Sunday, February 6, 2011

What Lies Beneath (Our Bums): Observing the Hip Joint to Protect the Knees

“The Day My Bum Went Psycho” is a book written by Australian children’s author Andy Griffiths.  It’s a story about detachable bums that jump off their owners.  Zach, the main character, wakes up one night bumless and has to get help from some bum-hunters to recover his rogue bum, which has become the leader of a group of bum scoundrels that have set out to rule the world. 
If you actually removed your bum, or what most of us thought of as our bums, you would probably be removing the fat that is stored there along with large muscle that almost everyone knows the name of—the gluteus maximus.  Removing this muscle would make some things very difficult or awkward, such as walking and running or getting up from a chair. 
Now, we know the gluteus maximus is big and important because if someone had named you Samantha Maximus or Tilak Maximus it was probably not without reason.  But if you removed your gluteus maximus (for example if your bum went psycho) you would find some other very important muscles called external rotators.  You can see the people who named our body parts are in fact very clever because, as you could probably guess, it is their job to perform a movement called external rotation at your hip joint.
Understanding the basic movements at your hip joint is important for deep hip opening postures and, understanding external rotation in particular, can help prevent injury to the knee joint in some of these poses where you also need to bend your knee (think lotus, pigeon etc).
In this blog I want to talk about the six basic movements of the hip joint and then focus on the idea of external rotation in the context of protecting the knee joint.  Hip opening postures are sure to give even the most open-hipped yogi a little pain in the butt.  Practicing with awareness and alignment will also help you protect your knee joints.
Hip joint & its movements
There is no hip bone.  There is a hip joint.  The hip joint is where your femur (thigh bone) meets your pelvis.  Now, if I asked a group of random group of people to put their hands on their hips, they would most likely put their hands on their waists, just about the top of the pelvis.  But your hip joint is much lower and is almost level with the bottom of your bottom. 
The hip joint is a special joint known as a ball and socket joint.  This is because the top part of your femur is ball-like and it fits neatly into the socket (acetabulum) of the pelvis.  This ball and socket configuration is important as it means the hip joint can move around in many directions (unlike your knee for example, which is a hinge joint and essentially just bends and straightens.  
Hip Joint

You can see how much mobility the ball and socket joint gives your hip when you consider that it has 6 basic movements (compared to the 2 basic movements of the knee).  These basic movements are:
1.       Flexion (e.g., bending your knee and bringing your thigh into your chest)
2.       Extension (e.g., in standing take your thigh out straight behind you)
3.       Abduction (e.g., in standing take your thigh straight out to the side away from your body)
4.       Adduction (e.g., in standing take your thigh straight in towards your body so that it crosses in front of or behind the other leg)
5.       External rotation (e.g., with a straight leg, turn your thigh out so that your toes point away from you)
6.       Internal rotation (e.g., with a straight leg, turn your thigh in so that your toes point towards you)

Basically, you could classify any asana where you performed one of these actions as a hip opening posture, which sort of leaves you with almost every yoga posture and you can see why tight hips might make your practice tricky!  However, the deep hip openers are usually the ones that place your joints in greater extremes of movement (think extreme lunges and splits (forward and sideways), pigeon and its variations, as well as lotus and its variations). 
It is also important to remember that you rarely do just one of these movements at once.  Typically, when we say we are doing hip opening postures in yoga, we are doing more than one movement at a time. For example, if you did Vrksasana (tree pose—see picture below) you have simultaneously flexed, externally rotated and abducted the hip joint of the raised leg.


The Pelvis & Knee Joint
From the description above, it sounds like all you need to do to do in hip opening postures is to move the thigh bone in a particular direction.  But it is never that easy. 
First, the hip joint consists of the femur and the pelvis, so when doing any hip opening posture you need to be mindful of the movement of your pelvis as the movement of the pelvis can enhance or diminish the hip opening you are trying to cultivate.
In general, whatever the posture, you are always trying to move your pelvis in a way the brings it towards restoring the natural curve in your lower back (called the lumbar curve) so that your lower back feels long and, importantly, free.  Here I note that this is even in poses where it looks like your spine is curved.  This is because while outwardly your spine might look rounded, internally you are still trying to do something in your body to find length and return to your lower back to its natural curve.  This is particularly true of forward bending but is also true of backward bending.
Second, at the other end of the femur is the knee joint.  As a general rule your knee joint should only bend or straighten (flex or extend) when you do hip opening postures.  You should not twist your knee joint.  You will probably know if the knee joint is twisting because you will feel pain—often on the inside of the knee joint itself.    Any time you are in a hip opening posture you must stay mindful that you are not experiencing twisting or pain of the knee.  This is easier said than done, especially if some of your hip muscles are tight, as we will see below.
Protecting the knee
The knee is susceptible to twisting forces if you do not position your hip correctly, particularly when the knee is bent.  Let’s think about a position I have been doing a lot of in class lately—agnistambhasana (fire log pose).

 In order to achieve this posture you need to flex at your hip joint.  No real problems there—if you can sit on a chair you can probably achieve that. 
Next, in order to get your ankle on your opposite knee, you need to abduct the thigh and externally rotate it.  The external rotation is the really important part.  If you cannot rotate the femur enough in the hip socket, you will have no chance of getting your foot onto the opposite knee—safely or at all. 
If you do not have enough external rotation in your hip joint and you persist in trying to get your ankle over to your knee, you will force unwanted movement either into the pelvis or the knee.  In the pelvis you will notice this because you will start to round your lower back and slump in order to compensate for the lack of movement at the hip.  In your knee you will find that the shin bone starts to twist and place pressure on the inner knee. 
In both of these scenarios you might end up with your foot where you think it should be but the accessory movements of the pelvis and at the knee joint that you have created are undesirable and even unsafe.  For those with lower back problems you will create undue pressure on the lumbar spine and for those with knee problems you will feel acute pain.  Even if you don’t have knee or back problems, practicing like this might create them. 
The wise and mindful thing to do is to stay alert to what is happening to the curve of your lower back and the feeling in your knee joint as you practice any hip opening posture and ask your teacher for an alternative position if you notice your body going astray. 
For some people who are able to get their ankle across their knee and feel some strain in the inner knee joint, you could also try to grasp the whole thigh bone on the side where the knee is hurting and externally rotate it (roll the whole thigh out and away from you).  By doing this you might manually create the extra rotation that you need and your knee pain will dissipate.  If it does not, then come out of the posture.
External Rotation In Other Postures
You can apply this principle of awareness of the movement of the thigh bone, and the external rotation in particular, to other postures. 
For example, in warrior II (Virabadhrasana II) or triangle (Trikonasana) you can watch that the knee of the front leg continues to point directly over your toes.  For some people the knee will drop in and you can resolve this by trying to externally rotate your front thigh.   If your hips (and especially your inner thighs) are tight, what you will probably notice is that the back hip moves when you do this, and that is fine, let it (it will probably come forward and around a bit because there is now too much stretch on the inner thighs, which might have been the reason your knee dropped in the first place).  The more important issue is always the integrity of your knee.
You can apply the same principle in sitting postures such as lotus (padmasana), pigeon (eka pada rajakapotasana), janu sirsasana etc—basically all of the postures that require you to bend the knee and externally rotate the hip at the same time.  You just need to make sure that you are correct in understanding the actual movement that is going on at the hip joint.  For instance, some postures (like virasana) require internal rotation at the hip joint so you would not want to use this technique in those!  Ask your teacher if you are not sure.
For more reading on this topic check out this article
Happy and safe practicing!


  1. Hi Sam

    Not sure if I have already written to you or not, but figured out twice is better then not at all so here we go. Thank you heaps for your amazing blog. It is a real treat and im always exctied when its agian "that time of the week" :-)

    Keep up the good work and hope to c u in one of your classes soon.


  2. hi, nice blog and nice post.
    Take this with a grain of salt but I would suggest two other actions for the hip joint are compression and decompression. I'd suggest that decompression may help in a lot of hip stretches by creating space between thigh bone and pelvis. Muscles that create that space are obturator and gemellus.

    Compression could be used when you are trying to stabilize your hip joint.

    all the best, neil

    1. Thanks Neil. It took me a while to see your comment. I think I understand your point, although I am no expert! Appreciate the feedback.