Brad's Iyengar Yoga Notebook
"If you do not know Tadasana, you do not know Sirsasana at all,
though you can stand on your head."   -- B.K.S. Iyengar
Sirsasana is nothing but Tadasana on your head.   The actions in the pose are essentially the same, though they feel different to you when you are doing them upside-down.   As you work in the pose, try to feel as though you are standing in Tadasana.   With repeated practice, this pose fosters equanimity.
You can hold this pose for up to 30-45 minutes, but do not exceed that time as a general practice.   For most students, a 7 to 10 minute Sirsasana is a good goal.   You need to be able to hold the straight pose for at least about 5 minutes before you are ready to begin working on any of the leg variations.
All inverted poses including Adho Mukha Svanasana constitute weight training for your diaphragm since your abdominal contents will rest down on your diaphragm in the inverted position and you must breathe against their weight.
It is essentially mandatory to follow Sirsasana at some point in your session with Sarvangasana or Setu Bandha Sarvangasana for the re-extension these poses give to the cervical spine as well as the calming effect they have on the brain.   In Sirsasana, your head is straight with your torso allowing the energy or fire of your body to go into your head and create a stimulation.   Later in the session, you use Sarvangasana or Setu Bandha Sarvangasana, which employs Jalandhara Bandha, to keep the energy out of your head and to relax and cool the brain.   Sirsasana is a little more of a heating pose, and Sarvangasana is a little more cooling.
To set up for Sirsasana, you may use a single blanket in the "storage fold" placed on a sticky mat, or you can "double fold" your sticky mat into quarters for padding.   You can also place your head right on the floor, though that may be uncomfortable for you.   Whatever you use, do not have your Sirsasana padding to high (for instance two blankets in storage fold).   That is like trying to do Tadasana on a water bed -- it just does not provide enough support for good balance.
Most beginners practice the pose first with their backs to a wall.   Fearful students can even practice in a corner rather than at the wall as it gives them more security.   If you are using a wall, it is good to begin with your hands very close to the wall, even placing your knuckles on the wall.   In Light on Yoga, Mr. Iyengar shows the wall version of this pose with his hands away from the wall, but he later changed that instruction to take the knuckles of the hands right up against the wall if you are doing the pose at the wall.   If you are using a blanket, have the rounded edge of the blanket touch the wall.
If you use the wall, do not rest your buttocks on the wall.   Not only is this lazy, it places strain on your neck.   Place your heels on the wall and "scrub" them upward along the wall to try to take your torso and legs higher and higher.   A good beginner's way to come into and out of this pose (especially at the wall) is to come up and down one leg at a time with each leg completely straight.   Once you are able to balance in the center of the room, when entering Sirsasana, strive to learn to lift both of your legs slowly, evenly, straight, and together into the pose and to come out of the pose the same way.   Going up into the pose with straight legs held together takes time, along with hip and hamstring flexibility.   Since it is easier, first learn to come down slowly and gently with straight legs, then practice going up into the pose the same way by learning to walk your feet in toward your head further and further until they can lift off the floor.   When walking in with your feet to go up into the pose with your legs together, you must take your thoracic spine inward and allow your hips to move back behind you to counterbalance the weight of your legs.
You should remove your glasses for this and all inversions.   As you place your arms to come into Sirsasana, place your elbows shoulder width apart and have them directly under your shoulders.   Keep your elbows facing forward toward the front of the room -- your elbows should not splay outward very much.   Adjust your elbows so your outer shoulders and outer elbows are on the same line.   In other words, have your elbows in line with your outer armpits.   The center line of your triceps should face directly back toward the wall you are facing.   Look at photos of Mr. Iyengar to see his elbow positioning.
As you are placing your arms on your support, move your forearm flesh inward on your mat or blanket so you press your ulna into your support.   Interlace your fingers all the way up to the webbing and keep them there, but do not grip them very tightly -- you will want to relax your hands while you hold the pose.   Remember to alternate the interlacing of your fingers so that you are not doing the same side all the time, just as you alternate which leg is on top in Padmasana.   When you place your hands down, have your upper wrist bones directly over your lower wrist bones and maintain that alignment throughout the pose; don't let your wrists roll outward as is common.   Often this means focusing on maintaining the contact of the webbing of your forefingers, since this area can slip apart easily when you are in the pose.
As you interlace your fingers, the thumbs should be touching in about 99% of people.   Very few people have heads that are so large that their thumbs cannot touch when the back of their heads are placed into their hands.   Keep the tips of your thumbs joined together, or perhaps overlapping if your anatomy permits that.   The next step is to lengthen the underside of your forearms where they touch the mat or support.   Move your little fingers ("pinkies") further away from your torso along the mat so that your hands are vertical.   You can also pick up each elbow and move it back toward your torso to help lengthen the undersurface of your forearm.
Some teachers teach to take the bottom-most little finger inside the little finger just above it so it does not get crushed under the weight of the hands.   In this position, the lower little finger rests along the lower palm of the opposite hand (along the hypothenar eminence).   This is not a standard instruction, however.
Next place the back of your head into your hands.   You should be on your head at a point midway between your forehead and the crown of your head (its highest point when standing).   Your head does not go all the way into the curves of your fingers.   Mr. Iyengar teaches that the rear part of the head touches the palms and the base or heels of the palms -- it does not touch the little finger sides of your palms.
Remember to keep length at the base of your posterior head and neck area.   The bottom rear portion of your skull should have a downward intention.
Relax your face and eyes in Sirsasana.   One way of doing this while in the pose is to look more upward on the wall across the room from you (that is, you are gazing more downward with reference to your face).
Actions of the hands, arms, and shoulders
Once you have come into the pose, remember to relax your fingers in the pose, but keep them interlaced up to the webbing.   Learn to relax your hands while holding their position intact, as if there were no more effort in them than when resting them on your lap.   Your hands do not press down on the mat like your elbows, forearms, and wrists do.   But do press your lower wrist bones into the mat as strongly as your elbows and forearms.
Once you are in Sirsasana, one of the actions you will have to focus on is raising your shoulders and shoulder blades strongly toward the ceiling.   When you're upside-down, gravity pulls your shoulders down toward your ears so you need to raise them away from your ears, as opposed to Tadasana and other right-side-up poses when you are usually lowering your shoulders away from your ears.   Similarly, you need to lift your shoulder blades (scapulae) toward your hips in the inverted poses, as opposed to the standing poses where you are drawing them downward.   Still, the principle is always the same -- ears moving away from the shoulders, shoulder blades moving into and down the back toward the rear pelvis.   One important action to establish from the beginning is the pressing of your forearms down on the mat for the purpose of lifting your shoulders.   You should feel that connection strongly.   Also allow this forearm pressing to help you lift your upper inner arms away from the floor, raising your biceps away from the floor and drawing your triceps toward the floor.   In this action, pull your shoulders away from the wall behind you.
Much as you sometimes have to keep "recharging" your kneecaps and leg muscles in the standing poses, drawing them up as they fall, you may have to keep "recharging" your shoulders and shoulderblades toward the ceiling in Sirsasana.   Imagine that you have little skewers under your shoulders in Sirsasana that jab you just a little each time you let your shoulders drop, reminding you to lift them.   When you can no longer lift your shoulders due to tiredness, it's time to come out of the pose because not lifting your shoulders puts too much weight into your cervical spine.
Initially the above actions of pressing your arms into the floor to raise your shoulders and shoulderblades is important to learn.   Once you have integrated that action, and learned what it has to teach about lifting your shoulders and upper arms, you should aim for relaxing the effort in your arms as much as possible while still keeping your shoulders lifting strongly.   This is "head balance," not "forearm balance."   Over time, you should move toward carrying your weight on your head, though this must be built up to gradually and safely and not rushed into from the beginning of your practice of Sirsasana.
Broaden your shoulders as you lift them.   Broaden your shoulder blades and bring them forward to press into the back of your body.   Raise your trapezius muscles.   Broaden your collarbones.   Keep your neck long.   Do not be on your elbows -- be more in the back of your body, on your head, almost with a feeling of falling over backwards (but don't).
Actions of the torso, hips, and pelvis
The first action of your torso (and whole body in general) should be one of lengthening your spine and your entire body maximally from your head upward all the way up through your heels and the balls of your feet.   Raise even from your armpits.   Lift and lengthen the sides of your chest and torso.   Can you lengthen your side ribs here by pressing your arms down as if to get the feeling of doing Urdhva Hastasana in this pose?   Also lift your lower front ribs upward toward the ceiling and lift your tailbone and the backs of your thighs to balance that action.   Also lift your back ribs toward the ceiling.   Lift your pubic bone away from your sternum.   In short, lift your whole pelvis upward as much as possible, taking its weight off your torso, and allowing you to lengthen your spine maximally.   Lift your outer hips upward and do asvini mudra (tightening and lifting your anus) so you're lifting your pelvis both from the inner and the outer aspects.
Next, focus on keeping your torso in straight alignment as much as possible.   Unlike Sarvangasana, in Sirsasana the common mistake is for the front of the body and spine to overstretch.   The tendency is to push the front ribs forward and collapse the lumbar spine, letting the buttocks poke out in the back causing the so-called "banana back."   A similar common mistake at the wall is to rest in the pose by arching back, resting the buttocks or legs on the wall and hyperextending the spine.   If you are using a wall, try to minimize its use.
Keep your hips directly over your shoulders.   Minimize the arch in your low back, though it will always be there somewhat.   Your lumbar spine should be slightly concave (normal lordosis) but tuck your tailbone inward and lift it toward the ceiling (which is just a Tadasana action upside-down).   Don't let your buttocks drop or sag.   Tighten your buttocks gently as you do this but do not push groins forward (there should be a hip crease in this pose).   Let your groins recede so they "hollow."   One way to check on this is that there should be some wrinkles in the front of your shorts -- they should not be stretched taught there.   Draw your navel in toward your spine by using your spine, not your abdominal muscles.   Pay attention if your lower ribs are coming forward and take your abdomen back toward the wall behind you and your buttocks upward toward the ceiling.
Also focus on your thoracic (or "dorsal") spine.   Take your thoracic spine into your body and upward.   The thoracic region should never come back.   Suck your thoracic spine into your body.   But at the same time you are pressing your thoracic spine forward, open the skin of your thoracic back.   This is a key point.   Focus more and more on bringing your thoracic spine inward and taking your front ribs back to reduce the "banana back."   The only way you are going to achieve this and not fall is to lift more and more strongly through your inner legs, another key point.
Bring the anal mouth up to the level of your perineum by lifting your sacrum.   In both Sirsasana and also Sarvangasana, imagine that you have a vertical pole running from your perineum to the ceiling.   Grasp that pole with your inner legs and pull it upward and tuck your sacrum in toward the pole.   Lift your perineum higher and higher and bring your thighs closer without gripping your buttocks.
Actions of the legs and feet
The most important actions in this pose are lifting your shoulders (trapezius muscles) and lifting your legs higher and higher.
When we are upside-down, there is a tendency to lose the consciousness or intelligence of the legs since they are no longer supporting the weight of the body.   Observe the Tadasana of the legs and give them strong focus upward toward the ceiling.   Pay attention to lifting your legs out of your pelvis toward the ceiling as much as possible and engaging your leg muscles to the bones just as consciously as you do in the standing asanas.   Squeeze your muscles into your legs and up toward the ceiling.   Keep your legs active by squeezing your outer legs (thighs, knees, calves, and ankles) in toward each other to help maximize lifting them toward the ceiling.
Draw your thigh bones deep into the backs of your legs as in the standing poses.   Take your front thigh muscles into your thigh bones and your thigh bones back into your hamstrings.   Draw your inner thighs back more than your outer thighs to rotate your thighs inward slightly so that they face directly forward as in Tadasana.   Keep rolling your outer thighs inward, even if it is tiring.   Tuck your tailbone in as you move your thighbones backward to keep your legs centered and moving straight up out of your pelvis.   Draw your kneecaps into your legs and down toward your pelvis.
Stretch the backs of your legs well.   Open the backs of your knees well.   Your kneecap has to go into your knee and the back of your knee has to open.   Then elongate your calf muscles toward your heels.
Reach upward through the insides of your feet and legs more than the outsides.   Lift upward through your inner ankles.   Draw the inner and back skin of your legs upward while you draw the outer and front skin of your legs (especially your thighs) downward into your hips.   Extend upward through your inner heels and your inner legs.   Lift from your inner knees upward through your inner ankles, and especially from your inner ankles upward through your inner heels.
Extend upward both through your heels and also through the balls of your feet (especially at the great toes), pushing the balls of your feet upward slightly as though you are stepping on the gas of your car.   Lengthen and broaden the soles of your feet as in Tadasana so the skin of your soles is stretching.   Lengthen the front of your feet.   Broaden the balls of your feet from the inside outward.   Spread your toes and pull them back slightly.   Your inner ankle bones move toward each other -- try to touch them together as in Tadasana.
Keep your legs lifting strongly out of your pelvis throughout the pose.   Lift upward through your legs and feet over and over again, recharging them as often as necessary.   This will also help lead you to correct your thoracic region from moving back.
Do not overwork in this pose -- try to use more skill, balance, and relaxation than effort.   Generally we do not repeat Sirsasana once we have come down out of the pose.   If you lose your strength, (for example to keep your shoulders lifted), come down and stay down.   If you only lose your balance, you can go back up and continue to practice.
Sirsasana is one of the poses that lends itself to practicing in front of a mirror occasionally since you can often see poor alignments in that way that you cannot always feel.
After Sirsasana, if you do the pose on a mat, take a look at the indentations in the sticky mat and use that information to verify that your posture was correct or to learn more about your posture and where your weight was distributed.
After an extended Sirsasana, it is good to do a pose to release the back of your neck, like Pascimottanasana looking upward or standing Padangusthasana looking upward with a concave spine (use a belt around your feet if necessary) -- this is a sort of "backbend in a forward bend" and helps relieve some of the stresses of Sirsasana.