TY - JOUR
T1 - Calcaneus length determines running economy
T2 - Implications for endurance running performance in modern humans and Neandertals
AU - Raichlen, David A.
AU - Armstrong, Hunter
AU - Lieberman, Daniel E.
N1 - Funding Information:
We are very grateful to Erik Trinkaus for providing us with unpublished measurements of fossil calcanei and for stimulating discussions of this project. Thanks also to Dennis Bramble, Herman Pontzer, and Mary Stiner for helpful discussions and comments on this topic and to Steve Leigh and two anonymous reviewers for constructive comments on an earlier version of this manuscript. Students in ANTH 395D at the University of Arizona provided valuable assistance during data collection. Scott Squire provided a great deal of assistance setting up and collecting MRI data. Thanks to our subjects for their time and efforts during data collection. Funding for this project was provided by the University of Arizona School of Anthropology to H.A.
PY - 2011/3
Y1 - 2011/3
N2 - The endurance running (ER) hypothesis suggests that distance running played an important role in the evolution of the genus Homo. Most researchers have focused on ER performance in modern humans, or on reconstructing ER performance in Homo erectus, however, few studies have examined ER capabilities in other members of the genus Homo. Here, we examine skeletal correlates of ER performance in modern humans in order to evaluate the energetics of running in Neandertals and early Homo sapiens. Recent research suggests that running economy (the energy cost of running at a given speed) is strongly related to the length of the Achilles tendon moment arm. Shorter moment arms allow for greater storage and release of elastic strain energy, reducing energy costs. Here, we show that a skeletal correlate of Achilles tendon moment arm length, the length of the calcaneal tuber, does not correlate with walking economy, but correlates significantly with running economy and explains a high proportion of the variance (80%) in cost between individuals. Neandertals had relatively longer calcaneal tubers than modern humans, which would have increased their energy costs of running. Calcaneal tuber lengths in early H. sapiens do not significantly differ from those of extant modern humans, suggesting Neandertal ER economy was reduced relative to contemporaneous anatomically modern humans. Endurance running is generally thought to be beneficial for gaining access to meat in hot environments, where hominins could have used pursuit hunting to run prey taxa into hyperthermia. We hypothesize that ER performance may have been reduced in Neandertals because they lived in cold climates.
AB - The endurance running (ER) hypothesis suggests that distance running played an important role in the evolution of the genus Homo. Most researchers have focused on ER performance in modern humans, or on reconstructing ER performance in Homo erectus, however, few studies have examined ER capabilities in other members of the genus Homo. Here, we examine skeletal correlates of ER performance in modern humans in order to evaluate the energetics of running in Neandertals and early Homo sapiens. Recent research suggests that running economy (the energy cost of running at a given speed) is strongly related to the length of the Achilles tendon moment arm. Shorter moment arms allow for greater storage and release of elastic strain energy, reducing energy costs. Here, we show that a skeletal correlate of Achilles tendon moment arm length, the length of the calcaneal tuber, does not correlate with walking economy, but correlates significantly with running economy and explains a high proportion of the variance (80%) in cost between individuals. Neandertals had relatively longer calcaneal tubers than modern humans, which would have increased their energy costs of running. Calcaneal tuber lengths in early H. sapiens do not significantly differ from those of extant modern humans, suggesting Neandertal ER economy was reduced relative to contemporaneous anatomically modern humans. Endurance running is generally thought to be beneficial for gaining access to meat in hot environments, where hominins could have used pursuit hunting to run prey taxa into hyperthermia. We hypothesize that ER performance may have been reduced in Neandertals because they lived in cold climates.
KW - Achilles tendon
KW - Energetics
KW - Locomotion
KW - Moment arm
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U2 - 10.1016/j.jhevol.2010.11.002
DO - 10.1016/j.jhevol.2010.11.002
M3 - Article
C2 - 21269660
AN - SCOPUS:79751527301
SN - 0047-2484
VL - 60
SP - 299
EP - 308
JO - Journal of human evolution
JF - Journal of human evolution
IS - 3
ER -