PelvisBMJ 2002; 325 doi: https://doi.org/10.1136/bmj.325.7358.264 (Published 03 August 2002) Cite this as: BMJ 2002;325:264
Many medical, physiological, or anatomical terms have origins that we never even think of. Often they are no more than Latin translations of the ailment's appearance, as with erythema nodosum (red nodules) or pityriasis rosea (rosy coloured scurf), but sometimes the origins are far more arcane and interesting.
A fine example lies in the pelvic bones. Pelvis itself comes from the Latin for a basin shape. The acetabulum, the hollowing in the bony pelvis that forms the receptive portion of the hip articulation, is named after the small cup used to hold a popular dipping sauce at Roman dining tables. It was roughly four or five centimetres across and held vinegar (acetic acid).
Then we have the sacrum, the triangular bone at the base of the axial skeleton, with its four or sometimes five foramina (from the Latin forare, to bore a hole) allowing passage of the sacral nerves. That the word sacrum shares common sounds with sacred and sacrament is no accident. Sacrum is a shortened form of os sacrum, the Latin translation of the Greek hieron osteon, or sacred bone. In times gone by the sacrum was thought to be the seat of the soul.
The rest of the pelvis is sometimes called the innominate bone (one having no name, and sharing that dubious distinction with a large vein and a large artery further up the body) and consists of the ilium, ischium, and pubis.
Pubis, the bone at the lower front part of the pelvis, simply relates to the genitals, the groin, or pubic hair and shares its root with such words as puberty and pubescence.
Ilium was used in Roman times to describe such diverse concepts as the flank, the sides, and the entrails. The latter might be a confusion with ileum, the third portion of the small intestine. This short region of bowel may in turn have received its modern name erroneously, having been muddled with ileus, now denoting paralysis of the bowel. Ileus originally meant colic, from the Greek eilein meaning to roll.
Ischium has a less complicated background, coming simply from the Greek iskhion, for hip joint. But it does give us the seldom used word ischiatic, meaning pain coming from the hip area. We now shorten this to sciatica.