Neanderthals are some of history’s worst victims of bad PR. As we continue to discover, Neanderthals weren’t crude, uncultured hominins but rather a complex species with sophisticated tools, engravings, and attitudes toward foreigners — albeit with a potential taste for inbreeding. A PNAS study published Monday clears up another misconception we Homo sapiens have always lorded over them: their terrible posture.

Depictions of Neanderthals in pop culture usually show a large-browed, hunched-over individual who looks more like a great ape on all fours than an upright human. That reputation stemmed from a single skeleton from an elderly Neanderthal discovered in La Chapelle-aux-Saints in France, described in 1911 by Marcellin Boule. But as a new virtual reconstruction of the Neanderthal’s skeleton reveals, he and his kin had the type of skeleton that could walk as perfectly upright as any good-postured human today.

"The idea of Neanderthals having a straight spine ‘is biomechanically absurd.’

“I was always convinced that our ancestors as well as the Neanderthals never walked with a semi-erect posture, as this is biomechanically not adequate,” lead author Martin Haeusler, Ph.D., and head of the University of Zurich’s Evolutionary Morphology Group, tells Inverse. “Likewise, the current reconstruction of Neanderthals by some of our colleagues showing a straight spine without the marked sinusoidal curvature of modern humans is biomechanically absurd.”

Here's how Boule represented Neanderthals (left) and humans (right) in 1911. New evidence suggests their posture was a lot better. Wikimedia

Straight Spine vs. Curved Spine

If Neanderthals walked with a hunch, like the old drawings suggest, they would have had straight spines. But the computer model created by Haeusler and his team shows that Neanderthals, like Homo sapiens, actually had a curved lower spine (lumbar region) and neck. By looking at the wear marks on the individual vertebrae that made up these regions, they were able to reconstruct the Neanderthal’s upright posture.

The lumbar curve, as the Smithsonian National Museum of Natural History explains, absorbs the shock of walking upright and is “uniquely human” (that is, within the Homo family).

The new reconstruction of the Neanderthal spine shows the all-important "lumbar curve." Martin Häusler, UZH

They also noticed that the Neanderthal’s sacrum — the triangle-shaped bone between the hip bones — was positioned in the same way as it is in humans. The sacrum supports all the weight from the upper body, so its position relative to the rest of the pelvis shows how the upper body was oriented as well. Wear marks on the hip joints added even further evidence that Neanderthals walked tall.

The Neanderthal's sacrum is positioned in the same way as that of modern humans, suggesting similar posture. Wikimedia

How Boule Made His Error

When he found the Neanderthal skeleton in 1908, Boule didn’t exactly have context for his discovery. “Boule thought that Neanderthals were somehow intermediate between great apes and recent humans — at the time of Boule, there were no other fossil human ancestors known,” says Haeusler.

“Based on his preconceptions, he interpreted any differences in skeletal anatomy compared to recent humans as primitive,” he says. In doing so, Boule didn’t consider the possibility that the Neanderthal’s spine was unusual for Neanderthals — or the possibility that he was simply old.

“He thus failed to take into account the morphological variation among modern humans,” adds Haeusler. “Moreover, he failed to understand the meaning of the degenerative changes of the spine of La Chapelle-aux-Saints.”

The Debate Continues

In 2018, research published in Nature Communications also used 3D reconstruction to show that a Neanderthal skeleton found in a cave in northern Israel (known as Kebara 2) had a wider ribcage than humans and a “lower degree of curvatures of the spine.” That paper suggested the Neanderthal’s lower spine was straighter than ours, which is more consistent with a stooped-over posture.

In that paper, Haeusler points out, the scientists compared the virtual thorax of the Neanderthal skeleton to CT scans of 16 modern males. As a result, it too failed “to take into account the morphological variation among modern humans.”

Erik Trinkaus, Ph.D., an anthropology professor at Washington University and a co-author on the PNAS study, adds that Kebara 2 has an “exceptionally wide pelvis and therefore is expected to have a rather wide lower ribcage,” and thus is “not necessarily representative of Neanderthals.”

"The issue therefore is one of taking into account the expected variation of both Neanderthals and modern humans.

The debate, ongoing for decades, continues. Nevertheless, on Monday, Haeusler said his team is probably correct: “On the whole, there is hardly any evidence that would point to Neanderthals having a fundamentally different anatomy.” His statement echoes what British researchers, likewise critiquing Boule’s ideas, wrote in 1957 in the Quarterly Review of Biology:

It may well be that the arthritic “old man” of La Chapelle-aux-Saints, the postural prototype of Neanderthal man, did actually stand and walk with something of a pathological kyphosis; but, if so, he has his counterparts in modern men similarly afflicted with spinal osteoarthritis.

And so, it may well be that all the controversy over Neanderthal spines comes down to the fact that some Neanderthals, like some humans, simply had better posture than others. Unfortunately, we don’t have that many Neanderthal skeletons to go by, so it’s important for scientists to keep an open mind as they draw conclusions about the species.

“The issue therefore is one of taking into account the expected variation of both Neanderthals and modern humans,” says Trinkaus.

Abstract: Although the early postural reconstructions of the Neandertals as incompletely erect were rejected half a century ago, recent studies of Neandertal vertebral remains have inferred a hypolordotic, flat lower back and spinal imbalance for them, including the La Chapelle-aux-Saints 1 skeleton. These studies form part of a persistent trend to view the Neandertals as less “human” than ourselves despite growing evidence for little if any differences in basic functional anatomy and behavioral capabilities. We have therefore reassessed the spinal posture of La Chapelle-aux-Saints 1 using a new pelvic reconstruction to infer lumbar lordosis, interarticulation of lower lumbar (L4-S1) and cervical (C4-T2) vertebrae, and consideration of his widespread age-related osteoarthritis. La Chapelle-aux-Saints 1 exhibits a pelvic incidence (and hence lumbar lordosis) similar to modern humans, articulation of lumbar and cervical vertebrae indicating pronounced lordosis, and Baastrup disease as a product of his advanced age, osteoarthritis, and lordosis. Our findings challenge the view of generally small spinal curvatures in Neandertals. Setting aside the developmentally abnormal Kebara 2 vertebral column, La Chapelle-aux-Saints 1 is joined by other Neandertals with sufficient vertebral remains in providing them with a fully upright (and human) axial posture.