CCSS, Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea.
Department of Physics, University of Seoul, Seoul, 02504, Korea.
Sci Rep. 2017 Jun 16;7(1):3688. doi: 10.1038/s41598-017-03961-w.
Body-mass index, abbreviated as BMI and given by M/H with the mass M and the height H, has been widely used as a useful proxy to measure a general health status of a human individual. We generalise BMI in the form of M/H and pursue to answer the question of the value of p for populations of animal species including human. We compare values of p for several different datasets for human populations with the ones obtained for other animal populations of fish, whales, and land mammals. All animal populations but humans analyzed in our work are shown to have p ≈ 3 unanimously. In contrast, human populations are different: As young infants grow to become toddlers and keep growing, the sudden change of p is observed at about one year after birth. Infants younger than one year old exhibit significantly larger value of p than two, while children between one and five years old show p ≈ 2, sharply different from other animal species. The observation implies the importance of the upright posture of human individuals. We also propose a simple mechanical model for a human body and suggest that standing and walking upright should put a clear division between bipedal human (p ≈ 2) and other animals (p ≈ 3).
体重指数，缩写为 BMI，由质量 M 和身高 H 给出，已被广泛用作衡量人类个体总体健康状况的有用指标。我们将 BMI 推广为 M/H 的形式，并试图回答包括人类在内的动物物种群体中 p 值的问题。我们将人类的几个不同数据集的 p 值与鱼类、鲸鱼和陆地哺乳动物的其他动物种群的 p 值进行了比较。我们研究的所有动物种群，但人类，都一致显示出 p ≈ 3。相比之下，人类群体则不同：随着婴儿成长为幼儿并继续生长，在出生后大约一年，p 值会发生突然变化。一岁以下的婴儿比两岁的婴儿具有显著更大的 p 值，而一到五岁的儿童则显示出 p ≈ 2，与其他动物物种明显不同。这一观察结果暗示了人类个体直立姿势的重要性。我们还提出了一个人体的简单力学模型，并提出直立和行走的姿势应该将两足行走的人类（p ≈ 2）和其他动物（p ≈ 3）清楚地区分开来。
