measuring sit bones

this is interesting, Knotted. one of the participants @ the Women's Leadership Conference @ USA Cycling shared some information with us about her recent prolapse and the Manchester Procedure and basically told us that pelvic floor failure is more common with cyclists than we think. I don't really have any information about that, but I do know some women who've ridden for extended periods (8-10 years) who have suffered some sensory loss, incontinence, etc.

Hypothetically, do you think there's a relationship here?

Lorri

ps -- I can't ride a saddle without a cutout....

Like Knotted, I am also riding a Brooks, B68 - and I haven't found any other saddle that actually let me sit On the sit bones. (Okay, I lie - but I'm not about to put a phone book sized cruiser saddle on my road bike.) When I ride a standard saddle, even the wide ol' 155+ from Specialized - ow the pain! It hurts to walk or sit for days after - and introduces significant tailbone pain, plus numb toes & hands. Even tho my Brooks isn't 100% ideal and doesn't always dissapear beneath me, it's unreal the difference to be supported correctly on a saddle. I wish I could buy a saddle with a similar fit from some of the other manufacturers, as I'm a little nervous to abuse the leather in cross season.

I have to 2nd the motion that cutouts & tons of padding stink!

I have 160mm seatbones (according to the new Trek measurement thing). Most of the saddles in that size are padded to he** and back with some sort of cutout. They are comfy at first until the padding breaks down and starts to squish the cutout closed... with your soft tissue inside :eek:

I need SOME sort of relief up there (which is why the Brooks never worked for me- way too much pressure when in the drops), but having that relief clogged up by excess foam is almost as bad as nothing at all!

I'm still waiting for someone to come out with the perfect saddle- very wide, minimally padded, relatively T shaped, with a channel or cutout for pressure relief. Under 300g would be nice, too since I'm spending so much to make the remaining parts of my bike lighter...

Great thread.
I am a brooks b67 rider, my sit bones measure apparently about 140 cm (using paper, ruler and fingers), but i've tried a lot of different saddles only to go back to the old safe and true. Yes, sometimes I get sore (from a deep pothole bump for example) but I can sit for hours without irritating delicate tissues.

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Originally Posted by KnottedYet

Their idea is that women should be sitting on the rami, not the sit bones.

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OK, I finally gave up an googled "rami". I wasn't sure if it was a slang term that would pop up something to get me in trouble at work. :eek:

This explains it nicely: http://en.wikipedia.org/wiki/Superior_pubic_ramus

Quote:

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Originally Posted by Cindyloo

OK, I finally gave up an googled "rami". I wasn't sure if it was a slang term that would pop up something to get me in trouble at work. :eek:

This explains it nicely: http://en.wikipedia.org/wiki/Superior_pubic_ramus

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Thanks Cindyloo, I tried finding a diagram too but for some reason I couldn't.

I think this must be where I sit. My Fizik Arione is very, very comfortable to me, but I'm quite sure it's narrower than my sitbones. I've never measured them, but I'm a pear shape with a wide pelvis (even when I'm thin :D), and I'm sure they're not on the narrow side. But I find this saddle more comfortable than wider ones I've tried, particularly wider saddles that have less of a smooth transition from nose to rear (if there's a pronounced flare I tend to "run into it"), and wider saddles that are less convex than the Arione from side to side. My bf has a 143mm Specialized Alias, which is both significantly wider and has a cutout, and it's much less comfortable to me. This has puzzled me for a while, but maybe this explains it. The Arione must be the perfect shape for my rami :p!

Andrea: from your description, we are looking for similar things, so if you find anything great, let me know.

Knotted: I had my anterior pubic ramus removed ~8 years ago when I had an aneurysmal bone cyst grow in it and break it. (I'm assuming that anterior p.r. and superior p.r. are the same thing) .. So, what does my asymmetry mean for my seat comfort, do you think?

BEANE, and you still ride???? (what kind of saddle??)

Yeah, I was told that it was non-weightbearing and that I wouldn't miss it... but maybe the doc wasn't considering my future cycling. I have run the gamut of saddles and have yet to find anything I'm completely happy with. The closest was the old specialized dolce, but mine starting squeaking and was a little too cushy for real road riding.

In the cartoon on the wikipedia page, the bone I'm missing is part 4, right where the "b" is.

The new saddles I was talkin' to the dude in SF about are meant to weightbear on the area where the "c" is on the wiki picture. When I told the head of our pelvic rehab program about the new saddles, her outraged reaction was pretty classic.

Beane - have you tried one of the really wide and sprung unpadded saddles like the Brooks, or maybe the Selle An-Atomica? Kinda seems like the less mechanical shock you can get into the pelvis, and the more you can weightbear back onto the actual tuberosity, the more stable you'll be. I'm trying to think of ways to compress the area of the missing bone as opposed to forcing it open more (wb on the corner of the triangle rather than on the middle of one of the legs of the triangle. your available wbing corners are the ischial tuberosity and the pubic symphisis. i'd be inclined to try the ischial tub first, but you might consider up near the symphisis) You might also consider trying the new Trek women's saddles when they come out. If you can get one that actually lets you weighbear along the entire length of the inferior ramus, it might be even more stable than anything else. (maybe try a couple sizes and see which works best)

VG - oh, yeah, I think there's a relationship between poor saddle fit and later pelvic issues. The problem from an industry standpoint (as far as I'm concerned) is that once these cyclists are so damaged that they can no longer ride, they fall off the radar of the bike companies. So, no-one is designing the saddle that would have kept my otherwise very healthy 65 year old patient riding. She's old, she's only a woman, she doesn't ride; so she doesn't count in the industry bean-counter's eyes. But a more pear-shaped or more T-shaped or wider cantle or narrower nose or SOMETHING might have kept her from injury and she'd still be riding now.
(and she wouldn't be spending so much quality time with me talking about pee and poop and adult diapers and numbness) (or if she had to anyway because of genetics or posture habits or having birthed 4 kids, she'd at least have a saddle that let her ride despite her pelvic difficulties)

Quote:

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Originally Posted by KnottedYet

The new saddles I was talkin' to the dude in SF about are meant to weightbear on the area where the "c" is on the wiki picture.

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Owie!!!! Really? That hurts just thinking about it--brings back memories of that original ill-fitting saddle that taught me what it feels like when you ride a saddle that is too narrow. OK, I suppose maybe if they got the angle completely right, but it would definitely need a great cutout...and, just why would I trust them to get all of it right?

But, I digress, thank you very much, Knot, for your explanations. I'm in a forever loop of looking for the right saddle. You've armed me (?saddled me?) with more information as I continue my quest. Always informative and helpful. Thanks.

Any mechanical engineers out there? Perhaps the custom saddle business is prime for the pickin's?

Beane-

My LBS told me that the new Trek line will have a less poofy saddle available in wider sizes, so I've got my fingers crossed! They have a couple of men's saddles in that look interesting that I may try in the meantime.

Knot, can't your patient get a recumbent?

Yup, that option is always out there. But why not keep all options open? Let's start a custom bike saddle business! I'm game! :D

BTW: patient details have been altered to protect patient privacy.

Hi Lattae and ladies,

Forgive my intrusion into your forum as a bike tech (male 140lbs) just discovered your posts.
The problem of sit bone anatomy arises daily for women.

Saddle design has improved over the last 5-10 years but remains a problem for certain bum sizes and body weights due to some manufactures adopting a fit-all policy. Where overall construction for safety standards, is measured for rider weights of around 200-220lbs.

I won’t go into detail regarding the differences of male/female saddle designs, soft tissues and cutouts, but a simple test to identify your sit bone dimensions may help with narrowing down your choice of saddles

If you can find a small hard flat topped table (coffee table works well) at a height, where your legs and feet are normally positioned with the pedals at 3 and 9 o-clock.

Sit on the table until you can only feel your sit bones. Rotate your rear end to get the idea of the area needed to be identified.

Place a sheet of non-glossy A4 paper on the table, followed by two layers of tissue on top. Spray a fine water mist to dampen the tissue paper and place another sheet of A4 on top. Sit down and then rotate slightly. If you draw an approximate circle around the two dampened areas on the A4 sheets this should give you a guide to your sit bone centre lines and pressure areas. You can repeat the same test with body angle positioned for bars, hoods and drops, to give an overall picture of the support required.

Hope this may help