Cowface/Gomukhasana/Shoelace: is it internal or external rotation of hips?
This is a question that comes up rather frequently. Are the femurs in Gomukhasana (aka Cowface or in Yin Yoga called Shoelace) internally or externally rotated in the hip sockets? The correct answer is — external rotation. Let me explain why.
When I first began teaching yoga, I too thought that the femurs were internally rotated in Cowface pose. But, as I learned more about anatomy, I came to realize that I was confusing adduction for internal rotation. Cowface can not be done when the femurs are internally rotated, except by some very flexible and strange bodies. There are 3 ways to illustrate Cowface’s external rotation:
1) There are three postures that are part of a family of hip flexions and external rotation: Butterfly, Square and Cowface/Shoelace.
Sit in Butterfly and notice what is happening at the hip sockets. The femurs are flexed (you are sitting with the legs about 90 degrees flexed to the pelvis), adducted (the legs are apart) and externally rotated (the knees are lateral to the feet, sometimes this movement is known as lateral rotation.) I think everyone would agree that in Butterfly the femurs are flexed, abducted and externally rotated at the hips. Now, slide the knees closer together, allowing the feet to go medially past each other, into Square pose (aka Firelog, 90/90, or Double Pigeon pose …. so many names!) The only change you made was to reduce the abduction of the legs: in Square pose, the legs are almost or totally neutrally abducted BUT the femurs have not changed their flexion and external rotation. Square Pose is an external rotation pose.
Now, from Square pose continue to move the knees inward until they are on top of each other. Allow the feet to continue to move away from each other. You are now in Cowface pose. The only thing you have done is adducted the legs. The femurs are still externally rotated and flexed at the hips. Even though the feet are now past the midline of the body, this does not change the rotation of the femurs at the hips. It is simply adduction of the legs. Cowface has externally rotated femurs.
2) I believe everyone would agree that Lotus Pose (Padmasana) involves external rotation of the femurs at the hips. Well, if full Lotus is external rotation, certainly Half Lotus is as well. Consider the top leg in a pose where that foot is resting in Half Lotus on the thigh of the opposite leg and that opposite leg is straight. (In Ashtanga, think of Ardhabaddhapaschimottanasana. In Yin Yoga, we call this Half Shoelace! You could call it Half Cowface if you like.) The top leg in Half Lotus is externally rotated, so the top leg in Half Shoelace is externally rotated too! Allow that leg to come further to the midline of the body: it is now exactly where the top leg is in Cowface! If the top leg in Lotus is externally rotated, so is the top leg in Cowface. The same logic will show the bottom leg is also externally rotated.
3) Finally, let’s assume that Cowface actually did involve internally rotating the femurs at the hips socket (even though it doesn't). If we can prove that this is impossible to do, then we will have proven that the femurs are actually externally rotated.
Sit in Virasana: sit between your feet and widen your knees as far as you can. This is sometimes called W-sitting and it is fine if you have the bones for it. If you do not, and feel pain in your knees, please skip doing this pose and just read about it. In Virasana with the knees apart your femurs are abducted, flexed and internally rotated at the hip sockets. If Cowface was adduction, flexion and internal rotation, it should be pretty easy to get there from Virasana. All we have to do is bring the knees on top of each other. Slowly try it. Begin with bringing the knees together. This eliminates the abduction. But, for many people this hurts their knees because their boney anatomy won’t allow this position. Some people can do it, however, so if this is you — see if you can come to the final stage. Keeping the feet outside the hips (because that is internal rotation!) stack the knees on top of each other. It can’t be done! (At least for me, it can’t without breaking my knees, and my hips are pretty average.)
In my book Your Body, Your Yoga, I go over the structure of the femur and pelvis and show that we are stopped in rotation movements by the neck of the femur impinging upon the lip (labrum) of the hip socket (acetabulum). Due to the acetabular angle of abduction of the pelvis (ie: the hip socket is not vertical but angled so it faces downward), the more we flex and adduct the femurs, the more room we have for external rotation before the bones hit. However, with internal rotation, the greater our flexion and adduction of the legs, the less room we have before impingement arises. Sitting in Virasana flexes the hips 90 degrees. To stack one knee on the other increases the amount of flexion for that top leg, which reduces the amount of internal rotation available. As draw the legs further into adduction, we reduce even more the amount of internal rotation available, which is why almost no body can do Cowface with internally rotated legs.
With externally rotated legs, Cowface becomes easier when we flex the hips more (ie: lean forward and you may find that your knees complain less and you can externally rotate more) and when we adduct the legs more. This is only possible because Cowface involves external rotation of the legs in the hip sockets.
I hope this helps to clear up this mystery!
Cheers
Bernie