A study using motion capture technology provides new information on the spinal strain produced by various sexual positions—suggesting that one position commonly recommended for all men with low back pain is not actually the best choice, reports a study in the journal Spine. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.
The results provide a more scientific basis for making individualized recommendations regarding sexual positions for men with low back pain, according to Natalie Sidorkewicz, MSc, and Stuart M. McGill, PhD, of the Spine Biomechanics Laboratory at University of Waterloo, Ont., Canada.
High-Tech Study Measures Spinal Strain in Five Positions
The study included 10 healthy young couples in established relationships. All participants were free of back, hip, or other problems affecting sexual activity. In the biomechanics laboratory, the couples were asked to perform five different sex positions in random order. These included two variations of the “missionary” position, two variations of the “quadruped” (on hands and knees) position, and a “spooning” position.
The study used motion capture technology—like that used in digitally animated movies—to track the motion of the partners’ spines. The researchers were able to measure spinal motion and estimate strain on the male partner’s spine for each position.
The results showed significant variations between positions, in terms of the rate and extent of spinal movement. Recommendations for patients with back pain would depend on the type of movements that trigger pain, the researchers point out. For example, for a “flexion-intolerant” patient—pain induced by bending the spine forward—a quadruped position with the woman supporting her weight on her elbows and knees would place the least strain on the male partner’s spine.
The next best position would be the missionary position, with the man supporting his upper body with his hands as opposed to his elbows. Such “seemingly subtle” changes in posture appear to have a significant effect on spinal motion and strain.
Results Question Advice on ‘Spooning’ Position
The study also found that the spooning position produced the greatest strain on the male partner’s spine if they were flexion-intolerant. That’s of special interest, because the spooning position has commonly been recommended for all patients with low back pain. Ms Sidorkewicz comments, “These previous recommendations for men and women with any type of back pain were based on speculation, clinical experience, or popular media resources—not scientific evidence.”
Many patients with low back pain have pain during intercourse, which can lead to reduced sexual activity. In previous survey studies, men with low back pain have reported “marked discomfort” during intercourse, with difficulties in finding a pain-free position and with pelvic thrusting.
The new study is the first to measure the effects of various sexual positions on spinal motion and strain. The results—together with information on the types of movements triggering the patient’s pain—will help in making recommendations for sexual activity in men with low back pain.
Sidorkewicz and McGill acknowledge some important limitations of their study—particularly the focus on “male-centric” positions, which reflected constraints of the motion capture technology. Future studies will look at female-centric positions, biomechanical effects in patients with actual back pain, and the effectiveness of different movement pattern and posture interventions.
The researchers hope their study will help to promote communication about sexual activity between patients with back pain and their health care providers. “Many health care practitioners feel uncomfortable discussing their client’s sexual needs or do not address these needs at all, ” they write. “Perhaps the provision of recommendations qualified with empirical data will not only substantiate their clinical advice, but also facilitate dialogue between health care practitioners and their patients regarding this important issue.”