London, Jan 22 (IANS): A team of Canadian researchers has discovered that the "women on top' sex position is most dangerous for men, responsible for half of all penile fractures in the bedroom.

"Our study supports the fact that sexual intercourse with 'woman on top' is the potentially riskiest sexual position related to penile fracture," the authors wrote.

For the study, the team looked at three hospitals in Campinas, a city of three million people in Brazil, used hospital records and in some cases interviewed the patients, Telegraph reported.

They looked at patients with suspected "penile fractures" over a 13-year period.

Half of them, with average age 34, reported hearing a crack before experiencing pain, with some also suffering swelling. Some of them waited up to six hours before seeking medical help.

"Our hypothesis is that when woman is on top, she usually controls the movement with her entire body weight landing on the erect penis, not being able to interrupt it when the penis suffers a wrong way penetration," the authors noted.

"On the contrary, when the man is controlling the movement, he has better chances of stopping the penetration energy in response to the pain related to the harm, minimising it," they added.

Penile fracture is a relatively uncommon clinical condition that causes fear and embarrassment to the patient and can hamper sexual functions.

The research was published in the Advances in Urology journal.