We investigated the influence of squatting posture on 343 adult human tali and 227 adult tibiae of the early-modern period from Kumejima, Okinawa, Japan. The prevalence of medial squatting facets (malleolar and trochlear surface extensions) in the Kumejima series was as high as that in recent main-island Japanese. Right medial squatting facets were more frequent than left ones, especially in females. However, we found only lateral squatting facets at the lower end of the tibia in the Kumejima series, while the frequency was quite low, especially in females, among East Asians. This finding corresponded to the low frequency of lateral extension of the trochlear surface of the talus. The prevalence of these facets was significantly higher among males than among females, suggesting that males habitually assumed a squatting position more frequently than females did in the early-modern period. These studies suggested that peoples of the early-modern Kumejima Island did not have as many customs involving a squatting position as the early-modern and modern main-land Japanese.