KEN IGE / KIGE@STARBULLETIN.COM Bicyclist Atomman Kimm held up a Specialized Body Geometry racing saddle yesterday as fellow rider Pat Ah You waited for the riding to resume.

Study links bike
seats to numbness

A study of bike-riding cops
found high rates of erectile
dsyfunction and groin numbness

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By Helen Altonn
haltonn@starbulletin.com

Honolulu Police Sgt. Glenn Maekawa says his team of bicycle patrol officers is always making adjustments to prevent the kind of problems reported in a study of Long Beach bicycle policemen.

The National Institute for Occupational Safety and Health did research after a doctor reported complaints by the Long Beach police bikers of groin numbness and erectile dysfunction. The study showed cyclists can experience problems ranging from tingling sensation and numbness to sexual dysfunction.

Maekawa's team is constantly switching to different saddles to prevent the tingling, he said, "but, no matter what, after a while it does affect us."

"We take a break, get off the bike and rest until the tingling sensation goes away. ... We don't know in the long run if something will show up as a problem," he said.

In the Long Beach study, researchers compared 17 male bicycle policemen with five nonbiking men. They found the policemen had erections during 27 percent of their sleep cycle compared with 43 percent for the others. About 93 percent of the policemen experienced genital numbness.

DEAN SENSUI / DSENSUI@STARBULLETIN.COM Jarrel Chun-Ming of McCully Bicycle showed some newer bike saddle designs that minimize pressure in the crotch. He said a lot depends on a person's riding position and the time spent on the seat.

The data "suggest that prolonged bicycle riding may have negative effects on nocturnal erectile function and indicate a need for innovative bicycle saddle (seat) designs," the researchers concluded in an article in the November-December Journal of Andrology.

Honolulu bikers acknowledge the risks but say the cardiovascular and other health benefits outweigh potential problems and that various techniques can be used to prevent them.

A person's weight on a narrow bike seat puts heavy pressure on the perineum, the area under the penis and the vagina that contains nerves and arteries to the genitals.

Maekawa's detail has nine bikers, including himself and two bike instructors for the Police Department. He said every police cyclist has a choice of seat, but the ones that work best are too expensive for the department.

The ones they use now cost $30 or $40, and the one they like costs $60, he said.

"The one we have doesn't have an air bladder in it (that can be inflated or deflated to get firmness). It's just a regular seat with a notch in the center."

The harder the seat, the better it is, Maekawa said.

"If it's too soft, somehow it doesn't support you, and you get a tingling sensation a lot faster."

People with "natural padding" also can use a harder seat than those who are thinner, he said.

"It's very individual. It depends on your anatomy and pressure issues -- how thin you are, how your bones lie on it," said Dr. Gary Lattimer, urologist and bicyclist. "A few millimeters make a difference."

Despite a huge increase in biking and the number of triathletes, however, Lattimer said he is not seeing more biker-patients. Manufacturers have tried to modify seats so they do not press on the perineum, he said.

But eliminating central pressure still leaves nerves on the sides of the penis which often get compressed, Lattimer said. Compression can damage the vessels, causing circulation problems and contributing to sexual dysfunction for serious riders.

Lattimer said he has many patients who have had distressing problems despite trying various seats. If they still have numbness or dysfunction after using different seat cutouts, he said: "I tell them they're playing with fire. Bicycling may not work for them. I have two patients on their third seat, experiencing problems again."

Lattimer, who races, said he has no simple advice for bicyclists because it's "trial and error." Like many male cyclists, he uses a woman's saddle with a hole in the center.

Jarrel Chun-Ming, bike department manager at McCully Bicycle & Sporting Goods, said, "The consensus is that it (the impotency issue) has been sensationalized."

He said numbness problems are "not widespread. For more people it just hurts." A lot depends on a person's riding position and time spent on the seat, he said.

John Goody, board member of the Hawaii Bicycling League, which has about 1,000 members, said: "I think most cyclists will just vary their stance and pedaling technique if they get numb. They move around, slide back on seats or stand up."

Huge strides have been made in saddle design with many anatomically contoured to relieve pressure points, he said.

"The odds are much better if you ride that you will have better health than if you sit around and don't do anything," he said.

City bike coordinator Chris Sayers agreed that the health benefits of bicycling far outweigh any possible problems.

"Personally, I ride all the time and have a 4-year-old boy, and it didn't hurt me."

He said about 100,000 mountain and road bikes are registered on the island, including adults and kids, but the figure is believed to be at least double that because many bikes are not registered.

Atomman Kimm, who works at Straub Clinic & Hospital and races with the Tradewind Cycling Team, said most bikers will figure out all the variables, including the angle of the saddle, whether the nose (the front narrow part) is up, down or flat.

"You have to experiment with it. It's like a seesaw. The more you point it down, the less pressure you have on your crotch area, but more on your hands."

Other factors, said Kimm, who worked 11 years for a bike shop, are the seat's height relative to the pedals and how far forward it is in relation to the handlebars.

"It's a balancing act. People get numb hands, also. Most of us will figure out combinations of height, angle and tilt."