詳しいガイド（英語）
Meaning and tradition
Shunya is Sanskrit for empty, void or zero, and the gesture is also known as Akash-shamak Mudra, roughly “space-reducing.” It comes from the hasta mudra systems popularized in modern yoga and Ayurveda-influenced hand-gesture manuals and is not a gesture described in classical hatha yoga texts. The Buddhist idea of emptiness (shunyata) is a related philosophical vocabulary, but the finger shape itself is a modern teaching.
By the finger map, thumb is fire, index is air, middle is space, ring is earth, little is water. Folding the middle finger (space) under the thumb (fire) is read in these systems as reducing the space element, and the gesture is grouped with the elemental mudras.
How to practice
Sit in Easy Pose or Lotus Pose, spine tall. Rest the hands palm up on the thighs. Fold each middle finger down until the fingertip reaches the base of the thumb, then lay the thumb over it lightly. The index, ring and little fingers stay extended and loose.
Pair it with Bhramari Breath, the humming bee breath, or with Dirga Breath. Hold 5 to 15 minutes, then release the fingers and shake out the hands.
Tips and common mistakes
Keep the pressure minimal. The thumb is a lid, not a clamp.
Check which finger folds. Unlike Vayu Mudra, where the index is folded, here the index stays straight and the middle is the one folded. Unlike Surya Mudra, where the ring finger folds, here the ring finger stays straight. Unlike Vishnu Mudra, the index and middle are not both folded and the hand does not go to the face; both hands rest on the thighs.
Watch the extended fingers. They should be relaxed and a little apart, not rigid or hyperextended, which can tire the hand quickly.
Keep both hands identical and the palms up. Mixed shapes are a common slip when attention drifts.
Tradition vs. evidence
Traditional claims that this gesture reduces the space element or helps particular ailments are not backed by clinical research. What is defensible is the plain effect of a specific, effortless hand position as a focus anchor, together with whatever calm slow breathing or humming already provide.