An anatomic overview to “manspreading” campaign

Abstract

There is a campaign called “manspreading”. The campaign which started to draw attention to men’s making passengers uncomfortable by sitting with open legs in public transportation, attracted too much attention. When we glance through communal living spaces, we see men mostly sitting with their legs open. Can there be a morphological background of this sitting position? Basically, the pelvis of men and women are different from each other. Angulus subpubicus is bigger in women. In women, the femur head is located to lateral due to excess angulus subpubicus. However, the lower end of femur has to direct to medial to adjust with tibial condyle, that is, it gets closer to midline. Anteversion angle of acetabulum is higher in women. Anteversion with a higher angle means more anteriorly located acetabulum. That is, both femurs have to be more located to the midline. In women, the collodiaphyseal angle and femur neck length is smaller than men. Both of these situations cause femurs to be located close to the midline. Q angle which is used in the assessment of the mechanic and situation of knee joint is higher in women. High Q angle means that femur lower ends are close to the midline. Due to anatomical differences listed above, women’s femurs are located closer to the midline, while the femurs of men are located more laterally. This difference is also reflected in the way they sit.