Uddhiyana bandha

literally, the "flying up lock", being the abdominal lock. In practice, the diaphragm and all the abdominal organs beneath it, clear down to the sexual organs, are lifted, so that they "fly up" towards the thoracic cavity. This is one of a number of such muscular contractions (see bandha, and mudra) used to control the internal breath. See also agnisara dhauti.