Occipital Bone Bump: What Does It Say About the Early Human Species and the Musculoskeletal Health of Modern Man?

At the back of our head lies a flat, unpaired bone called occipital bone which forms part of the skull roof. Although this bone does not cause pain or require treatment, it can also become a medical concern if it reaches a specific size. Since the occipital bone bump appears like a horn in the skull, some people strongly dislike it for aesthetic reasons.

Origin and Use of Occipital Bone Bump

In the scientific community, it is widely accepted that the occipital bone bump, also called the occipital bun, is a derived trait of the Neanderthals. Since they co-existed with modern humans for an extended period of time before becoming extinct, the occipital bun is thought to be the result of their interbreeding with early modern Europeans.

In a study published by the National Library of Medicine, the researchers analyzed the human crania of modern humans from Africa and Australia to analyze the relationship between occipital plane convexity and some neurocranial variables. It was found that some of the contemporary crania and those found in the fossil of Homo sapiens show the Neanderthal shape of the occipital plane.

The result of the study indicates that the occurrence of the great convexity of the occipital plane in the two species resulted as a by-product of the relationship between their neurocranial features. It does not also support the theory that the occipital bun in Neanderthal and Homo sapiens developed during ontogeny.

As a highly complex bone, the occipital bun plays three major functions. First, it protects the brain and the nerves and blood vessels connected to it. Second, it forms the mobile and immobile joints, which hold together the bones of the skull. Finally, the occipital bun provides attachment to various muscles and ligaments in the head.

Occipital bone bump, also called exaggerated external occipital protuberance (EEOP), is hardly reported as a normal variant in the medical literature. Since it is frequently found among men, it is often used as a prominent feature in gender determination in forensic investigations.

What Does It Say About Modern Humans?

Recent findings have shown that occipital bone bump is more prevalent in young adults than in older age groups. This was confirmed by a 2016 study conducted by researchers from the University of the Sunshine Coast. Led by David Shahar and Mark Sayers, the team analyzed the X-ray images of 218 young Australians between 18 to 30 years old. They found that 41% of the participants possess a bone growth of about 10-30 mm.

The occipital bun used to be prevalent in older patients due to the long-term load carried by the skeleton. Since most of the growths observed in this study were found in younger people, it suggests that the musculoskeletal degenerative stage can begin and develop silently from an early age.

Further tests, such as MRI scans and blood testing, ruled out the possibility that the growth resulted from genetic factors or inflammation. What makes it even more alarming is that while most bumps measure only a few millimeters, those found in this study project from 10 to 30 millimeters. The researchers believe this might be due to bad posture, which is common among young people.

The result of these studies raises concern regarding the future musculoskeletal health of the younger population. It also serves as a basis for establishing potential strategies for posture improvement.