Monkey Performance : The Development of Bipedalism in Trained Monkeys

日本猴子表演协会(Suo-Sarumawashi)合作的一系列研究揭示了日本猴子两足行走的潜力。以稳定直立姿势为目标的长期训练导致猴子腰椎前凸明显。这一特征不仅在形态上，而且在功能上都与人类的情况相当。即使在正常的前卧位下，猴子也能保持发达的前凸。颅后骨骼的骨重建也证明了对持续的两足行走所产生的压力的功能性适应。受过训练的猴子的后颅骨显示出高度增强的骨骼结构强度和相对较大的关节尺寸。尽管有这样的适应，但后肢骨骼的修改与人类的情况相当不同。这表明了功能必要性和基因决定的解剖学之间的妥协。与脊柱相比，日本猴的后肢在许多方面似乎更适合四足运动。

A series of studies collaborated by the Suo-sarumawashi (Japanese Monkey Performance) revealed the potential for bipedalism in Japanese monkey. The long-term training which aimed at stable upright posture introduced marked lumbar lordosis in monkeys. This feature is comparable to the humans' condition not only morphologically, but also functionally. The developed lordosis was retained even in normal pronograde posture of the monkeys. Bone remodeling in the postcranial skeleton also evidenced functional adaptations for stresses induced by sustained bipedalism. Postcrania of a trained monkey showed highly increased structural strength of bones and relatively large articular dimensions. Despite such adaptations, modifications of hindlimb bones were rather distinctive from humans' condition. This indicates a compromise between functional necessity and genetically determined anatomy. The hindlimb of Japanese monkey seemed to be more specialized for quadrupedal locomotion in many aspects compared to the vertebral column.