I finally got ahold of some research on pressure patterns for saddles with and without cutouts.
The study was done by a saddle company and used their brand of saddle, a cut out and a regular with the same dimensions.
And they did the study on WOMEN.
(but they didn't standardize for sit bone dimensions, which is a bummer to me)
The upshot of it was that the total weightbearing was the same for both saddles. The concentration and placement of the weight is what changed. The regular saddle had a fairly even pressure over the entire surface under the soft bits. The cut out had a few spots of intense pressure at points along the cut out, and of course none over the cutout.
So, if your anatomy is such that one of the intense pressure points aligns over a nerve or blood vessel or lymph duct, you will suffer mightily on that particular cut out. If the intense pressure points don't align with any vital bits AND your soft tissue finally gets relief from the pressure you'd have on a regular saddle, happiness ensues.
It's a trade off: take the pressure from this large space and concentrate it on this small space. Which is more irritating? The company concluded it was important for them to continue making both saddles due to the variety of female anatomy.
I'm guessing they will use the info from the study to design better cut-out shapes, too. Maybe avoid some of the real hot-spots of pressure.
BTW: I did try riding on one of the saddles in this study a couple months ago. It was agonizing for me because it was just too narrow for my honking gigantic sits bone span. Meanwhile, the owner of that saddle has happily ridden thousands of miles on it, replacing it with the same saddle every time.
Oh, and quick "do I need a cut-out" test: (highly subjective and YMMV) Sit on the front half of a plain wooden chair in your underwear. Keep your back straight and hinge forward from your hip joints. Lean forward until your elbows are resting on your knees. (mimicking torso angle at riding position) Are your soft bits smooshing into the chair? You might want a cut-out. Not smooshing, and you feel you could sit that way no problem? You might need a wider (to support your sit bones completely) or less padded (so excess padding doesn't press upward into your soft bits) saddle than your current one.
Edit to add: the study had some really gross pictures of labial lymphodema caused by poor fitting saddles. Since this is a family forum I won't post the link here, but if you want it PM me.
Last edited by KnottedYet; 04-06-2008 at 06:32 AM.
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