| These bones were made for jogging |
Feature Function Comments
Shorter Achilles tendon( shorter calcaneal tuber)
Energy storage
Running requires more energy storage and release in muscles and tendons than walking. A shorter calcaneal tuber, which is indicative of a short Achilles tendon, has been correlated with
Longitudinal arch
Increased lower limb length
Shock absorption and energy storage
Shock absorption and energy storage
Increased stride length
Stores 17 percent of strain energy, which is needed during push-off in running( Kerr et al. 1987, 148).
A secondary indicator of the presence of a longitudinal arch( Bojsen-Møller 1979, 166).
Longer stride length requires less oxygen consumption during locomotion in many terrestrial mammals,
|
|
Williams 1982, Pontzer 2007, 1760) |
Increased lower limb / joint robusticity |
Stress reduction |
Running causes an increase in mechanical loading. |
Shortened toes( Rolian et al 2009, 718)
Table 2. Anatomical features used in this study.
Feature |
Improves Walking |
Improves Running |
First Seen |
Achilles tendon length No1 Yes, 2,3 Homo sapiens3 Longitudinal arch Yes4 Yes5 Australopithecus afarensis? 6, Homo habilis7
Yes4 Yes5 Australopithecus afarensis6 Increased lower limb length Yes8 Yes9 Homo habilis10
Increased lower limb / joint robusticity
Shortened toes Yes4 Yes14
Probably11 Yes12 Homo erectus13
Homo habilis7, Homo sapiens / Homo neanderthalensis14
Table 3. Appearance of anatomical features in the fossil record.
Gaining access to original fossil hominin specimens
to assembling the necessary data exclusively from literary sources. Any and all literature on skeletal elements of fossils ranging from 3.2 million years old to modern humans were examined for the presence or absence of a set of skeletal traits( tab. 2). Where possible, measurements from the femur were collected to infer if changes in morphology between hominin species. Due to differences in measuring techniques between articles, not enough data could be collected to run statistical tests.
Results
Homo erectus, and that they are more likely related to
( Bramble and Lieberman 2004, 346). All lower limb skeletal features under study in this paper, with the exception of the calcaneal tuber and increased
hominin species older than Homo erectus( tab. 3). Femoral length, which was used as a proxy for limb length, increased over evolutionary time. An increase can already be observed between Australopithecus afarensis and Homo habilis.
2017 | INTER-SECTION | VOL III | p. 9