Learn about your knees
(So that you can use your body more effectively and deal with problems like knee pain)
Published: 2020 01 16
Updated: 2020 06 16
We tend to think that all the knee joint does is bend and straighten. But the knee does a little bit more than bend and straighten. When the knee is bent, the knee joint actually allows the shin to rotate relative to the thigh. However, this ability is restricted when the knee is straight.
Why is it important to understand this simple idea?
There are muscles that can be used to stabilize the shin, to prevent it from rotating. These same muscles can also be used to deliberately rotate the shin. So as well as being able to use "knee muscles" to bend and straighten your knee, you can also use knee muscles to rotate the shin relative to the femur or keep the shin rotationally stable relative to the femur.
And so what happens when the knee is straight?
If these muscles work to rotate or stabilize the shin against rotation, what purpose do they serve when the knee is straight? Well, then they can be used to help rotate the shin and femur together relative to the hip joint.
So why do the knees allow the shins to rotate?
Because the shins can rotate at the knees when the knees are bent we can squat with our feet at varying distances apart. It also allows us to easily adjust foot position when one or both knees are bent and supporting our body weight. In terms of yoga poses, it allows us to use leg positions like the various janu sirsasana variations as well as virasana and lotus.
The ability for our shins to rotate at the knees is a way of allowing us to use our legs with greater flexibility. It allows us to use our feet in more ways without putting undue stress on our knees. And so one idea here is that if you want to look after your knees (or help keep them pain free) practice controlling them through all their ranges of movement.
Learn about your knees Index
With respect to the knee (and most, if not all other joints of the body) there are muscles that only on the knee and there are muscles that act across the knee and other joints. You can get an overview of these muscles in knee anatomy for yoga teachers.
In a nutshell, the single joint muscles that work on the knee joint include the three vastus muscles (which are part of the quadriceps group), the popliteus and the biceps femoris short head. The multijoint muscles that work on the knee and the hip joint include: tensor fascia latae, superficial fibers of the gluteus maximus, sartorius, gracilis, semitendinosus, semimembranosus and biceps femoris long head. Multi joint muscles that work on the knee and the foot include the gastrocnemius and plantaris muscle.
Perhaps one of the most important things you can do with respect to keeping your knees healthy is learning how to stabilize the knee.
At the most basic level you could stabilize the knees by making them feel stiff. However, an important consideration is whether you are stabilizing the knee to resist rotation, resist hinging (bending or straightening) or a combination of both.
Another important consideration is whether you are working from a stabilized foot and ankle or from a stabilized hip bone, or from a stabilized femur.
To find out more about the different knee stabilization options and the muscles that can create those different kinds of stability, read knee joint stability
For more on shin rotation and the muscles that cause it (and the muscles that you can use to stabilize against it) check out knee rotation. Also check out Shin rotations and heel stability for a look at shin rotation relative to the foot.
The sartorius is a muscle that works both on the knee joint and the hip. Because it works on two joints, there are a number of ways in which this muscle can function. For a look at the various functions of the muscle in the context of different leg actions and yoga poses, read the Sartorius article. Because the functions of this muscle are varied, potential problems with the sartorius are varied. However, some simple approaches to dealing with sartorius problems include making sure that the ASIC is anchored. In addition, making sure that the foot is stable. An overview of those points and more are included, along with some variations of warrior 1 that you can use it to both to stretch and strengthen the sartorius muscle. Read more about stretching the sartorius in: Sartorius stretch, warrior 1.
As mentioned, the three vastus muscles are part of the quadriceps group. They are single joint muscles that work to straighten the knee or to help it resist bending. These muscles all underlay longer muscles which I term the long hip muscles. And so as well as working on the knee joint, another possible function of these muscles is that of adding tension to the overlaying long hip muscles.
Read more about these single joint knee muscles in Vastus Muscles
For reasons why you have difficulty activating your quadriceps read: how to activate your quads.
The IT band is a band of connective tissue that runs down the outside of the thigh. It connects to the hip crest and from there reaches down to attach to the outside of the tibia just in front of the fibula. In so doing is passes over the vastus lateralis muscle. Two muscles that act on it from the hip bone are the tensor fascia latae and the superficial fibers of the gluteus maximus.
The IT band can be a source of knee pain where it inserts into the tibia. To find out possible solutions for IT band knee pain, read the IT band knee pain article.
For more on the IT band itself and how the muscles that work on it can be used to either rotate the shin or stabilize it against rotation (with other muscles), check out the IT band anatomy biomechanics article.
The long hip muscles are how I collectively refer to the muscles that work on both the knee and the hip joint. These muscles attach to the corner points of the hip bones. And they, bar one exception, attach to the inner and outer aspects of the lower leg bones.
These muscles can be very important for stabilizing the hip bone. But in addition, they are also very important for keeping the knees safe, both in normal every day use but also when doing extreme yoga leg positions like hero pose and lotus.
Find out more about the long hip muscles and get a taste of how you can use them effectively to help keep your knees healthy in the Long hip muscles article.
Among the long hip muscles are muscles that work to flex the hips. These muscles include the sartorius, rectus femoris and tensor fascia latae. These muscles all attach at or near the ASICs. And they all work on the knee joint in slightly different ways. While the rectus femoris works to resist bending of the knee and may help to straighten it, the sartorius can work to internally rotate the shin while the tensor fascia latae can help to externally rotate the shin.
So that all of these muscles can work effectively on the knee joint, it helps if the ASICs is anchored. And to that end it helps to understand how the ribcage and spine (and even your mood) can affect the knees. Read more about that in Knees, spine, ribcage and mood.
For a slightly different take on how to anchor the upper end of these muscles read knee pain.
The stage was set for me to learn to fix my own knees when I damaged my medial collateral ligament in a motorcycle accident. I've had various knee pains since then and a big part of fixing my knees, apart from time, has been learning to understand how the knees work but also learning to feel and control the muscles that act on the knees. Read more about both in medial collateral ligament pain
It's taken me a long time to fix my knees. Ideally the information in the articles above will help you work more efficiently at fixing any knee problems you have.
For simple exercises that include learning to feel and control a large portions of the knee muscles just mentioned, take a look at the Smart yogi PE program. PE stands for proprioceptive elements.
For myself, now that I can feel and control my knees and the muscles that work on them, the most important thing is using them. I do simple exercises where I can maintain focus on feeling my knees, so that I can prevent injuries from happening. I'll be writing more on the knees, but another important element to look at for better knee health is the lower back. I've written a lot on the various elements of the lower back (it includes the hip bones) and you may find that improving your ability to feel and control the muscles of your lower back makes it easier to look after your knees.
Ironically, the Smart yogi Proprioceptive Elements program also includes exercises for helping you to learn the muscles of your lower back also!
Now that I've got the attempted at sales out of the way, for some of the exercises that I used to keep my knees healthy, check out knee strengthening exercises. These include the general muscle activation instructions that I use in my classes (after first teaching students to feel those activations).
My youtube videos that relate to knee health and keeping knees healthy
Watching videos on youtube isn't everyone's cup of tea, particularly with the ads, but none the less, here's a collection of my youtube videos that detail the a fair few of the techniques I've used to deal with knee pain, check them out here leg and knee strength exercise videos.