If you are a male bicyclist—as is more likely in some nations than in others—consider the implied warning in this new medical study. Men of The Netherlands, men of Denmark, men of Germany—Beware!
The study is “Effect of Oscillation on Perineal Pressure in Cyclists: Implications for Micro-Trauma,” Thomas Sanford, Adam J. Gadzinski, Thomas Gaither, E. Charles Osterberg, Greg P. Murphy, Peter R. Carroll, and Benjamin N. Breyer, Sexual Medicine, epub 2018. The all-male authors, at the University of California, San Francisco, report:
Genital numbness and erectile dysfunction in cyclists may result from repeated perineal impacts on the bicycle saddle (micro-trauma) that occur during routine cycling….
METHODS: Participants were fit to a study bicycle to ensure all cyclists had the same torso angle (60 ± 1 degree) and maximum knee angle (150 ± 1 degree). A lever system was used to generate oscillation events of 3 progressively increasing magnitudes. Perineal pressure was continuously measured using a pressure sensor on the bicycle saddle….
CONCLUSION: …We found a strong linear relationship between oscillation magnitude and perineal pressure during cycling, which was mitigated by a seatpost shock absorber. The use of shock absorption in bicycle design may reduce perineal micro-trauma and potentially improve cycling-associated perineal numbness and erectile dysfunction.