Parsvottanasana is a pose rotated half-way between Trikonasana and Parivrtta Trikonasana.   If you remove the Sanskrit sandhi from its name, this pose is "Parsva Uttanasana" -- think of it in that way, as Uttanasana done 90 degrees to the side.

          In this pose, you center your head over your forward leg and you attempt to center your torso there too, although you will never be able to be fully successful.   Still make your maximal effort -- take your torso as much as possible over the midline of your front leg so that your navel comes onto the center your front thigh if possible.   If you are able to do that, then lower your upper abdomen and front ribs to come evenly to both sides of your front thigh, and so on.   This alignment is one of the goals in this pose.

          There are different ways to enter this pose:   (1) you can step back from Uttanasana into the pose, (2) you can step forward from Adho Mukha Svanasana, or (3) you can jump your feet apart from Tadasana and then enter the pose.   The instructions here will be for coming into the pose in this third, classical way.

          Preparation for the pose

          Jump your feet wide into Utthita Hasta Padasana but jump a little less wide than in some of the other standing poses.   Your stance should be less wide than Virabhadrasana II, about the same distance as Parivrtta Trikonasana.   When jumping from Tadasana into Utthita Hasta Padasana specifically for Parsvottanasana (or Virabhadrasana I or III), classically we leave our hands on our hips (not extending them to the chest and out of the sides as with other standing poses) because we intend do other things with our arms in these poses.   Remember -- whenever you have your hands on your hips, try to pull your elbows back to point more toward the wall behind you than to your sides.

          We begin this pose from Utthita Hasta Padasana by raising our hands into Pascimanamaskarasana and then turning to the side because we want to seek symmetry for our hands and arms in a symmetrical leg position before turning our legs into asymmetry.   This is the same reason we raise our arms into Utthita Hastasana before we turn to the side for Virabhadrasana I.

          When you take your hands into the "reverse Namaste" position (which is Anjali mudra done behind your back, known as Pascimanamaskarasana), your entire palms should be pressing together firmly, especially the base knuckles of your forefingers which will have a tendency to bow outward.   Also pay attention to pressing the base of your thumbs together.   Use this hand and arm position to broaden your shoulders and collar bones and help expand your chest.   Press your elbows toward each other to allow you to press your palms together more strongly, and press your little fingers into your back to remind you to press your thoracic spine forward into your chest.   Remember that having your hands in Pascimanamaskarasana is done to open and broaden your chest and help you bring your shoulder blades into your back ribs as you bring your chest forward.   With your hands in this position, you focus on taking your "shoulder bones" (the heads of your humerus bones) back, not on taking your upper arms back.

          As we begin to turn our feet and torso for Parsvottanasana from Utthita Hasta Padasana, there is the tendency not to rotate the rear hip strongly enough forward to bring it in line with the front hip.   It is easy to turn our torso to the side, but hard to turn our pelvis as much to the side as we need.   Establish a strong forward action in your rear hip, combined with a rearward turning of your front hip and buttocks.   Move your rear buttock bone away from your tailbone to assist your pelvis in turning forward.   Turn your rear hip point (anterior superior iliac crest) toward the medial aspect of your front knee.   Move your outer front hip back as you move your outer rear hip forward and your inner rear thigh back.   Press through your feet to accomplish these actions.   Your rear leg buttock must relax to be able to bring your inner thigh back.   Have your pelvis facing 90 degrees to the side, facing directly toward your front leg.

          Before you take your torso forward toward your front leg, as you are turned to the side, take care not to allow your belly just to poke forward.   In fact, draw upward from your abdomen (even upward from your hip points) and establish a backbend in your torso by lifting your sternum toward the ceiling as much as possible.   Lift so much from your sternum that your head begins naturally to tilt back and you raise your chin also toward the ceiling.   As you begin to take your torso forward into the pose, make sure you move from deep within your front hip and try to maintain the back bending flavor you have established as you move more deeply into the pose.

          If your hamstrings are stiff, you may consider bending your front knee as much as is necessary to be faithful to the forward bend, keeping the front of your torso long and your spine extended.   As your hamstrings loosen, slowly straighten your front leg without disturbing any of the other alignments you have achieved in the pose.

          Actions of the torso, hips, and pelvis

          As in all forward bends, in this pose you take your torso forward toward your front leg in two stages: (1) with your back concave as much as possible, maintaining the backbend you established in the preparation for the pose, and then (2) allowing your back to become convex as you take your torso as deeply toward your front leg as you can (but even then striving for a feeling of concavity).

          As you take your torso forward, strive to center your torso over the center of your front thigh.   You want to draw your navel as close to the center of your forward thigh as possible.   Move the ribs on your rear-leg-side forward more strongly toward your front leg than your front ribs in order to help you center your torso over your leg.   Draw your forward hip back so that both sides of your torso are extending equally out of your pelvis.

          Pay particular attention to leveling your hips so they are parallel to the floor.   It is a common mistake to have one hip higher than the other in this pose.   Have your two frontal hips bones absolutely square to the front before you bend forward and keep them like that throughout the pose.   Get someone else to verify this for you since our sensation of where our pelvis is in this pose often betrays us.   One aid you can use is to come onto the heel of your front foot to give you more pelvic mobility while you level your pelvis and then lower your foot back to the floor.   Maintain your pelvis squared to the front (in the direction your front foot is pointing) and leveled from side to side so that it is not tilting in one direction.   Draw your sitting bones up and back and separate them as widely as possible.   Especially pull your front side buttock up away from its thigh and hamstring.

          Next, lengthen both sides of your torso forward from your (level) hips to your armpits away from your pelvis.   This action of the pose is similar to Janu Sirsasana in that our weight tends to want to come away from the forward leg over toward the bent leg.   Try to get your pelvis facing forward and extend both sides of your body evenly over your forward leg from a squared pelvis.   Move your hips and the roots of your thighs back as you move your side ribs forward toward your head.   Keep your shoulder blades moving toward your kidneys as you extend your side ribs further and further away from your hips.

          When you are still in the concave position your head should be up.   The bottom of your sternum should be moving forward and your thoracic ("dorsal") spine should be moving strongly into your body.   The bottom part of your sternum should be moving forward towards your shin.   Look forward, not at the floor but out in front of you while extending over your front leg with your spine concave.   Keep your floating ribs level to the floor.   To level your ribs, your front side floating ribs must move toward the side (meaning toward the rear wall of the room if you began facing the front wall) and your rear side floating ribs must move forward in the direction of your front leg.   Spread your feet wider apart if you can't seem to manage this leveling of your torso.

          Expand your front torso skin toward your chin.   Draw your navel away from your pubic bone and draw your sternum away from your pubic bone to lengthen the front of your torso maximally.   As in all poses, your sternum should have an uplifting feeling to open the front of your torso and your shoulder blades should be drawn into and down your back to assist with this opening.   Press the skin of your back in toward your sternum to help open your chest.

          As you are able, move from the concave position of the spine into the convex position and take your torso deeper toward your front leg.   Keeping the front of your torso long (as opposed to just your "back straight") is always the name of the game, in every asana, especially in Parsvottanasana.   Don't just drop your forehead down to your shin and bend your back to give you a sense that you're going deep into the pose.   Lengthen the front of your torso even while taking your head toward your leg.

          Compact your hips (towards each other) in this pose and be especially aware of this when coming out of the pose to help maintain your balance.

          Actions of the legs and feet

          As in Tadasana, lengthen and broaden the soles of both feet.   Spread all of your toes wide and lengthen them without gripping the floor with them.   Experiment sometimes with lifting your toes (while keeping the balls of your feet on the ground) to extend them more and then placing them back on the floor.   Even though we generally take a shorter stance in this pose than some other standing poses, taking your legs a little farther apart sometimes helps to get more length in your spine.   Experiment with this distance.   Also, the classic heel to arch alignment applies to this pose but with wide hips one may need to use heel to heel alignment so the front hip doesn't cross the rear hip.   If your inner thighs are crisscrossing you need to spread your legs a little more.

          Your rear foot and leg should be turned inward deeply to the point that your feet are almost parallel, more deeply than in any of the other wide-legged standing poses.   Make your rear heel heavy; root it strongly into the floor.   Push energy up from the floor with this foot into your back leg.   Learn to press strongly into the floor with both heels and use that energy to assist the action in your pelvis and torso.

          As in all standing poses, it is especially important to engage your leg muscles strongly to your bones, hugging in from all sides.   Tighten the skin and muscles (quadriceps) of both your thighs to lift your kneecaps toward your groins.   Raise the inside and outside of your knees equally.   Lift the skin on the backs of your thighs and hamstring muscles toward your buttocks.   Especially draw your front leg upward on all sides strongly into your groin.   Although all of your leg muscles are drawing in and upward, have the feeling of lengthening and extending your bones outward toward the floor.

          Press your thighs back (especially the inner thighs of both your legs) as you lengthen your trunk over your front leg.   Experience that balance of opposing actions or forces.   Take the tops of both your thighs strongly back.   Press your thighbones backward as if you want to press them into the backs of your legs.   Draw you rear thigh bone into the back of your leg, drawing back more through the inner aspect of your rear thigh more than through the outer aspect to assist the inward rotation of your rear leg.   Note that both legs are rotating inward in this pose -- both inner thighs are drawing back toward the wall behind you.  As much as you are drawing your thighbones back, draw your sternum more forward.

          Take a moment in the pose to focus on each leg individually and establish its actions clearly.   The front leg in this pose is similar to the legs of Uttanasana and the rear leg is similar to the legs of Adho Mukha Svanasana.   It is easy to let the upper calf area of the front leg "sleep on the floor" -- that is to sag toward the floor without intelligence in that area.   Lift it strongly upward into the shin of your front leg as in Uttanasana.   This is not a problem so much for the rear leg, so focus there more on opening the back of your knee as in Adho Mukha Svanasana.

          Front leg:

          Our weight naturally wants to roll to the outer edge of the front foot, much as it does in Trikonasana, so press the inner edge of your front foot down strongly.   The specific place you want to press down to the floor is your inner heel, right where the front of your heel meets the arch of your foot.   Then, lengthen your toes forward, but be on the medial aspects of your toes.   Often when we feel wobbly or unstable in this pose it is due to not pressing down the forward big toe mound and the inner edge of that front foot.

          Move your front outer hip inward toward the midline as strongly as possible.   So while you are trying to draw your torso more over that front leg, you are also trying to draw that front leg more under the midline of your torso.

          Have your front shin lifting upward toward your knee.   Move your quadriceps muscles up and back, connecting that action all the way down to your inner heel.   Stretch your inner front leg upward toward your pelvis and lift your inner knee up.

          Rear leg:

          Like Virabhadrasana I, your rear leg is inwardly rotating as opposed to Trikonasana, Virabhadrasana II, and Utthita Parsvakonasana.   Draw your rear inner thigh back strongly to facilitate this action.   Move your rear inner knee around the back of that knee toward your outer knee.   And move your rear inner thigh around the back of that thigh toward your outer thigh.

          Don’t bend your back leg.   Open the back of the knee of your rear leg and lift the shin of your rear leg away from the floor.   Make sure your shin goes into your calf (and then secondly, upward toward the knee as you do in your front leg).

          Take your heel down to the floor to open the back of your rear knee.   To enliven your foot and ankle, press the outer edge of your foot down and lift your inner ankle up.   Have the feeling in your rear foot of moving your inner ankle around the front of your foot toward your outer ankle.   This feeling has two effects -- it helps to press the outer edge of that foot down, and also to help lift the inner arch of your rear foot.   But pay attention to the rear skin of that heel which still should move outward and downward.

          Actions of the hands, arms, and shoulders

          In the final position of the asana, if your hands are in Pascimanamaskarasana raise your elbows up toward the ceiling to open and broaden your chest.   Draw your shoulder blades into your back and toward your tailbone to fully extend your spine.   Allow your head and neck to relax and hang naturally with the pull of gravity.

          If Pascimanamaskarasana is too difficult, you can also practice this pose holding your elbows (the Baddha Hasta variation) or holding your wrists (the Baddha Mani Bandha variation), or with your hands on the floor on either side of your front foot.   If you choose this last variation, use your hands to gain leverage in raising your tailbone.

          After you have done your first side of the pose, when transitioning into the second side, if your hands are in Pascimanamaskarasana, see if you can raise your hands a little higher up your back.

          After finishing both sides of the pose, don't shake your hands out if there is pain or tension from holding them in Pascimanamaskarasana, just hold them down to your sides in the Tadasana position and let it subside or do Utthita Hastasana for a moment as a counter-stretch.

          You can try practicing this pose pressing your hands on a wall to feel the action of pressing your hips back.   One way of working is to have your front toes up the wall and the ball of your front foot on the floor.   Then take your hands to the wall and press your hips back and center them side to side so they are level and facing directly to the wall.   Then you can take your hands high up the wall and bend your torso toward the wall and achieve an Adho Mukha Svanasana feeling in your torso.   This is one way to work with the wall.

          Another way to work with the wall is to have your feet a little further from the wall so that you can come into the full concave position of the pose and place your hands on the wall with your arms fully extended and perpendicular to the wall.   Lengthen your torso as much as possible to stretch your hands into the wall, pressing more and more.   Then walk down the wall slowly with your hands, pausing at points to work on stretching your torso toward wall.