What shape is the spine of modern apes?

The spine of modern apes has a C-shaped curve, which is a characteristic that distinguishes their skeletal structure from that of humans. This C-shape is adapted for their arboreal lifestyle, allowing for greater flexibility and balance while they swing through trees and navigate their environment. The curvature helps distribute body weight in a way that supports their movement patterns, which include hanging, climbing, and brachiating.

In contrast, humans possess an S-shaped spine, which has developed to support bipedal locomotion. The S-shape provides stability and balance when walking on two legs and is efficient for upright posture. While the term "curved" might initially seem appropriate, it lacks the specificity needed to accurately describe the unique C-shape found in modern apes. The straight spine option would not correctly reflect the natural curvature of an ape's spine, which would be functionally disadvantageous for their specific locomotion and lifestyle needs.