Asian Journal of Paleopathology Vol.6, 17–23, 2024
Received: Fubruary 29, 2024
Accepted: March 18, 2024
DOI: 10.32247/ajp2024.6.04

Brief Communication
Prevalent vertebral compression fractures in the lower thoracolumbar spine of the Okhotsk culture human remains from the Moyoro shell mound site, Hokkaido in Japan

Daisuke Kubo, Tomohiro Komagino, Hirofumi Matsumura

Abstract
　The Okhotsk culture was the culture of marine-adapted foragers who inhabited the northern and eastern Hokkaido, Sakhalin, and Kuril Islands during the late first millennium AD. We examined prevalence of the compression fracture in the lower thoracic and lumbar vertebral levels (Th11–L5, and anomalous L6) of the 21 Okhotsk human skeletons from the Moyoro shell mound site, eastern Hokkaido. Compression fracture was found in 11.4% (13/114) of the vertebrae by macroscopic qualitative and quantitative approaches, in which computed tomography was partly utilized. While it was not found in the ten young individuals, about a half of the mature individual skeletons (6/11 or 54.5%) had at least one fractured vertebra. A recent study indicates the possibility that exposure to warm temperature reduces the risk of osteoporosis. Thus, the high prevalence of vertebral compression fractures in the Okhotsk people might be partly attributable to their living in cold environment as well as mechanical stress repetitively caused by maritime activities.

Key words
Vertebral compression fracture, Okhotsk culture, osteoporosis, marine foragers, cold environment.