Modern human men evolved unique hip 'spring' for efficient walking, Israeli-led study finds

A new Israeli-led study, published in Scientific Reports, reveals that modern human males evolved a unique pelvic structure for efficient walking, challenging previous assumptions about Neanderthal anatomy. Led by Professor Yoel Rak of Tel Aviv University, the research compared Neanderthal male pelvises with those of modern humans, finding that Neanderthals and modern human females share an ancestral pelvic configuration. The modern human male pelvis, however, developed a distinct geometry with forward-shifted hip joints, creating a "spring" mechanism that cushions impact and stores energy during walking. "The male hip joints shifted forward to create a unique, built-in 'spring' mechanism, transforming the male stride into a highly efficient, energy-storing machine built for long-distance walking," the team wrote. This adaptation likely provided an advantage for hunter-gatherer males, while childbirth constraints kept the female pelvis closer to the ancestral form. The findings suggest that the modern human male pelvis, not the Neanderthal pelvis, represents the evolutionary innovation, with implications for understanding human biomechanics and musculoskeletal health.