Less Pain, More Pleasure

New study reveals best positions to save your spine

At some point in their lives, most Canadians will experience back pain severe enough to curtail sexual activity. Groundbreaking University of Waterloo research by STUART MCGILL, a professor of kinesiology and NATALIE SIDORKEWICZ, a PhD candidate, is the first of its kind to offer evidence-based solutions. McGill, a professor in the Department of Kinesiology, is a leading expert in spine biomechanics.

In the first biomechanical study of its kind, researchers in the University’s Faculty of Applied Health Sciences documented the way the spine moves during intercourse, and discovered exactly which positions are best for avoiding different types of back pain.

The findings, published in the Sept. 15 issue of the academic journal Spine, shake up traditional wisdom that spooning is the best sex position for those with bad backs, and put Waterloo on the map as a trailblazer for important health research.

“Any family doctor will tell you that couples often ask them how to manage their back pain during and after sex. Until now, doctors have never had any science to base their recommendations upon. Their advice was limited to speculation and assumption.” 


Sexual activity has long been regarded as an indicator of quality of life, with the World Health Organization recognizing sexual relationships as a measurement of health and disability. Yet according to recent surveys, as high a percentage as 84 per cent of men and 73 per cent of women with chronic low back pain experience decreased sexual activity because of their pain.

“Many couples will actually remain celibate because one night of lovemaking can lead to months of back agony,” says McGill. “It’s a pervasive problem, but a completely unresearched topic.”

High-tech approach to studying sex

Led by PhD candidate Natalie Sidorkewicz, the pioneering study combined electromagnetic and infrared motion capture systems — such as those used by filmmakers and video game producers for full computer graphic character animation — to track how 10 couples’ spines moved when attempting five common sex positions. The study was conducted in a controlled laboratory setting, which allowed researchers to accurately measure the motion of each participant’s back.

Electrodes hooked up to abdominal and low back muscles monitored how hard muscles had to work during sex.

Natalie Sidorkewicz

NATALIE SIDORKEWICZ, a PhD candidate in the Faculty of Applied Health Sciences, led the study that combined electromagnetic and infrared motion capture systems to track how couples’ spines moved when attempting common sex positions.


“We were able to determine the position and angle of the spine at each moment in time during intercourse, and see if each sex position engaged low back muscles differently,” 


The high-tech biomechanical approach revealed that when it comes to avoiding back pain during sex, all positions aren’t created equal.

“We found that sex positions that are suitable for one type of back pain, aren’t recommended for another,” says Sidorkewicz.

The finding contradicts the long-held belief that spooning — where couples lie on their sides curled in the same direction — is the most spine-friendly position for men and women with back problems.

“Spooning was often recommended to all men and women with low back pain because it was thought to reduce nerve tension and the load on the tissues. But as we’ve discovered, that is not the case,” Sidorkewicz says.

Article Sidebar, Transformational research

The best sex positions for bad backs

Enjoy the pleasure without the pain! Experts reveal the best positions for people who suffer from back pain

Read More

New guidelines for clinicians

The researchers used their findings to create an atlas, or illustrated set of guidelines, that recommends different sex positions and thrusting techniques based on the type of movement that triggers a patient’s pain. For health care practitioners working with low back pain patients, the atlas is a long overdue resource for reliable recommendations.

“Previous recommendations ignored the fact that there are different kinds of back pain triggered by different kinds of movements and postures,” says Sidorkewicz, who developed the atlas based on two common types of back pain — that induced by arching the spine backwards and that caused by bending it forwards.

“Common motions of the spine that can trigger low back pain are flexion and extension — the technical terms for forward bending and backward arching. Typically, if a patient finds flexion to be painful, they will find relief in extension and vice versa. Since these are also the most common spine motions during sex, patients with one type of back pain may find a certain sex position to be relieving while patients with another type of back pain may find their pain is triggered."

The atlas recommends that men who are flexion- intolerant, those whose back pain is made worse by touching their toes or sitting for long periods of time, replace spooning with doggy-style intercourse. On the opposite end of the spectrum, men who are extension-intolerant, those who experience pain when arching their backs or lying on their stomachs, will likely find sex in the spooning or missionary position more comfortable, in particular when supporting their upper bodies with their elbows rather than their hands in missionary.

The guide also recommends that men use a hip- hinging motion rather than thrusting by bending with their spines.

“The survey reports were all pointing for a study like this to be done,” says Sidorkewicz. “Now we have a very solid science to guide clinicians on their recommendations for patients who suffer debilitating back pain, but still want to be intimate.”

Waterloo in the Media

GLOBAL RESEARCH IMPACT: 43 Countries on 6 Continents

When the peer-reviewed journal Spine published “Male Spine Motion During Coitus: Implications for the Low Back Pain Patient” in September, the paper quickly attracted international media attention for its capacity to improve couples’ health and well-being.

Within the first week alone, more than 300 media outlets covered the study. From The Washington Post to the BBC, the story made headlines in 43 countries around the world — reaching a total global audience of more than 29 million.

Article Sidebar, Transformational research

The ethics of studying sex

How do you get ethics clearance — and find participants? Researchers reveal the challenges surrounding studying sex

Read More

Understanding orgasm

The study also shed light for the first time on the mechanics of the male orgasm. Electrodes hooked up to the male participants’ muscles revealed that while orgasm may exacerbate back pain, back muscles aren’t actually to blame.

“We were quite surprised to find that consistently, abdominal and hip muscles were much more active than the back muscles we monitored," says Sidorkewicz.

Spine motion, on the other hand, varied with the individual. Some males experienced a drastic increase in flexion or extension, while for others, spine motion did not change much at all.

“Many of the back pain patients we see have told us they experience elevated levels of pain during orgasm, to the point where they will avoid having one during sex with their partner. These initial findings help us to begin to understand what might be provoking their pain during the moment of climax.” 


Study to expand

The next phase of the study, which Sidorkewicz will complete as her PhD thesis, includes examining participants with different kinds of back and hip pain. Sidorkewicz hopes to examine spine and hip motion as well as muscle activity in sex positions where the female controls the motion — as in the woman on top position. These studies will allow her to further develop the breadth of clinical recommendations.

“We know from survey studies that many health care practitioners are not inclined to discuss the sexual needs of their clients, despite the fact that their patients consider their sexuality to be an important domain that is never actually talked about in relation to their condition,” says Sidorkewicz.

“This research is not only about guiding clinicians to make better, more accurate recommendations. We’re hoping to help facilitate conversations between the patient and practitioner and also between partners who live with this debilitating pain every day. It’s about enhancing the quality of life of these couples by helping them maintain healthy sexual relationships.”