In 1911, German internist and anthropologist Erwin von Bälz (1849–1913) talked about the people from Ryūkyū, in whose “peculiarities” he was interested: “When I learned in 1899 that recruits from Riu-Kiu [sic] had been recruited in the southern garrisons, I asked the military authorities for permission, which they gladly granted, to study these people anthropologically. In this I was most gratefully assisted by the military physicians, most of whom were my students.” After his military training (1890–1892), Yabu Kentsū 屋部憲通 (1866–1937) was also stationed in southern Japan. Since universal conscription had been introduced there in 1898, however, he had been jointly responsible for the first three military drafts in Okinawa. Although Bälz and Yabu certainly have never met, it may have been the young Okinawan military recruits drafted by Yabu and who were later examined by Bälz.
Sources:
Korrespondenz-Blatt der Deutschen Gesellschaft für Anthropologie (1911), page 188
Investigations into the history of karate 