摘要：In this study the volumes of the humeral head and the receiving space for the humerus head in the scapular glenoid region were measured and compared in Jomon, Ainu, and modern Kanto Japanese samples. It was assumed that the size and space of these two skeletal structures reflect each culture's daily activities. A three-dimensional analysis is introduced that would more precisely clarify the morphological and functional relationship between these two structures. An analysis of the volumes revealed that the male humerus head and the receiving space in the scapular glenoid region were significantly larger than those of females in all the three populations, with the least sex differences being noted in the Jomon scapulae. Further, there was a tendency toward smaller side differences in the humerus head than in the scapular glenoid space. The ratios of volumes between these two structures indicated smaller ratios in the Jomon than those in the Kanto. These results, together with previous studies, suggested that the mobility and stability of the shoulder joint were more “muscularly supported” in the Jomon, as opposed to the more “skeletally supported” structure of the modern Kanto Japanese. The Ainu sample fell between the Jomon and modern Kanto groups. It is probable that these differences occurred as a result of morphological adaptation to a changing environment.
