Does this word look like it wants to be in some other order? Or perhaps as though it’s shorter than it should be – maybe cut down from psoriasis?
Well, if you spend a lot of time sitting at a desk, your psoas might be out of order – by being shorter than it should be.
It? Yes, psoas is singular. It’s sort of like biceps, but also in a way opposite. Biceps is a singular word that looks like a plural and is often taken for one. Psoas is a singular word that was originally a plural word but got taken for a singular. It comes from Greek, psoa, which had an accusative plural of psoas and a nominative plural of psoai. So now the plural of psoas my be rendered as psoai, even though psoas was originally as plural as psoai: it’s getting pulled sideways instead of up or down. But since it passed through Latin on its way to English, you can also see psoae.
Naturally, we pronounce it without the p – so it sounds like “so us.” Or you could say it like “so ass,” I suppose. Try not to say “so as.”
But what is the psoas? It’s the thing my wife was stretching this morning when she put one foot in a skate and held it over her head, pulling it up from the back (not the side) – while standing on the other foot, of course. It’s also the thing that’s probably at the root of some back problems I’m having, even though it’s not in the back.
It’s a muscle that attaches to your spine and the top of your femur, coming around the front way. It’s much involved when you walk or run: you contract and release it with every one of your steps (pasos in Spanish, just incidentally). (Learn more about it and how to stretch it at stronglifts.com and runnersworld.com.) You stretch it when you twist, and since there are two of it, you can – if you want – see them represented with the s and s in this word.
And if you’re sitting too much of the time, it can get shortened and start making trouble for your back. Since it opposes the gluteus maximus, it can ultimately lead to overstrain on that part of your body (not to mention the back compression it can cause, which can make further trouble). Thus any pronunciation that sounds like “sore ass” is not so far off the mark. Ah, the heartbreak of sore asses, thanks to an overshort psoas.