1. Lineage map — who teaches what, and why it matters for routing

1. Lineage map — who teaches what, and why it matters for routing

An honest yoga skill has to admit that "yoga" means many different things. The same asana name is taught with different alignment cues in different schools, and a teacher trained in one lineage may actively disagree with another.

• Iyengar yoga (B.K.S. Iyengar, Pune, India). Precision, prop use, long holds, staged progression. Poses are taught as craft — alignment is spelled out in fine detail, and props are used to give every body access to the shape. The reference text is Light on Yoga (1966). Teacher training is long and certification is lineage-gated.
• Ashtanga vinyasa (Pattabhi Jois, Mysore, India). A fixed series of postures linked by vinyasa, taught Mysore-style (self-practice under a teacher's eye). Fast, athletic, ujjayi-breath-through-the-whole-practice. The primary, intermediate, and advanced series are prescribed.
• Viniyoga (T.K.V. Desikachar, Chennai, India). Practice adapted to the individual. Sequences are designed for the student in front of you, not for a fixed series. Breath is central and often precedes posture.
• Hatha yoga (broad umbrella). Anything that trains the physical body (asana and pranayama) to prepare for meditation. Most non-lineage "yoga class at a gym" is generic Hatha.
• Restorative yoga (Judith Hanson Lasater, from the Iyengar lineage). Fully supported postures held 5–20 minutes. Deeply parasympathetic. Useful for recovery, stress, and injury.
• Yin yoga (Paul Grilley, building on Paulie Zink's Taoist yoga). Long passive holds (3–5 minutes) targeting fascia and connective tissue. Not the same as restorative.
• Chair yoga (Lakshmi Voelker and others). Yoga adapted for the chair. Appropriate for older adults, mobility-limited practitioners, workplace practice, and rehab.
• Bikram / hot yoga (Bikram Choudhury). A fixed 26-posture sequence in a heated room. This lineage has a well-documented history of abuse by its founder; mention it for completeness and for context about a user's history, but do not recommend new practice in it.

A routing agent must ask or infer which lineage the user is already inside before prescribing. Giving an Ashtanga student Iyengar-length holds, or giving an Iyengar student Ashtanga-speed vinyasa, is a category error.

2. Asana families — the organizing structure

The Iyengar school groups asanas into families because the alignment principles within a family transfer across poses. A routing agent that understands the families can generate useful home practice even without memorizing every pose.

2.1 Standing poses

Tadasana (mountain), utthita trikonasana (extended triangle), virabhadrasana I, II, III (warrior 1, 2, 3), parsvakonasana (extended side angle), parsvottanasana (intense side stretch), utkatasana (chair), vrksasana (tree). The standing poses are where Iyengar students live for their first year. They train the legs and the pelvis to support everything else.

Alignment principles for the standing-pose family:

• The outer edges of both feet are parallel to the mat edge, or turned in the prescribed way for the pose. The weight is distributed to four corners of each foot.
• The kneecaps track over the second and third toes. A knee that collapses inward is a routing flag — stop and correct before progressing.
• The quadriceps lift the kneecaps. This locks the knee safely.
• The tailbone lengthens down. The lower ribs draw back toward the spine.
• The crown of the head lifts away from the pelvis.

2.2 Seated poses

Dandasana (staff), paschimottanasana (seated forward fold), janu sirsasana (head-to-knee), baddha konasana (bound angle), upavistha konasana (wide seated angle), virasana (hero), sukhasana (easy). Seated poses are where hamstring and hip-joint tightness produces the most misalignment. Use props aggressively — a folded blanket under the sit-bones, a strap around the feet, a block between the knees.

2.3 Forward folds

Uttanasana (standing forward fold), prasarita padottanasana (wide-legged forward fold), paschimottanasana (seated). The Iyengar cue "fold from the hip joint, not the waist" is the key. Fold from the hip joint with a flat back as far as possible, then allow any rounding. Rounding from the waist is how backs get hurt.

2.4 Backbends

Urdhva mukha svanasana (upward-facing dog), bhujangasana (cobra), setu bandha sarvangasana (bridge), urdhva dhanurasana (wheel), ustrasana (camel). The backbend family is high-reward and high-risk. Key cue: lengthen the spine before arching it. The lumbar is where most backbend injuries happen; protect it by engaging the legs and drawing the pubis forward.

2.5 Twists

Ardha matsyendrasana, marichyasana, parivrtta trikonasana, parivrtta parsvakonasana, bharadvajasana. Twists are sequenced before backbends in Iyengar sequences because they release the spine. Key cue: lengthen the spine on the inhale, twist on the exhale. Never force a twist — the depth should come from the exhale.

2.6 Inversions

Salamba sirsasana (headstand), salamba sarvangasana (shoulderstand), halasana (plow), viparita karani (legs-up-wall). Inversions are the most famous Iyengar poses and the most safety-sensitive. Headstand and shoulderstand require dedicated preparation, usually a year or more of foundational work in the other families before they are introduced.

2.7 Arm balances

Bakasana (crow), chaturanga dandasana, pincha mayurasana (forearm balance), adho mukha vrksasana (handstand). Arm balances are a small family in the Iyengar method and a large one in Ashtanga. They come after the standing-pose foundation.

2.8 Recuperative / restorative

Savasana (corpse), supta baddha konasana (reclined bound angle), setu bandha sarvangasana with a bolster. Every full practice closes with savasana, minimum 5 minutes.

3. The prop toolbox

Iyengar's lasting contribution to world yoga is the prop. Props do not make a practice "easier" — they make the alignment accessible so the practitioner can feel the correct shape. Then the prop is gradually removed.

Heuristic for prop use: if a pose is inaccessible without a prop, it stays with the prop. If a pose is accessible with a prop but the shape is wrong without it, it stays with the prop. The prop comes out when the shape holds independently.

4. Alignment — ten rules

These are the ten rules an Iyengar teacher would return to again and again. A routing agent with this skill loaded should check proposed postures against these rules before giving the instruction.

1. Feet first. The feet set the foundation for every standing pose. Correct the feet before correcting anything above.
2. Knees track the toes. A knee that rolls in is a structural failure. Stop, re-engage the legs, try again.
3. Lengthen before you move. Spinal extension precedes twisting, bending, or folding.
4. Fold from the hip joint, not the waist. In any forward fold, preserve the length of the lumbar spine.
5. The back of the neck is long. In every seated and supine pose, the chin tucks slightly so the cervical curve is not compressed.
6. Shoulders down and back. Not pinched — just moved away from the ears, down the back, and open at the front.
7. Breath is the metronome. If the breath goes ragged, the pose is too hard. Back off.
8. Use props early, not late. Props come in before the pose breaks down, not after.
9. Never lock a joint at the end of range. The knee, the elbow, and the wrist are all protected by muscular engagement, not by ligamentous end-range.
10. Come out with the same care you went in with. Most injuries happen on the exit. Unwind a backbend slowly. Drop the legs out of shoulderstand slowly.

5. Sequencing — the staircase logic

Iyengar sequences are not random. A well-sequenced practice starts where the body is cold and ends in savasana, and it moves through the families in an order that prepares the later poses with the earlier ones.

A generic 60-minute Iyengar sequence:

1. Opening: 3–5 minutes in supta baddha konasana or savasana with breath awareness.
2. Warm-up: dynamic cat-cow, adho mukha svanasana (downward dog), tadasana.
3. Standing pose block (20 minutes): trikonasana, parsvakonasana, virabhadrasana II, parsvottanasana, prasarita padottanasana.
4. Seated forward fold block (10 minutes): dandasana, janu sirsasana, paschimottanasana.
5. Twist block (8 minutes): bharadvajasana, ardha matsyendrasana.
6. Backbend block (5–10 minutes): setu bandha sarvangasana with a block, ustrasana.
7. Inversion (5–10 minutes): sarvangasana with a chair or blanket, halasana.
8. Savasana: 8–10 minutes.

Sequencing rule: inversions come after backbends, backbends come after twists, twists come after seated work, seated work comes after standing work. Savasana is always last.

6. Worked examples

6.1 Utthita trikonasana — extended triangle

Setup. From tadasana, step the feet 3.5 to 4 feet apart. The right foot turns out 90 degrees, the left foot turns in slightly. Align the right heel with the arch of the left foot. Arms extend parallel to the floor, palms down.

Entry. Inhale, lift the spine. Exhale, extend the right arm forward as far as it will go without collapsing the torso, then tip the pelvis to the right and hinge from the hip joint. The right hand lands on the shin, a block, or the floor outside the right foot. The left arm extends straight up. Gaze up at the left thumb (or down if neck is an issue).

Alignment check. Both legs straight. Right knee tracking the second toe. Left hip stacked over the right hip as much as possible — this is the place triangle is most often wrong; the top hip collapses forward. Spine long; do not curl the torso toward the floor. Shoulders down. Both sides of the waist equally long.

Failure mode. Bending the right knee. Collapsing the torso toward the shin. Reaching the right hand below the range that the spine can follow. Correction: use a block under the right hand. A block is not a consolation prize.

6.2 Setu bandha sarvangasana — supported bridge

Setup. Lie supine. Feet flat, knees bent, heels close to the sit-bones. A block is placed lengthwise under the sacrum — not the lumbar spine, the sacrum, which is the flat triangular bone at the base of the spine.

Entry. Press the feet, lift the pelvis, slide the block under the sacrum. Let the sacrum rest on the block. The chest opens, the shoulders settle on the floor.

Alignment check. The block is on its lowest setting for a beginner, medium setting for intermediate. The lumbar spine should not feel compressed. If it does, lower the block or remove it.

Duration. 3–8 minutes. This is a restorative pose masquerading as a backbend.

Failure mode. Block too high for the practitioner → lumbar compression → low back ache the next day. Correction: a lower block or a folded blanket instead.

7. Routing heuristics

8. Safety failure modes — the injury list

Yoga injuries are real and well-documented. The most common categories:

1. Lower back. Forward-folding from the waist instead of the hip joint. Overdoing backbends without preparation. Correction: fold from the hip; prepare backbends with psoas-lengthening and upper-back-opening work; do not compete.
2. Knees. Forcing lotus or half-lotus when the hip is not ready; letting the knee roll inward in standing poses; hyperextending in forward folds. Correction: never force hip-opening through the knee; use blocks and blankets; engage the quadriceps.
3. Neck. Pressing weight into the head in headstand and shoulderstand without trained preparation. This is how people cause cervical disc injury. Shoulderstand requires a folded blanket under the shoulders so the cervical curve is preserved. Headstand is not a beginner pose.
4. Wrists. Chaturanga and arm balances with insufficient shoulder and core strength. Correction: build strength with block-assisted chaturanga and wall work before full expression.
5. Shoulders. Aggressive chaturanga pattern, over-gripping in down dog, collapsing in handstand. Correction: external rotation of the upper arm, engagement of the serratus anterior.
6. Stroke and vascular events. Rare but documented in extreme neck-rotation poses and aggressive headstand practice. This is why headstand is taught late, with preparation, and not at all to anyone with vascular risk factors.

Hard rules:

• No headstand without a trained teacher and dedicated preparation.
• No shoulderstand without a folded blanket under the shoulders.
• No hot yoga in pregnancy or with cardiovascular disease.
• No deep twists or backbends in pregnancy without a prenatal-trained teacher.
• No forcing. The Sanskrit word is "sthira sukham asanam" — steady and comfortable seat. If it is not comfortable, it is not the pose.

9. Concept index

• mind-body-asana-families
• mind-body-alignment-principles
• mind-body-prop-use
• mind-body-yoga-sequencing
• mind-body-yoga-safety
• mind-body-lineage-map