Jnana Mudra and Chin Mudra
The Jnana mudra (fingers pointing up) and Chin mudra (fingers pointing down) are the two best known mudras of hatha yoga and have an effect on a mental, emotional, physical and spiritual level. The closed circle of thumb and index finger represents the goal of yoga, the union between human and world consciousness.
Place the tip of the thumb on the index fingertip and extend the other fingers. Alternatively, touch the first joint of thumb with the index fingertip allowing the thumb to lightly press against the index finger nail. Do this with either hand or both at the same time. The hand is generally placed in a relaxed position on the thigh or held in front of the heart.
This mudra activates the metal element, and its associated color white, bringing peace of mind, knowledge and wisdom. It helps reduce mental stress and promotes concentration and memory. Physically it is used for insomnia or lethargy and depression and may reduce high blood pressure.