Umadashi Matsuri (Horse Carriage Festival) is an event typically held during Japanese Fall festivals.http://nirc.nanzan-u.ac.jp/publications/afs/pdf/a131.pdf Page 34 A dashi is a carriage in which the spirit of a god rides in ritual procession. In Umadashi Matsuri, the horse (uma) substitutes the carriage. Young people grab onto the reins of horses and run through the sand with them.
References
External links Azuma Shrine, Umadashi Festival , Japan National Tourism Organization