A research team from the University of Waterloo in Canada made history by documenting the way the spine moves during sex. It's the first time science has experimented on the subject, and researchers concluded that doggy-style sex could be the best choice for those with back pain.
"Any family doctor will tell you that couples often ask them how to manage their back pain during and after sex. Many couples will remain celibate because one night of love-making can lead to months of back agony," says Dr. Stuart McGill, of Waterloo's Faculty of Applied Health Sciences.
"Until now, doctors have never had any hard science to base their recommendations upon."
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Working with 10 healthy couples, the research team captured their mattress mambos using advanced motion capture technology as they attempted five different sex positions including missionary, spooning and two variations of doggy-style.
Participants were asked to signal the researchers when they had reached their natural coital rhythm at which point data collection began to examine the thrusting techniques, zeroing in on the spine and pelvis with a total of eight optoelectronic motion capture cameras.
Data was processed using visual 3D software to create an atlas about sex and the spine, the first biomechanical analysis of coitus using advanced technology, and doggy style sex emerged as the most spine-friendly sex position for men.
"For the first time ever, we now have very solid science to guide clinicians on their recommendations for patients who suffer debilitating back pain, but still want to be intimate," said Natalie Sidorkewicz, a PhD candidate at Waterloo and lead author on the paper. "This has the potential to improve quality of life -- and love-life -- for many couples."
Examination of thrusting data gathered by electrodes attached to participants' muscles revealed that male orgasm engages the abdomen and buttocks more than the back muscles.
Researchers saw a large degree of variation in spine motion between participants, indicating a possible reason why some men complain of back pain during orgasm.
"Many of the back pain patients that we see have told us that they experience elevated levels of pain during orgasm, to the point where they will avoid having one during sex with their partner," says Sidorkewicz.
"These initial findings help us to begin to understand what might be provoking their pain during the moment of climax."
Female statistics are soon to be released by the researchers, likely in the coming month, and the next phase of the study will explore sex and hip pain.
The paper was published in the journal Spine.