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％的女性在阴道出生过程中承受骨盆肌肉损伤，可通过磁共振（MR）成像证明。我们的几何模型表明，在第二阶段，骨盆底肌肉伸展到其原始长度的3.3倍。基于MR成像，组织学，研究和生物力学建模，当发生损伤时，我们假设在某些女性中，耐耐药肌肉的耻骨附着的初始破裂（1型损伤），随后是Arcus tendineus tendineus levator levator ani（2型损伤）的侵蚀。我们寻求资金来表征 这些损伤区域中组织的变化并记录其故障负荷。 AIM 1将以30个尸体中的单轴衰竭特性以及适当的双轴材料特性来表征Pubovisceral和Arcus tendineus组织的形态和组织学。在20名志愿者中，我们将使用超声弹性图来表征怀孕对会周围体内弹性的影响。 AIM 2将使用AIM 1数据来完善主题特异性的3-D有限元粘膜生物力学模型的第二阶段劳动+2的劳动力模型。我们将对1型/类型2型伤害的序列进行上述假设，并进行参数研究，以确定增加或降低1型和2型伤害风险的生物力学因子。我们将通过对10名劳动妇女的立体图测量来验证模型。 由于孕产妇的疲惫是仪器输送和伸肌肌肉损伤的主要风险，因此在AIM 3中，我们将使用重复的措施设计来量化21至30岁之间40名健康的非怀孕志愿者的结果，以研究Valsalva的能量成本，而瓦尔萨尔瓦（Valsalva）的能量成本不断增加，而无需（a）Maximal Arm和（a）Maximal Arm和（B）Arm和（b）Armcle Moss和（b）Armcle iSomple iSomper isottions。 这些观察结果将对与最大伤害风险相关的因素产生见解，并应带来更好的防止这些伤害的方法。