A paper published in the Journal of Tissue Viability last year by S.E. Sonenblum, S.H. Spingle, J.M. Carthcart, S. Mix-a-Lot, and R.J. Winder described the results of the careful observation of the buttocks of "an able-bodied female" as she sat down. While such anatomical study is not new, the equipment used to do so was. The scientists used an MRI scanner to examine the movement of the buttocks in ways undetectable to the naked eye. They were able to create a three dimensional computer generated model of the woman's buttocks. Here are their findings:
MRIs indicated a marked decrease in muscle thickness under the ischial tuberosity during loaded sitting. This change in thickness resulted from a combination of muscle displacement and distortion. The gluteus and hamstrings overlapped beneath the pelvis in an unloaded condition, enveloping the ischial tuberosity. But the overlap was removed under load. The hamstrings moved anteriorly, while the gluteus moved posterior-laterally. Under load, neither muscle was directly beneath the apex of the ischial tuberosity. Furthermore, there was a change in muscle shape, particularly posterior to the peak of the ischial tuberosity.
What is the significance of this study?
3D imaging of the seated buttocks provides a unique opportunity to study the actual buttocks response to sitting.
I'll bet it does.
-via Seriously, Science?