Electronic Thesis and Dissertation Repository

Thesis Format



Master of Arts




Stock, Jay T.


Relatively longer leg length is a feature of the genus Homo that is often argued to have evolved due to selective pressures from a greater reliance on endurance running. Within the genus Homo, however, Neanderthals had relatively short legs with shorter tibiae – a characteristic that has been hypothesized to be a hindrance for running yet advantageous for locomoting on sloped terrains. This thesis tests three hypotheses relating to lower limb proportions and running performance: does morphological variability correspond with a) speed on flat and uphill terrain during a workout completed by cross-country athletes, or b) athletic performance during a 5-stage ultra-marathon, or c) lab measured running efficiency? The findings show no relationships, or weak non-significant relationships between leg length and crural index with measurements of athletic performance. This suggests that the variability in leg length among Homo sapiens does not have significant energetic consequences.

Summary for Lay Audience

Anthropologists have theorized that relatively longer leg length evolved in the genus Homo approximately 2 million years ago as part of a general adaptation to endurance running. However, within the genus Homo, the Neanderthals presented relatively shorter leg lengths, a feature which has led some researchers to theorize that Neanderthals were inefficient at running, and perhaps locomotion in general. Researchers have used experimental evidence from contemporary humans walking and running on flat treadmills to support these theories, however, Neanderthals frequently lived in mountainous and hilly environments. It has been hypothesized that the unique morphology of Neanderthal lower legs and their short calves relative to total leg length would have been beneficial for climbing sloped terrain – however this has never been directly tested.

This thesis employs three tests to examine how leg length, and calf length relative to total leg length correspond with characteristics of running speed and efficiency on flat and uphill terrain. The first test examines how variation in the leg lengths among cross-country runners relates to how fast they run on flat and uphill segments during a workout. The second test examines how variation in the leg lengths of ultra-runners corresponds with how fast they run during a 5-day race through the Andalucía region in Spain. The third test considers how the leg lengths of the ultra-runners relates to the amount of energy used while running on a treadmill. From these tests, there were no findings to support the theory that longer leg length aids in faster and more efficient locomotion. There were also no findings which supported the theory that relatively shorter calves are advantageous for running uphill. Instead, I suggest that the variability in leg lengths among contemporary humans is not significant enough to display differences in running performance. The greater differences in leg length between species may lead to such energetic differences, but this is not directly testable through experimental methods.

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Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.