Sidorkewicz Natalie, McGill Stuart M
Department of Kinesiology, Spine Biomechanics Laboratory, University of Waterloo, Waterloo, ON, Canada,
Eur Spine J. 2015 Mar;24(3):513-20. doi: 10.1007/s00586-014-3626-y. Epub 2014 Oct 24.
To describe female lumbar spine motion and posture characteristics during coitus and compare these characteristics across five common coital positions. Exacerbation of low back pain during coital movements and positions is a prevalent issue reported by female low back pain (LBP) patients. To address this problem, the first study to examine lumbar spine biomechanics during coitus was conducted.
Ten healthy males and females performed coitus in the following pre-selected positions and variations: QUADRUPED (fQUAD1 and fQUAD2 where the female is supporting her upper body with her elbows and hands, respectively), MISSIONARY (fMISS1 and fMISS2 where the female is minimally and more flexed at the hips and knees, respectively), and SIDELYING. An electromagnetic motion capture system was used to measure three-dimensional lumbar spine angles that were normalized to maximum active range of motion-a transmitter and receiver were affixed to the skin overlying the lateral aspect of the pelvis and the spinous process of the twelfth thoracic vertebra, respectively. To determine if each coital position had distinct spine kinematic profiles (i.e., amplitude probability distribution function and total range of lumbar spine motion), separate univariate general linear models followed by Tukey's honestly significant difference post hoc analysis were used. The presentation of coital positions was randomized.
Female lumbar spine movement varied depending on the coital position; both variations of QUADRUPED, fQUAD1 and fQUAD2, were found to use a significantly greater range of spine motion than fMISS2 (p = 0.017 and p = 0.042, respectively). With the exception of both variations of MISSIONARY, fMISS1 and fMISS2, the majority of the range of motion used was in extension. These findings are most pertinent to patients with LBP that is exacerbated by motions or postures. Based on the spine kinematic profiles of each position, the least-to-most recommended positions for a female flexion-intolerant patient are: fMISS2, fMISS1, fQUAD1, fSIDE, and fQUAD2. These recommendations would be contraindicated for the extension-intolerant patient.
The findings provided here may guide the clinician's specific recommendations, including alternative coital positions and/or movement patterns or suggesting a lumbar support, depending on the female LBP patient's specific motion and posture intolerances.
描述性交过程中女性腰椎的运动和姿势特征，并比较五种常见性交姿势下的这些特征。性交动作和姿势导致的下背痛加剧是女性下背痛（LBP）患者报告的一个普遍问题。为解决这一问题，开展了第一项研究来检查性交过程中的腰椎生物力学。
10名健康男性和女性在以下预先选定的姿势及变体下进行性交：四足位（fQUAD1和fQUAD2，女性分别用肘部和手部支撑上半身）、传教士位（fMISS1和fMISS2，女性分别在臀部和膝盖处最小程度弯曲和更弯曲）以及侧卧位。使用电磁运动捕捉系统测量三维腰椎角度，并将其归一化到最大主动运动范围——发射器和接收器分别固定在骨盆外侧和第十二胸椎棘突上方的皮肤上。为确定每个性交姿势是否具有独特的脊柱运动学特征（即幅度概率分布函数和腰椎运动总范围），使用了单独的单变量一般线性模型，随后进行Tukey的真实显著差异事后分析。性交姿势的呈现是随机的。
女性腰椎运动因性交姿势而异；发现四足位的两种变体fQUAD1和fQUAD2所使用的脊柱运动范围均显著大于fMISS2（分别为p = 0.017和p = 0.042）。除传教士位的两种变体fMISS1和fMISS2外，所使用的大部分运动范围是伸展。这些发现与因运动或姿势而加剧下背痛的患者最为相关。根据每个姿势的脊柱运动学特征，对于不耐受屈曲的女性患者，从最不推荐到最推荐的姿势依次为：fMISS2、fMISS1、fQUAD1、fSIDE和fQUAD2。这些建议对于不耐受伸展的患者是禁忌的。
此处提供的研究结果可为临床医生提供具体建议，包括根据女性下背痛患者特定的运动和姿势不耐受情况，推荐替代性交姿势和/或运动模式，或建议使用腰部支撑。
