The sumo pre-bout ritual of repeated crouching and rising is called shikiri.
During shikiri, wrestlers face each other, crouch at the starting lines, rise, and repeat the preparation before the tachiai. They may also stamp their feet, clap, extend their arms, and throw salt into the ring as part of the wider ceremonial sequence.
The routine gives wrestlers time to focus and prepare mentally while preserving the formal rhythm of the contest. In top-division bouts, the visible preparation can last several minutes even though the actual clash often lasts only seconds.
Shikiri is sometimes incorrectly used as a synonym for the tachiai. The distinction is important: shikiri is the preparation, while tachiai is the opening collision that begins the bout.