In 1997, Irwin Goldstein, MD, a well-known impotence researcher and clinician from Boston University Medical Center, asserted that 100,000 men have suffered permanent impotence from bicycling.

New studies presented at the American Urological Association (AUA) in Dallas bring the problem into sharper focus. They provide evidence that the problem does exist, give an idea of its prevalence, and show that female bicyclists aren't immune to perineal injury. (See "Bike-Related Perineal Problems: What About Women?" below.)

A VULNERABLE REGION

Concerns about riding-related impotence problems are not new, says Goldstein. "Hippocrates wrote that sexual problems were common among horsemen," he says. In the modern medical literature, case reports about biking and sexual dysfunction have appeared since the 1970s.

Goldstein says damage can occur when the bike seat - particularly the narrow racing type - focuses body weight on the pudendal nerves and artery, cavernosal artery, surrounding soft tissues, bony structures, and associated sexual organs. "The bike seat is archaic. It's unanatomic," he says. "The perineum is an intricate neurovascular complex, but there are no shoulder pads or helmets to protect it." Compression can lead to nerve damage, cavernosal artery insufficiency, and site-specific vaso-occlusion.

HOW COMMON A PROBLEM?

Scientific evidence and estimates vary regarding the prevalence of impotence among bicyclists. Goldstein and his colleagues at Boston University, in a study being presented at the AUA meeting, compared the rates of sexual and urinary dysfunction for 738 members of a bicycling club and 277 members of a running club who did not bicycle. Researchers found that the level of moderate-to-complete impotence in cyclists was significantly higher than in runners (4.21% vs 1.12%, p = 0.018). The only demographic difference between the groups was a higher rate of hypercholesterolemia among the bikers (10.6% vs 5.2%).

A 1997 cross-sectional study of participants in a Norwegian long-distance bicycle race (540 km) found that of 260 men who answered the questionnaire, 22% reported nerve symptoms such as numbness in the perineal area. Numbness lasted more than 1 week in 11 riders and more than 1 month in 3.

Though the number of men who experience bike-associated numbness or impotence may not be as high as the Norwegian or Goldstein estimates, the relationship between activity and injury is real. Estimates that 50% of men who ride a bike for 2 to 3 hours at a time experience perineal pain or numbness. "And sitting on a bike seat for more than 2 to 3 hours at a time can increase the risk of impotence," he says.

Goldstein estimates male bicyclists experience activity-related impotence. Goldstein says, "I've gotten hate mail (from biking enthusiasts) and have taken a lot of abuse for my claims, but 4% of 50 million bike riders is a lot of people."

DIAGNOSIS & TREATMENT

Cycling-related perineal symptoms, which can be temporary or permanent, include numbness, pain, decreased orgasm sensitivity, and impotence. Numbness is a premorbid symptom, Goldstein says. "It can be a warning sign, but impotence can occur without it." The physical exam in patients who have symptoms doesn't provide much clinical information, he says. Treatment involves rest from biking, Goldstein says. For patients who have veno-occlusion, vascular reconstruction may reestablish potency, "but not everyone is a candidate."

Equipment changes can prevent recurrence. Switching to a recumbent bike can relieve pressure on the perineal structures, and patients should consider switching to a wider bike seat that allows the ischial tuberosities to bear more of the body weight.

REFERENCES

Kita J: Hard ride: some doctors think too much time on a bicycle seat causes impotence. Men's Health 1997;12(8):86-88
Bond RE: Distance bicycling may cause ischemic neuropathy of the penis. Phys Sportsmed 1975;3(11):54-56
Kuland DN, Brubaker CE: Injuries in the Bikecentennial tour. Phys Sportsmed 1978;6(6):74-78
Solomon S, Cappa KG: Impotence and cycling: a seldom-reported connection. Postgrad Med 1987;81(1):99-102
LaSalle MD, Salimpour P, Adelstein M, et al: Sexual and urinary tract dysfunctions in bicyclists. Presented at the 94th Annual Meeting of the American Urological Association, May 4, 1999, Dallas
Andersen KV, Bovim G: Impotence and nerve entrapment in long distance amateur cyclists. Acta Neurol Scand 1997;95(4):233-240
LaSalle MD, Wen C, Choi M, et al: Erectile dysfunction in 81 consecutive riders. Presented at the 94th Annual Meeting of the American Urological Association, May 4, 1999, Dallas

"What about women?"

Bicycle-related perineal problems aren't just men's problems, according to researchers from Boston University. They have conducted a study that they say is the first to document sexual and urinary tract dysfunction in female bicyclists.

The study, to be presented this month at the American Urological Association meeting in Dallas, included 282 female members of a bicycling club and 51 female members of a running club who served as controls. Ninety-eight percent of the bicyclists were road bikers; 11% were racers. Past injuries and symptoms among the bicyclists included traumatic contact with the bicycle top tube (32%), perineal numbness (34%), urethral stricture (1.8%), and pelvic fracture (1.5%). The mean ages of bicyclists and runners were similar (40 + 9 vs 42 + 12). No significant differences were found in the rates of cardiovascular risk factors, education, race, or frequency of sexual intercourse.

The researchers say that similarity between men's and women's bike-related injuries from compression or trauma isn't surprising because certain parts of the male and female sexual anatomy are similar- specifically, the orientation and course of the pudendal neurovascular bundle within Alcock's canal and medial to the ischiopubic ramus.The study, to be presented this month at the American Urological Association meeting in Dallas, included 282 female members of a bicycling club and 51 female members of a running club who served as controls. Ninety-eight percent of the bicyclists were road bikers; 11% were racers. Past injuries and symptoms among the bicyclists included traumatic contact with the bicycle top tube (32%), perineal numbness (34%), urethral stricture (1.8%), and pelvic fracture (1.5%). The mean ages of bicyclists and runners were similar (40 + 9 vs 42 + 12). No significant differences were found in the rates of cardiovascular risk factors, education, race, or frequency of sexual intercourse. The researchers say that similarity between men's and women's bike-related injuries from compression or trauma isn't surprising because certain parts of the male and female sexual anatomy are similar- specifically, the orientation and course of the pudendal neurovascular bundle within Alcock's canal and medial to the ischiopubic ramus.

REFERENCE

LaSalle MD, Salimpour P, Adelstein M, et al: Sexual and urinary tract dysfunction in female bicyclists. Presented at the 94th Annual Meeting of the American Urological Association, May 4, 1999, Dallas

Lisa Schnirring
www.physsportsmed.com