In short: butterfly is the yin yoga version of a soles-together seated fold. You sit, bring the soles of the feet together, slide the feet well away from you and let the back round forward over the legs, then stay still for several minutes with the muscles relaxed. It is often the first pose of a yin class.
This page explains how the yin butterfly differs from the active bound angle pose, how to set it up with props, what to do during the long hold and how to come out.
The name and the related asana
Butterfly is an English yin name, with no Sanskrit of its own. It looks like bound angle pose (Baddha Koṇāsana), but the instructions and the intention differ. In bound angle the heels are drawn close to the pelvis and the spine stays long and lifted; in yin butterfly, as Bernie Clark and Sarah Powers teach it, the feet slide away from the body, the back is allowed to round, and the muscles stay soft so the stretch can settle into the deeper tissues over time. Clark notes that moving the feet farther away shifts the stretch toward the back and hamstrings, while closer feet stretch the inner thighs more.
Setting up with props
Sit on a cushion or the edge of a folded blanket so the pelvis can tip forward; Sarah Powers suggests shifting onto the front edge of the sitting bones. With sciatica, Clark advises raising the hips until the knees are lower than the hips, or skipping the pose. A bolster across the feet or thighs gives the chest or head somewhere to rest, and Yoga Journal shows a cushion on the feet as a head rest. If the neck does not like hanging, cup the head in the hands with the elbows on the feet or the floor.
Common habits to unlearn
People who come to yin from active styles often pull the heels in tight to the groin out of habit. Bernie Clark encourages them to move the feet away so the legs form a wide diamond. With the feet close, tight inner thighs or a stiff lower back can stop you folding at all; with the feet farther away, butterfly becomes one of the easiest ways to stretch the lower back without needing loose hamstrings.
Watch the pelvis too. If it rolls backward as you sit, the fold happens only in the upper back. Sit higher on a cushion until the pelvis can tip forward. The arms are free: hold the feet, rest the hands on the floor in front of you or let the arms relax behind you. Clark also notes that the pose can be done after a meal as long as the head does not press down onto the floor, and that the wide legs leave room for the belly, which is why it is often offered in pregnancy.
The long hold
Fold until you meet the first clear resistance, then stop and let the body be still. That is the core yin instruction: come to an edge, keep the muscles relaxed and stay. Both Clark and Powers suggest three to five minutes, longer as you get used to it. If the sensation grows sharp, back off; if it fades, you may fold a little further. Our diaphragmatic breathing guide is a good companion for the stillness.
Coming out and the rebound
After a long hold, come out slowly. Push the floor away with the hands and roll up, lean back on the hands to release the hips, then straighten one leg at a time. Pause for a few breaths with the legs long: many yin teachers call this pause the rebound. Clark suggests gentle counterposes such as a seated backbend, lying on the belly, tabletop or a seated twist.
Precautions in plain words
The main cautions are for the back and the sciatic nerve. With sciatica, raise the hips or skip the pose. If your lower back should not round, use the reclining version: lie on your back with the legs in the same diamond shape. With a neck injury, support the head rather than letting it drop. In pregnancy keep the fold small. This page is general information, not individual advice.
Before, after and where it is taught
Butterfly often opens a yin class or follows caterpillar; half butterfly and dragonfly are natural next steps, and reclining bound angle is the restful, lying-down cousin. You will meet it in yin yoga classes, which hold mostly floor poses for several minutes with the muscles relaxed, and in some gentle and restorative classes.
