Back pain isn’t just one of the most common reasons for skipping work. But new guidelines based on how the spine moves during intercourse could help.

Back pain affects 8 out of 10 people at some point in their lives, and low back pain is the leading cause of disability globally.

Regarding sex, doctors used to recommend the spooning position for people with back pain, despite a lack of scientific evidence to support it.

Based on range of motion, researchers identified the best and worst sex positions for men.

Here’s what they found: • Sexual Position: m QUAD1, a variation of doggy style.

In this variation, the woman is supporting her upper body with her elbows.

Sidorkewicz says flexion-intolerant men – meaning men whose back pain becomes worse when they touch their toes or sit for a long period of time – will likely be much more comfortable using this position.

• Sexual Position: m QUAD2, a variation of doggy style.

In this variation, the woman is supporting her upper body with her hands.The study showed that this position, in addition to the m QUAD1 variation, is considered to be easier on the spine for flexion-intolerant men.Now researchers from the University of Waterloo in Canada have developed guidelines to avoid back pain during sex for men who don’t have a preexisting back or hip condition.“Our analysis of spine motion during intercourse shows that, in fact, the recommended positions for men depend on what movements trigger their pain,” says Natalie Sidorkewicz, a Ph D candidate at the University of Waterloo and lead author on the paper published today in the journal Spine.RELATED: 4 Proven Ways to Stop Low Back Pain The researchers tracked how 10 couples’ spines moved in five common sex positions.Using both infrared and electromagnetic motion capture systems, they measured how the men’s spine moved during sex, and created guidelines for best positions and techniques based on what movements cause pain.