A shot of “manspreading” in action from the crowdsourced Tumblr, Men Taking Up Too Much Space On The Train.

“I’m not going to cross my legs like ladies do,” Fabio Panceiro told the New York Times last week, “I’m going to sit how I want to sit.”

He’s not alone in his sentiments about New York’s Metropolitan Transit Authority’s (MTA) new campaign to discourage “manspreading,” the practice of male passengers, essentially, feeling the need to open their legs as widely as possible while riding public transportation.

(The city agency is also encouraging subway passengers to please not take up extra seats with backpacks and packages, and instead keep those objects situated in their — compact — laps.)

The slogan for the city’s campaign is “Courtesy Counts: Manners Make a Better Ride” and many other cities across the country have engaged in similar campaigns to curb the unwieldy, sometimes graphic, seated position.

In addition to being generally impolite, some women feel that the posture is not just a subtly aggressive statement of male privilege, but often also a potentially threatening one. By manspreading, a male passenger is not only insisting his right to take up as much space as he desires in public, regardless of the needs or desires of others, but can also use his physicality as a means of intimidation.

Manspreading, some argue, is a form of passive assault.

Yet men’s rights activists in both the U.S. and Canada have been outspoken in their insistence that sitting with their legs spread out is not only their god-given right, but also necessary for their health.

One group, the Canadian Association For Equality (CAFE) have started an online petition to speak out against the Toronto Transit Authority’s similar encouragement to their male passengers to please keep their legs closed. As of yesterday, the petition has 820 signatures.

“This sets a very bad precedent as men opening their legs is something we have to do due to our biology,” states CAFE in their Change.org petition. “It sometimes can be physically painful for us to close our legs and we can’t be expected to do so. We can’t force woman to stop breast feeding on busses or trains and we can’t force them to stop bringing strollers on, why should we force men to close their legs? This is sexism plain and simple and it cannot be passed.”

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But — patriarchal pride aside — there seems to be little medical data to back these claims up.

“There can certainly be some conditions that would make it uncomfortable for a man to sit with his legs together,” Dr. Michael Eisenberg, a Yale-trained MD and assistant professor of urology at the Stanford School of Medicine tells Yahoo Health. “After certain procedures of the scrotum, it can be uncomfortable and harmful to put undue pressure on the area during recovery. Moreover certain conditions that involve fluid accumulation or hernias in the groin/scrotum can make it difficult to sit with one’s legs together.”

Related: Is Sex With A Circumcised Man Different?

However, barring a recent scrotile surgery (such as a vasectomy) or a penile surgery (such as a penile prosthesis implant), there is no medical reason for a man to need to sit with his legs spread out at any time, and certainly not for the short time he is seated while riding public transportation.

“There is no convincing data that sitting with one’s legs closed will have a large impact on sperm production or testicular function….[S]imply sitting with legs closed, especially for a relatively short commute, should be fine,” says Dr. Eisenberg.

Conversely, should these men’s rights groups be truly concerned with the health and well-being of their prostate, they would be best served in ending their online campaigns and getting off the computer: “Using a lap top can increase scrotal temperatures significantly,” Dr. Eisenberg comments, a known cause of male infertility.

So when it comes to manspreading, perhaps the City of Philadelphia’s recent campaign to curb the public transport habit best sums it up: “Dude It’s Rude… Two Seats — Really?”

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