Bike riding cuts off blood flow to men's genitals

Is it just an urban myth, or can long-term bike riding cause sexual dysfunction in men?

Previous studies have not shed much light on the question, says Dr. Craig Niederberger, professor and head of urology at the University of Illinois at Chicago College of Medicine, because they have not shown whether bike riding actually cuts off blood flow to men's genitals.

It had not been possible to measure exactly where and how much pressure a bike seat exerts during a ride. Some earlier studies had measured the pressure on the bike seat, but not on the men's anatomy.

"And we really aren't concerned with what the bicycle is feeling," said Neiderberger, who is also professor of engineering at UIC.

Niederberger and colleagues in engineering, urology and radiology designed a study to precisely measure pressure on the male anatomy. Volunteers will ride their bikes out on the street while a device designed and patented by the UIC researchers records data in real time as they try out six different seat designs.

The device, designed by the researchers working with UIC engineering students, can measure pressure on the artery supplying blood to the penis. The thin, flexible sensors are comfortable to wear and send information to equipment compact enough to wear in a backpack while riding.

A radiologist uses ultrasound to determine how much pressure completely blocks blood flow in each volunteer. That amount can differ for each man, according to Niederberger.

With four sensors attached to the skin above the blood vessels, the men ride for five minutes on the six different seats -- some of classic design, and some modified in shape or with padding intended to improve comfort.

Many new bicycle seats are designed to be more comfortable, but whether they are better for the men riding them is pretty much just a guess, Niederberger said.

"So far, we're seeing a surprising amount of variation in how different seats affect different men, depending on their anatomy, their riding posture, and their riding habits," Niederberger said. "The question we would like to answer eventually is whether we can design a universal seat that is good for each and every man."