Mudras

Mudras

The physical body is made up of five elements namely - Air, Water, Fire, Earth and Aakash (ether - the tiny intercellular spaces in the human body).
Imbalance of these elements disrupts the immunity system and causes disease.
Deficiencies in any of these elements can be made up by connecting one part of the body with another in a particular manner through Mudras. When a finger representing an element is brought into contact with the thumb, that element is brought into balance. Therefore the disease caused by the imbalance is cured. Mudras start electromagnetic currents within the body which balance various constituting elements and restore health. The joining of fingers creates an effect on the human body.
http://www.healthandyoga.com/html/meditation/mudras.aspx 
http://www.inner-light-in.com/2012/05/mudra-origins-power-and-benefits/ 
http://www.yogsadhna.com/index.php?option=com_content&view=article&id=197&Itemid=439 
http://brianprickril.hubpages.com/hub/A-Basic-Guide-to-Hand-Mudras