Abstract
In this study, we examined the kinematics of bipedal walking in macaque monkeys that have been highly trained to stand and walk bipedally, and compared them to the kinematics of bipedal walking in ordinary macaques. The results revealed that the trained macaques walked with longer and less frequent strides than ordinary subjects. In addition, they appear to have used inverted pendulum mechanics during bipedal walking, which resulted in an efficient exchange of potential and kinetic energy. These gait characteristics resulted from the relatively more extended hindlimb joints of the trained macaques. By contrast, the body of the ordinary macaques translated downward during the single-limb stance phase due to more flexed hindlimb joints. This resulted in almost in-phase fluctuations of potential and kinetic energy, which indicated that energy transformation was less efficient in the ordinary macaques. The findings provide two insights into the early stage of the evolution of human bipedalism. First, the finding that training considerably improved bipedal walking a posteriori may explain why the very first bipeds that might not yet have been morphologically adapted to bipedal walking continued to walk bipedally. The evolutionary transition from quadrupedalism to bipedalism might not be as difficult as has been envisioned. In addition, the finding that macaques, which are phylogenetically distant from humans and in which bipedal walking is unlike human walking, could develop humanlike gait characteristics with training, provides strong support for the commonly held but unproven idea that the characteristics of the human gait are advantageous to human bipedalism.
| Original language | English |
|---|---|
| Pages (from-to) | 739-750 |
| Number of pages | 12 |
| Journal | Journal of Human Evolution |
| Volume | 46 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 2004 Jun |
| Externally published | Yes |
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Keywords
- Bipedalism
- Energy cost
- Hindlimb joints
- Inverted pendulum
- Macaca fuscata
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
Cite this
Do highly trained monkeys walk like humans? A kinematic study of bipedal locomotion in bipedally trained Japanese macaques. / Hirasaki, Eishi; Ogihara, Naomichi; Hamada, Yuzuru; Kumakura, Hiroo; Nakatsukasa, Masato.
In: Journal of Human Evolution, Vol. 46, No. 6, 06.2004, p. 739-750.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Do highly trained monkeys walk like humans? A kinematic study of bipedal locomotion in bipedally trained Japanese macaques
AU - Hirasaki, Eishi
AU - Ogihara, Naomichi
AU - Hamada, Yuzuru
AU - Kumakura, Hiroo
AU - Nakatsukasa, Masato
PY - 2004/6
Y1 - 2004/6
N2 - In this study, we examined the kinematics of bipedal walking in macaque monkeys that have been highly trained to stand and walk bipedally, and compared them to the kinematics of bipedal walking in ordinary macaques. The results revealed that the trained macaques walked with longer and less frequent strides than ordinary subjects. In addition, they appear to have used inverted pendulum mechanics during bipedal walking, which resulted in an efficient exchange of potential and kinetic energy. These gait characteristics resulted from the relatively more extended hindlimb joints of the trained macaques. By contrast, the body of the ordinary macaques translated downward during the single-limb stance phase due to more flexed hindlimb joints. This resulted in almost in-phase fluctuations of potential and kinetic energy, which indicated that energy transformation was less efficient in the ordinary macaques. The findings provide two insights into the early stage of the evolution of human bipedalism. First, the finding that training considerably improved bipedal walking a posteriori may explain why the very first bipeds that might not yet have been morphologically adapted to bipedal walking continued to walk bipedally. The evolutionary transition from quadrupedalism to bipedalism might not be as difficult as has been envisioned. In addition, the finding that macaques, which are phylogenetically distant from humans and in which bipedal walking is unlike human walking, could develop humanlike gait characteristics with training, provides strong support for the commonly held but unproven idea that the characteristics of the human gait are advantageous to human bipedalism.
AB - In this study, we examined the kinematics of bipedal walking in macaque monkeys that have been highly trained to stand and walk bipedally, and compared them to the kinematics of bipedal walking in ordinary macaques. The results revealed that the trained macaques walked with longer and less frequent strides than ordinary subjects. In addition, they appear to have used inverted pendulum mechanics during bipedal walking, which resulted in an efficient exchange of potential and kinetic energy. These gait characteristics resulted from the relatively more extended hindlimb joints of the trained macaques. By contrast, the body of the ordinary macaques translated downward during the single-limb stance phase due to more flexed hindlimb joints. This resulted in almost in-phase fluctuations of potential and kinetic energy, which indicated that energy transformation was less efficient in the ordinary macaques. The findings provide two insights into the early stage of the evolution of human bipedalism. First, the finding that training considerably improved bipedal walking a posteriori may explain why the very first bipeds that might not yet have been morphologically adapted to bipedal walking continued to walk bipedally. The evolutionary transition from quadrupedalism to bipedalism might not be as difficult as has been envisioned. In addition, the finding that macaques, which are phylogenetically distant from humans and in which bipedal walking is unlike human walking, could develop humanlike gait characteristics with training, provides strong support for the commonly held but unproven idea that the characteristics of the human gait are advantageous to human bipedalism.
KW - Bipedalism
KW - Energy cost
KW - Hindlimb joints
KW - Inverted pendulum
KW - Macaca fuscata
UR - http://www.scopus.com/inward/record.url?scp=3042841706&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=3042841706&partnerID=8YFLogxK
U2 - 10.1016/j.jhevol.2004.04.004
DO - 10.1016/j.jhevol.2004.04.004
M3 - Article
VL - 46
SP - 739
EP - 750
JO - Journal of Human Evolution
JF - Journal of Human Evolution
SN - 0047-2484
IS - 6
ER -