Help me get to the bottom of this ...

July 24, 2005 10:33 PM

Is there a doctor in the house? Does the human body contain one gluteus maximus muscle (spanning both buttocks) or two (one at the top of each leg)?

I'm pretty proficient at Internet research, but I'm having a hard time nailing down a definitive answer for this. My question: does the human body contain one gluteus maximus muscle (spanning both buttocks) or two (one at the top of each leg)? I'd always thought one, but I'm having difficult confirming this because most anatomy texts online describe the muscles of the thigh / leg, and the accompanying illustrations only show half of the maximus (or perhaps all of the maximus, if there are two).

Also, most sites say that the buttocks are made up of three muscles: the gluteus maximus, the gluteus medius and the gluteus minimus. That would settle the matter, except that it seems like medius and minimus come in pairs (but I could be wrong). So how many muscles, really, form the buttocks?

posted by Shadowkeeper to Science & Nature (8 answers total)

Response by poster: Here is an example of an illustration that makes it looks as if there is one gluteus maximus muscle per leg.
posted by Shadowkeeper at 10:43 PM on July 24, 2005

I would say one, see the wikipedia article here. Also, since normal contraction causes simultaneous movement on both sides -- there should be only one.
posted by ruwan at 10:47 PM on July 24, 2005

Response by poster: Wikipedia was the first place I looked, and, based on that illustration, it looks like the g.m. is a single muscle. But check out the definition of "gluteus maximus" in Merriam-Webster: "the outermost of the three muscles in each buttock ..." The phrase "each buttock" makes me thing they come in pairs ...
posted by Shadowkeeper at 10:57 PM on July 24, 2005

Best answer: Two. Definitely, incontrovertibly two, innervated each by the inferior gluteal nerve (right and left).

This is a decent pictorial if you care to view such a thing.
posted by ikkyu2 at 11:00 PM on July 24, 2005

Two, there are medius and minimus muscles, too.
posted by gramcracker at 11:47 PM on July 24, 2005

There are total 2 gluteus maximus, 2 gluteus medius and 2 gluteus minimus - one each for each buttock.
Refer to - The Muscles of the Gluteal Region
See Image
posted by webmeta at 4:11 AM on July 25, 2005

Best answer: Since normal contraction causes simultaneous movement on both sides -- there should be only one.

I'm guessing ruwan is not a bellydancer. In Middle Eastern dance, you can shake your hips by squeezing the right glute, then the left, then the right, etc. (your knees should be bent, your feet should be together, and your pelvis should be tucked underneath you). From experience, you definitely have a separate muscle in each buttock.

Although I've gotten pretty good at squeezing the left and right separately in rapid succession, my teacher is far more impressive--she can separately contract the gluteus maximus, medius, and minimus in each buttock. She can direct each buttock to jut down, straight out, or up.

Most mere mortals have no way to isolate these muscles from one another. When she puts the three together, it's like her bottom has lept off of her body and then returned. Then again, she's been doing this since she was 2 years old. Sigh.

/bellydancing derail
posted by equipoise at 7:43 AM on July 25, 2005

I've tried to clarify the Wikipedia article a bit.
posted by mendel at 9:53 AM on July 25, 2005