Biomechanics of Birth-Related Injuries

出生相关伤害的生物力学

• 批准号: 8549844
• 负责人: JOHN O.L. DELANCEY
• 金额: $ 22.32万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8549844
• 关键词: 3-Dimensional; Address; Age-Years; Anterior; Bilateral; Biomechanics; Birth; Birth trauma; Cadaver; Computer Simulation; Data; Development; Elasticity; Elements; Ethics; Exercise; Failure; Female; Funding; Genital system; Head; Health; Histology; Human; Incontinence; Injury; Instruction; Intervention; Isometric Contraction; Knowledge; Lead; Length; Life; Link; Magnetic Resonance; Magnetic Resonance Imaging; Measurement; Measures; Membrane; Methods; Modeling; Morphology; Muscle; Outcome; Pattern; Pelvic Floor Muscle; Pelvic floor dysfunction; Pelvis; Pregnancy; Property; Ptosis; Research; Risk; Risk Factors; Running; Rupture; Scanning; Second Labor Stage; Shapes; Staging; Stereophotogrammetries; Stretching; Structure; Tensile Strength; Testing; Thigh structure; Time; Tissues; Ultrasonography; Vagina; Vaginal delivery procedure; Variant; Woman; Work; arm; base; cost; design; elastography; exhaustion; fetal; improved; insight; instrument; levator ani muscle; modifiable risk; pregnant; prevent; volunteer; women employment

Approximately 15% of women sustain pelvic muscle injuries during vaginal birth, demonstrable through magnetic resonance (MR) imaging. Our geometric model suggests the pelvic floor muscles stretch up to 3.3 times their original length during the second stage of birth. Based on MR imaging, histological, studies, and biomechanical modeling, when injury occurs, we hypothesize an initial rupture of the pubic attachment ofthe pubovisceral muscle (Type 1 injury), in some women followed by an avulsion of the pubic attachment of the arcus tendineus levator ani (Type 2 injury). We seek funds to characterize the variation of tissue in these injury zones and document their failure loads. AIM 1 will characterize the morphology and histology of pubovisceral and arcus tendineus tissues, bi-axial material properties where appropriate, and uniaxial failure properties in 30 cadavers. In 20 volunteers, we will use ultrasound elastography to characterize the effect of pregnancy on perineal body elasticity. AIM 2 will use Aim 1 data to refine a subject-specific, 3-D finite element viscohyperelastic biomechanical model of the second stage of labor from Station +2 on. We will test the above hypotheses with regard to the sequence of Type 1/Type 2 injuries, and run parametric studies to determine the biomechanical factors that increase or decrease the risk of Type 1 and Type 2 injuries. We will validate the model with stereophotogrammetric measurements of perineal descent in 10 laboring women. Since maternal exhaustion is a major risk for instrumented delivery and levator muscle injuries, in AIM 3 we will use a repeated measures design to quantify the outcomes in 40 healthy non-pregnant volunteers between 21 and 30 years of age to study the energetic cost of Valsalva pushing with and without (a) maximal arm and (b) arm and thigh muscle isometric contractions. These observations will yield insights into the factors associated with the greatest risk for injury, and should lead to better methods of preventing these injuries.

大约15%的女性在阴道分娩时骨盆肌肉损伤，这可以通过磁共振（MR）成像证明。我们的几何模型显示，在出生的第二阶段，骨盆底肌肉伸展到原来长度的3.3倍。基于磁共振成像、组织学、研究和生物力学模型，当损伤发生时，我们假设耻骨内脏肌附着体最初破裂（1型损伤），在一些女性中，随后是提肛腱弓附着体撕脱（2型损伤）。我们寻求资金来描述