This cow crupper originates from the Tōhoku region during Japan’s Edo period (1603–1868), where cattle played an essential role in agriculture and transport, especially in mountainous northern terrain. Designed to secure packs and harnesses, the crupper fit beneath the animal’s tail, preventing loads from slipping forward on steep paths.

A similar example can be seen in Tokyo’s Mingeikan (folk craft museum).

Japan
Deer bone, rope
37 ½ inches length. 10 inches of beaded bones on either side, maximum bone width of 3 ¾ inches. 

Edo Period (1600-1868)