詳しいガイド（英語）
Meaning and tradition
Shankha is the Sanskrit word for the conch shell, which is blown in Hindu temples and ceremonies, and is carried by Vishnu as one of his sacred emblems. The name of the mudra, sometimes spelled Shankha, comes from this shell. It is a popular, modern hand-gesture practice, taught in many yoga and mudra guides, rather than a gesture from a classical hatha yoga text. Because both hands are involved together, it is described as balancing all five elements. Tradition associates the conch with sound and the voice, and so the mudra is often paired with chanting.
How to practice
Sit in Easy Pose, or in Lotus Pose if it is comfortable for you. Extend the left hand with the thumb up and the fingers together, turn it toward the body, and wrap the four fingers of the right hand around the left thumb. Touch the right thumb tip to the tip of the left middle finger. Hold the joined hands at the chest. Breathe with Om Breath, chanting Om on the exhale, or with Ujjayi Breath. Hold for 5 to 15 minutes, then release the right hand and shake out both hands.
Tips and common mistakes
The shape is closed, like a shell. The right fingers wrap around the left thumb, and the right thumb meets the left middle fingertip.
Unlike Linga Mudra, where the fingers of both hands are interlocked and the left thumb stands up free, encircled only by the right thumb and index finger, here the right fingers wrap around the left thumb and nothing is interlaced.
Unlike Garuda Mudra, where the wrists cross, the thumbs interlock, and the fingers spread wide like wings, here the hands are closed together into a compact shape and the fingers do not spread.
Keep the left fingers extended rather than curled, so the shell outline remains clear. Keep the grip soft and the shoulders down. Do not let the elbows lift or the hands drift to the throat.
Tradition vs. evidence
Mudras have little clinical research behind them, and none supports claims about voice or elemental balance from this one. What is defensible is that a closed, held hand shape is a clear attention anchor, and that pairing it with a hum or Om gives the hands and voice a shared task. The conch symbolism is traditional.