It's "directionally" true, but it's a simplification. Our spines have evolved slightly to accomodate an upright posture. The human spine is curved to accomodate

It's "directionally" true, but it's a simplification. Our spines have evolved slightly to accomodate an upright posture. The human spine is curved to accomodate weight bearing while upright, and this particular curvature is not seen in other mammals, including other great apes like chimps and gorillas. Ref: https://en.m.wikipedia.org/wiki/Lordosis https://en.m.wikipedia.org/wiki/Lordosis