretes synovial fluid and is composed of loose connective tissue with a free smooth surface that lines the joint cavity.
Everybody has a different shaped femur and this could be a determining factor in how yours functions… Just like the top of the femur and the twist that is possible down the shaft of it which will both determine the turn out that you like in your feet in standing or while doing a squat. Women also prefer a turn out in the feet in terms of natural standing position because their pelvis is wider, which causes the femur to hang inward unless the feet are turned outward. Usually men find it easier to stand with feet straight, hip width apart which is why Yoga, which was invented by men, generally asks this of us. Well… in an ordinary Hatha Yoga class that is ha ha!
The problem of externally rotated femur causing a turned out foot position is that when we walk we continue this positioning, known as “out toeing” or “duck toes”. If left unaddressed, this walking abnormality can lead to knee and back pain, ankle injuries, and flat feet. Sometimes the overpronation can influence the gait so the turned out toe gait comes from the lower extremity upwards. Being duck footed can put a lot of additional stress surrounding joints and ligaments or set the stage for injury, including plantar fasciitis due to the additional strain on the fascia.
Even though the knee is described as a hinge joint, it has the action of flexing (ie when the ankle comes up toward the bottom), extending (ie straightening) and a small amount of rotation (so not just a simple hinge then). The knee is able to rotate more when it is flexed. Rotation of the feet comes from the hip if you are sitting with your legs straight out in front of you but if bend your knee, the rotation of the foot can come from the knee and is a relatively easy maneuver. The rotational movement is however a troublesome one for the knee.
The action of the knee is instigated by the brain which calls for action in the surrounding muscles. Tightness in these muscles can of course have an affect on the knee. For example, if your IT band is tight (the muscle running down the outside of the thigh), the patella will have difficulty tracking back into place and you may suffer from “jumpers knee” as I did when I first started taking on exercise as my full time job and my body wasn’t prepared for the shock!
It can be difficult to create motion at the knee joint without creating compression once arthritis has set in. One of the most simple exercises you can do is simply dangling your legs when you are sitting on a table and swinging them back and forth to allow the joint to decompress (make space). It’s even more effective to add weights like this: