Because your footing or other means of support are unfamiliar, sex in unusual places—say, on your office desk or in an airplane lavatory—are a lot more likely to lead to injuries than a complicated pose, Herbenick says, citing research from the University of Maryland.
That said, there are a few positions that are more likely than others to result in injury. From strained back muscles to the dreaded “broken penis,” here are four you may want to avoid—or at the very least treat with respect.
The Eager Chef
The Position: You’re standing on your toes while she’s sitting on a counter in front of you. The sex is … spontaneous.
Why it’s Risky: Most cases of penile fracture—ruptures of the blood-filled tubes in your erection—occur from very vigorous sex, explains Justin Lehmiller, Ph.D., who teaches human sexuality and psychology at Harvard University. If your partner is sitting on a countertop and—in your enthusiasm—you miss your target either high or low, your unlucky penis has nowhere to go but into her pubic bone or the counter.
The Over-Exuberant Swiss Ball Blitz
Why it’s Risky: The Swiss Ball Blitz may add some bounce to your thrusts, but beware: “Penis breaks will be more common in any sex position in which the penis comes fully out of the vagina and then goes back in,” Herbenick stresses. Because the Swiss ball creates an unusual amount of up and down inertia, too much oomph could lead to your schlong slipping out of your girl just before gravity and momentum bring her full weight crashing back down on you.
Also risky . . . Stairway to Heaven, or any pose where she’s in the driver’s seat and the sex is especially vigorous. If she’s on top, you have less control over the in-and-out motion, and so you’re more likely to slip out of her, Herbenick explains.
The Cowgirl + Lean Back
The Position: You’re on your back, she’s sitting on top of you. Rather than leaning forward with her hands on your chest, she’s leaning waaaay back.
Why it’s Risky: Like an elbow or knee, your erect penis can be “hyperextended” if you put too much or too frequent downward pressure on the shaft, finds a study from the University of California, San Francisco (UCSF). Over time, this hyperextension can lead to peyronie’s disease—a buildup of plaques that causes your rod to bend while erect. That can make sex impossible, the UCSF research suggests. If you feel tugging—or even a small joint-like crack near the base of your penis, the angle of your intercourse is a little too extreme. Have her lean forward.
The Pogo Stick
The Position: Think of it as standing missionary. You’re holding up all her weight, bending backward, and—to facilitate the old in-and-out—you’re flexing your knees and bouncing her up and down on your johnson.
Why it’s Risky: Anything acrobatic like this is a lot more likely to lead to back pain or strains for the guy, says Herbenick. Not to mention you could topple if your footing is unsure. The other obvious ouch: The woman’s also at risk of being dropped, Herbenick adds.