I found this website http://www.hab-it.com/ written by a PT who specializes in women's health issues. I was amazed to find out some things I didn't know about the female body, specifically the pelvic floor.

In the blog about Cardio here's what she says about bicycling.

"How about biking? Again, I like this exercise because of the position it puts your body in. A good bike fitting will require you to reach forward to your handle bars which will roll you forward onto your sitting tripod, which is your right sit bone, your left sit bone, and your pubic bone. This is a position that frees your tail bone from pressure and automatically activates your TA because of the forward reach of your arms."

The position she describes sounds like it puts more pressure on sensitive parts but I tried it on my first ten miles of the season and it doesn't at all. Yesterday my sit bones were a little sore but once I got going I felt good. Last year at the beginning of the season I was complaining about my saddle and thought I needed a new one. By the end of the season I couldn't ride without lower back pain. Using this posture I had no pain when I got off the bike. I'm a flat back posture and am still learning the neutral posture but I was able to hold onto it on my short rides.

The other benefit is I'm now using my leg/glute/core muscles instead of my lower back. My average speed went up 2 mph over last year without specific training even though I was just tooling around the neighborhood. Now I'm wondering if I need a change in my bike fit as I don't seem to be centered over the pedals any more.

I don't think this is a ploy to keep women from bicycling but I do think it's a lack of understanding of the way a woman's body works and the need for good posture to support the pelvic floor.