Accurate skull measures will improve vehicle safety
Evidence that women's skulls are thicker than men's, but that both shrink slowly after reaching adulthood, could help the automotive industry to design more effective devices for protecting the head in vehicle collisions and other accidents.
The measurements were made by a team of researchers at China's Tianjin University of Science and Technology led by Jesse Ruan of the Ford Motor Company, who uses a non-invasive imaging technique for determining and analysing the critical geometric characteristics of a person's skull to scan 3000 subjects at a local hospital.
The results, published in the International Journal of Vehicle Safety show that the average thickness of men's skulls was 6.5mm, compared with 7.1mm for women. Men's skulls were an average 176mm front to back and 145mm wide, while women's averaged 171mm by 140mm.
Although having a thicker skull can help minimise the damage caused by a head injury, skull shape is also known to play a part. Exactly how the two factors are related is uncertain, with most previous studies simply extrapolating from smaller to larger skull and thickness to predict the likely effects of an impact. According to Ruan, a detailed statistical analysis of the various measurements for all 3,000 people scanned shows that the distribution of skull size, shape and thickness does not follow a so-called 'normal' distribution pattern and so such extrapolations may be invalid.
"Skull thickness differences between genders are confirmed in our study. The next step will be to find out how these differences translate into head impact response of male and female, and then we can design the countermeasure for head protection," said Ruan. "Reliable biomechanical geometric data of the human skull can help us to better understand the problem of head injury during an impact and help in the design of better head protective devices."
Image: Women's skulls are smaller than men's, but thicker