A new study suggests that bike riders risk injury to the kidney or genitalia.
The study also found that kids sustain about 10 times as many of these injuries as adults.
Cyclists are often correctly encouraged to wear a helmet, but the study shows head injuries aren't the only ones they should be concerned about, researchers said.
Co-author Dr. Benjamin Breyer, a urologist at the University of California, San Francisco, said that they were surprised that there were so many injuries related to bike riding, Fox News reported.
The researchers analyzed data that had been collected by the National Electronic Injury Surveillance System between 2002 and 2012. The system includes information on patients who came to the 24-hour emergency rooms of about 100 hospitals nationwide, including eight children's hospitals.
Breyer and his team separated the patients by age group and looked at whether each person had been subsequently admitted to the hospital, which would indicate a relatively severe injury. They excluded injuries that had been caused by a collision with a car.
The study did not examine the severity of injuries in more detail or whether the patients had required a follow-up visit with their doctor afterward.
An average of about 4,000 people sustained bicycle-related kidney or genital injuries during each year of the study, the authors found.
They also discovered that children came to the ER for bicycle-related kidney or genital injuries about 10 times more often than adults: about 448 of every 100,000 children, as opposed to 53 of every 100,000 adults, presented to the ER each year for such injuries.
The study is published in the journal Injury Prevention.
