Leg-behind-head postures are some of the most important, effective and beneficial yoga postures. They open the hip joints, a work that will continue later on through the extreme hip rotations. This process is essential in releasing life force from its reservoir at the base of the spine, it’s ascent leading to divine involution.
Leg-behind-head postures are also instrumental in developing the organs of the thoracic cavity, viz the heart and the lungs through producing a strong oscillation of intrathoracic pneumatic pressure and the weight that they make the ribcage strong and supple through weight and pressure that they apply.
Finally, together with back bending, leg-behind-head postures return the spine to a state of vibrancy and fluidity, so that it may be the pathway for the ascent of Shakti. During back bending our spine is extended, but as we know by now, in a deep, advanced backbend our trunk extensors need to be released and it is our trunk flexors that open the backbend more deeply. Leg-behind-head postures are the counter postures to backbends. Unless a student is extremely flexible the spine will be in flexion. However the action in the posture is right the opposite. We need to use the back and neck extensors, to return the spine to a neutral or upright position against the weight of the leg being carried behind the head. This makes leg-behind-head postures a more important training for trunk extensor muscles than back bends could ever be.
Apart from trunk and neck extension against resistance the other important supporting action in leg-behind-head postures is the support from the abdominal cavity. Having supported from below with Mula Bandha we now bear downwards with the respiratory diaphragm and inwards with the abdominal muscles. The result is a strong increase in intra-abdominal pressure, which will only protect the low back when all exercises up to this point are performed to a satisfactory level.
Do not attempt leg-behind-head postures if your teacher does not deem you ready. If you are ready and perform these and the later advanced leg-behind-head postures daily, you will develop abdominal muscles as strong as steel. This will ensure that your low back will always be in an excellent condition. The above-described increase in intra-abdominal pressure massages the organs of the abdominal cavity, producing a superb fluid exchange, with stale fluid being expelled under pressure. In this way your organs will be flushed and vitalised.
Apart from the extreme hip rotations, the dynamics between deep back bending and leg-behind-head postures, which performs the core theme of many of the Ashtanga sequences, can easily be called the most important and effective aspect of this asana practice. Since it is the counter- and complimentary theme of back bending, there should be no practice of deep back bends without a competent practice of leg-behind-head postures.
If back bending can be likened to what Freud called the oral phase, then leg-behind-head represents the anal dimension. Freud related saying ‘no’ and defining yourself by setting boundaries with contracting the anus and relating to the father. Typically a child learns not only to wilfully postpone defecation and thus become independent of diapers during the anal phase but also to define itself by saying ‘no’.
While back bending stretches the front of the body (with the oral orifice being located at the front) and increases our ability to say ‘yes’, so strengthens leg-behind-head the back of the body (with the anal orifice located at the back) and improves our ability to say ‘no’. Depending on our level of flexibility, an enormous weight might be placed on our back and shoulders. It will make our back very strong but also increase our ability to shoulder the weight of responsibility. Since we learn to erect our spine tall against resistance, leg-behind-head teaches us to stay unperturbed in the face of corrupting influences. It teaches us also to defend our rightfully held positions in life, if they are under attack. Leg-behind-head generally has a ‘male’, ‘manly’, or heroic influence on our psyche and balances the softening, feminine influence of back bending.
As leg-behind-head forces energy downwards it improves the ‘down breath’, the vital air apana. The psychological dimension ‘anal’, related to saying no, is in yogic terms powered by apana.
Leg-behind-head has an important toning influence also on the pelvic diaphragm, the muscles that form the pelvic floor. This influence is due to pneumatic pressure in the thorax and hydraulic pressure in the abdomen whilst placing ones leg behind ones head combined with the radical external rotation of the femur present in those postures. This theme will be continued later with the extreme hip rotations, which are designed to access the energy reservoir at the base of the spine.
For some students practicing leg-behind-head for 5 breaths per day on each side will not result in the opening desired. The following warm-ups are designed to speed up the opening process in leg-behind-head postures. For maximum effect they may be inserted right before the leg-behind-head sequence. Do this for a limited time only as there is of course a trade off with manipulating the traditional series. This is however still preferable to you desperately cranking your leg behind your head without the necessary opening and hurting yourself in the process. Once you are able to perform the leg-behind-head postures without a warm-up return to the traditional series as quickly as possible. If you cannot perform the warm-ups during your practice you can also do them outside of your practice. You need to take extra care in this case, as you are not at all warmed.
Go into Chaturanga Dandasana, keeping your arms straight and draw your right leg up so that your right knee is under your right shoulder and your right foot approximately under your left shoulder. Please note that your right knee is only about 90 degrees flexed. If you flex it much more and place your foot further down under your chest or hip it will not be an assimilation of a leg-behind-head posture but instead that of a lotus posture, and consequentially will not contribute to your leg-behind-head flexibility. Now lean forward, gently drawing both hips down towards the floor. Make sure that your hips stay square by also drawing the right hip down towards your left foot.
Continue to lean further forward, simultaneously drawing your right shoulder down on your right knee and your left shoulder down on your left foot – ideally until they touch. You don’t need to use strength but instead, allow gravity to draw your chest and torso down to the floor. If you feel discomfort or pain at the lateral aspect (outside) of your right knee, put more emphasis on laterally rotating your right thighbone. Your limitation in leg-behind-head might partially be due to an inability to effectively laterally (externally) rotate your femur. This is often the case on one side only. If you detect this, study more deeply the primary Series postures that require you to laterally rotate your femur, particularly Triang Mukha Ekapada Pashimottanasana and Janushirshasana B on that side where you feel you knee pain.
If you are able to sufficiently laterally rotate your femur you should now be able to feel a significant sensation in your right hip joint. Hold the posture for 5 breaths if done during your vinyasa practice or several minutes if done isolated and then repeat on the left side. Make sure that you keep your hips square at all times being careful to not hold the pelvis in a torqued position.
Lie on your back and draw both feet towards your head, keeping them bent up at approximately 100 degrees. Lift your head and your hips of the floor, engaging your trunk flexors. Take the right foot now, point it and draw it behind your head. Make sure that meanwhile you keep your left foot close to your head. Extending the leg and bringing it into a position resembling the advanced posture Kashyappasana, will at this point of your practice life most likely twist your pelvis. Therefore avoid it.
Exhale, flex your neck and upper thorax more and draw your foot as far down your back as possible. To do this in this posture is much less perilous and strenuous, as you don’t have to keep your spine upright against gravity. In fact, gravity will assist you in getting your leg behind your head. The only thing you need to maintain is tension in your abdominal muscles.
Once your leg is sufficiently behind your neck, extend your neck gently and draw your head down towards the floor. You will feel now that this tends to lift your hips further off the floor. Pointing your foot towards your head, now straighten your left leg completely and draw the left foot towards your chin. Use your back extensors now to straighten your spine, which will draw your hips back down to the floor. You will feel again a significant opening sensation in your right hip joint. The posture is similar to the first warm-up, but much more strength orientated and therefore should be done after the first one. Its great advantage over the first warm-up is that it increases your core strength. Unless you are extremely flexible you need to look at leg-behind-head as core strength training.
This version is only suitable to be done outside of the vinyasa practice. Lie again on your back, bend up your left leg and place the left foot next to your left hip. Make sure you keep you hips level and square. Draw your right foot up towards your forehead. Place a heavy sandbag of say 10 to 15 kg (lbs?) on your right foot. Balance it there to capacity, stabilising it with one or two hands if necessary. If you place a pillow under your head, it becomes a comfortable reading posture. Again feel the opening of the hip joint and breath into it.
You may also gently act as if you were trying to lift the sandbag away from your chest by internally rotating your femur (thigh bone). Do this only to the extent that your effort is overcome by the weight of the sandbag. You will now feel a deeper opening of your hip joint.
This is a modified excerpt from my 2009 text Ashtanga Yoga The Intermediate Series.