Name: subject-specific musculoskeletal model for studying bone strain during dynamic motion
Uploaded: 2018-04-11T12:30:00.000+00:00
Duration: 9 min 32 s
Description: Watch this Scientific Journal Video about Subject-specific Musculoskeletal Model for Studying Bone Strain During Dynamic Motion at JoVE.com

陆军部 #W81XWH-08-1-0587, #W81XWH-15-1-0006;球州立大学2010立志补助金。

<ol>
	<li>Brukner, P., Bennell, K., Matheson, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Stress fracture. , (1999).</li><li>Zadpoor, A., Nikooyan, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+relationship+between+lower-extremity+stress+fractures+and+the+ground+reaction+force:+A+systematic+review.">The relationship between lower-extremity stress fractures and the ground reaction force: A systematic review.</a> Clin Biomech. 26, 23-28 (2011).</li><li>Matheson, G. O., Clement, D. B., McKenzie, D. C., Taunton, J. E., Lioyd-Smith, D. R., Maclntyre, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stress+fractures+in+athletes.+A+study+of+320+cases.">Stress fractures in athletes. A study of 320 cases.</a> Am J Sports Med. 15, 46-58 (1987).</li><li>Bennell, K., Grimston, S., Burr, D., Milgrom, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Risk+factors+for+developing+stress+fractures.">Risk factors for developing stress fractures.</a> Musculoskeletal fatigue and stress fractures. , 15-33 (2001).</li><li>Milgrom, C., Giladi, M., Stein, M., Kashtan, H., Margulies, J. Y., Chisin, R., Stenberg, R., Aharonson, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stress+fractures+in+military+recruits.+A+prospective+study+showing+an+unusually+high+incidence.">Stress fractures in military recruits. A prospective study showing an unusually high incidence.</a> J Bone Joint Surg Br. 67, 732-735 (1985).</li><li>Almeida, S. A., Williams, K. M., Shaffer, R. A., Brodine, S. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidemiological+patterns+of+musculoskeletal+injuries+and+physical+training.">Epidemiological patterns of musculoskeletal injuries and physical training.</a> Med Sci Sports Exerc. 31, 1176-1182 (1999).</li><li>Jones, B. H., Knapik, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physical+training+and+exercise-related+injuries,+surveillance,+research+and+injury+prevention+in+military+populations.">Physical training and exercise-related injuries, surveillance, research and injury prevention in military populations.</a> Sports Med. 27, 111-125 (1999).</li><li>Jones, B. H., Thacker, S., Gilchrist, J., Kimsey, C. D., Sosin, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prevention+of+lower+extremity+stress+fractures+in+athletes+and+soldiers:+a+systematic+review.">Prevention of lower extremity stress fractures in athletes and soldiers: a systematic review.</a> Epidemiol Rev. 24, 228-247 (2002).</li><li>Voloshin, A., Wosk, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+in+vivo+study+of+low+back+pain+and+shock+absorption+in+the+human+locomotor+system.">An in vivo study of low back pain and shock absorption in the human locomotor system.</a> J Biomech. 15, 21-27 (1982).</li><li>Burr, D. B., Milgrom, C., Fyhrie, D., Forwood, M., Nyska, M., Finestone, A., Hoshaw, S., Saiag, E., Simkin, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+measurement+of+human+tibial+strains+during+vigorous+activity.">In vivo measurement of human tibial strains during vigorous activity.</a> Bone. 18, 405-410 (1996).</li><li>Ekenman, I., Halvorsen, K., Westblad, P., Fellander-Tsai, L., Rolf, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+reliability+and+validity+of+an+instrumented+staple+system+for+in+vivo+measurement+of+local+bone+deformation.+An+in+vitro+study.">The reliability and validity of an instrumented staple system for in vivo measurement of local bone deformation. An in vitro study.</a> Scand J Med Sci Sports. 8, 172-176 (1998).</li><li>Lanyon, L. E., Hampson, W. G., Goodship, A. E., Shah, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bone+deformation+recorded+in+vivo+from+strain+gauges+attached+to+the+human+tibial+shaft.">Bone deformation recorded in vivo from strain gauges attached to the human tibial shaft.</a> Acta Orthop Scand. 46, 256-268 (1975).</li><li>Ekenman, I., Halvorsen, K., Westblad, P., Tsai, L. F., Rolf, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Local+bone+deformation+at+two+predominant+sites+for+stress+fractures+of+the+tibia:+an+in+vivo+study.">Local bone deformation at two predominant sites for stress fractures of the tibia: an in vivo study.</a> Foot Ankle Int. 19, 479-484 (1998).</li><li>Milgrom, C., Finestone, A., Levi, Y., Simkin, A., Ekenman, I., Mendelson, S., Millgram, M., Nyska, M., Benjuya, N., Burr, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Do+high+impact+exercises+produce+higher+tibial+strains+than+running?.">Do high impact exercises produce higher tibial strains than running?.</a> Br J Sports Med. 34, 195-199 (2000).</li><li>Milgrom, C., Finestone, A., Simkin, A., Ekenman, I., Mendelson, S., Millgram, M., Nyska, M., Larsson, E., Burr, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In-vivo+strain+measurements+to+evaluate+the+strengthening+potential+of+exercises+on+the+tibial+bone.">In-vivo strain measurements to evaluate the strengthening potential of exercises on the tibial bone.</a> J Bone Joint Surg Br. 82, 591-594 (2000).</li><li>Al Nazer, R., Rantalainen, T., Heinonen, A., Sievanen, H., Mikkola, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flexible+multibody+simulation+approach+in+the+analysis+of+tibial+strain+during+walking.">Flexible multibody simulation approach in the analysis of tibial strain during walking.</a> J Biomech. 41, 1036-1043 (2008).</li><li>Al Nazer, R., Klodowski, A., Rantalainen, T., Heinonen, A., Sievanen, H., Mikkola, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+full+body+musculoskeletal+model+based+on+flexible+multibody+simulation+approach+utilised+in+bone+strain+analysis+during+human+locomotion.">A full body musculoskeletal model based on flexible multibody simulation approach utilised in bone strain analysis during human locomotion.</a> Comput Method Biomec. 14, 573-579 (2011).</li><li>Johnson, M. A., Moradi, M. H., Crowe, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> PID control: new identification and design methods. , 543 (2005).</li><li>Craig, R. R., Bampton, M. C. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coupling+of+substructures+for+dynamics+analysis.">Coupling of substructures for dynamics analysis.</a> American Institute of Aeronautics and Astronautics Journal. 6, 1313-1319 (1968).</li><li>Wasfy, T. M., Noor, A. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Computational+strategies+for+flexible+multibody+systems.">Computational strategies for flexible multibody systems.</a> Appl Mech Rev. 56, 553-613 (2003).</li><li>Kadaba, M. P., Ramakrishnan, H. k., Wootten, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+lower+extremity+kinematics+during+level+walking.">Measurement of lower extremity kinematics during level walking.</a> J Orthop Res. 8, 383-392 (1990).</li><li>Schwartz, M. H., Rozumalski, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+method+for+estimating+joint+parameters+from+motion+data.">A new method for estimating joint parameters from motion data.</a> J Biomech. 38, 107-116 (2005).</li><li>Devita, P., Skelly, W. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+landing+stiffness+on+joint+kenetics+and+energetic+in+the+lower+extremity.">Effect of landing stiffness on joint kenetics and energetic in the lower extremity.</a> Med Sci Sports Exerc. 24, 108-115 (1992).</li><li>Dong, X. N., Guo, X. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+dependence+of+transversely+isotropic+elasticity+of+human+femoral+cortical+bone+on+porosity.">The dependence of transversely isotropic elasticity of human femoral cortical bone on porosity.</a> J Biomech. 37, 1281-1287 (2004).</li><li>Schileo, E., Taddei, F., Malandrino, A., Cristofolini, L., Viceconti, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Subject-specific+finite+element+models+can+accurately+predict+strain+levels+in+long+bones.">Subject-specific finite element models can accurately predict strain levels in long bones.</a> J Biomech. 40, 2982-2989 (2007).</li><li>Pattin, C. A., Caler, W. E., Carter, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cyclic+mechanical+property+degradation+during+fatigue+loading+of+cortical+bone.">Cyclic mechanical property degradation during fatigue loading of cortical bone.</a> J Biomech. 29, 69-79 (1996).</li><li>Lifemodeler, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Lifemod Manual. , (2010).</li></ol>

作者声明他们没有竞争的财政利益。

本研究的目的是发展一种非侵入性的方法, 以确定胫骨的变形在高影响活动。对胫骨负荷的影响进行量化, 将有助于更好地理解胫骨应力性骨折。在本研究中, 开发了一个特定于主题的肌肉骨骼模型, 并运行计算机模拟, 以复制在实验室环境中进行的降落运动。研究了降落地高度对胫骨应变的影响。在本研究中, 我们观察到, 随着降落高度的增加, 峰值最大的主要菌株也是如此。此外, 在三个着陆条件?...

骨应激损伤, 如应力性骨折, 是严重的过度使用性损伤, 需要长时间的恢复, 并招致重大医疗费用1,2。应力性骨折在运动和军事人口中都很常见。在所有运动相关的损伤中, 应力性骨折占总3的10%。特别是, 田径运动员在 20%4时面临较高的伤害率。士兵也经历了高压力骨折的发病率。例如, 据报道, 美国陆军的6% 受伤率为1 , 在以色列军队的5中报告了31% 的伤害率。在所有报告的应力性骨折中, 胫骨应力骨折是最常见的一个6,7,8。
运动和体育训练, 有较高的胫骨应力骨折风险通常与高地面影响 (例如, 跳跃, 着陆和切割)。在运动过程中, 当脚接触地面时, 地面撞击力会被应用到身体上。这种撞击力被肌肉骨骼系统和鞋类所消散。骨骼系统作为一系列杠杆, 允许肌肉施加力量来吸收地面撞击9。当腿部肌肉不能充分减少地面撞击时, 下肢骨骼必须吸收残余力。骨结构在这个过程中会经历变形。残余冲击力的重复吸收可能导致骨骼中的 microdamages, 这将积聚并成为应力性骨折。到目前为止, 与外部地面撞击力有关的骨骼反应的信息是有限的。研究胫骨骨在动态运动过程中如何响应高冲击力引入的机械载荷是很重要的。在高撞击活动中检查胫骨骨的变形, 可以更好地了解胫骨应力性骨折的发生机制。
用于测量骨骼变形的常规技术在体内依赖于仪器应变表10,11,12,13,14,15。在骨表面植入应变片需要手术治疗。由于侵入性的性质,在体内研究受志愿者的小样本的限制。此外, 应变计只能监测骨骼表面的一个小区域。本文介绍了一种利用计算机模拟分析骨应变的非侵入性方法1617。这种方法可以将肌肉骨骼模型和计算模拟结合起来, 研究人体运动过程中的骨骼应变。
肌肉骨骼模型由骨骼和骨骼肌肉代表。骨架由骨段组成, 它们是刚性或非变形体。骨骼肌肉被建模为控制器使用渐进积分-导数 (PID) 算法。三期 PID 控制使用估计中的错误来提高输出精度18。从本质上讲, 代表肌肉的 PID 控制器试图通过发展必要的力量来复制身体运动, 从而在一段时间内产生肌肉的长度变化。PID 控制器使用长度/时间曲线中的误差来修改复制运动的力。这个模拟过程创造了一个可行的解决方案, 协调所有的肌肉一起工作, 以移动骨骼和产生身体运动。
肌肉骨骼模型骨架中的一个或多个段可以被建模为柔性体, 以允许测量变形。例如, 胫骨骨可以分解成有限数量的元素, 由数以千计的元素和节点组成。通过有限元分析, 可以研究机械载荷对挠性胫骨的影响。有限元分析计算了各个元素随时间推移的加载响应。随着骨元素和节点数量的增加, 有限元分析的计算时间将显著增加。
为降低计算成本, 并对柔性体的变形进行精确评价, 采用模态有限元分析方法, 在汽车和航天工业中应用了19,20。该过程不是分析单个 FE 元素对时间域内机械载荷的响应, 而是根据频率域中不同的振动频率来评估物体的机械响应。此方法使计算时间大大减少, 同时提供了对变形20的精确测量。虽然模态有限元分析已广泛应用于汽车和航天领域的机械疲劳研究, 但这种方法在人类运动科学中的应用却十分有限。Al Nazer et, 使用一种模态有限元分析, 检查人体步态中的胫骨变形, 并报告令人鼓舞的结果16,17。然而, 只有利用有限的运动学数据进行计算机仿真, 才对其方法产生很大的影响;没有真正的地面撞击力用于辅助模拟。这种方法可能是合理的研究低冲击慢动作, 如步行, 但它不是一个可行的解决方案, 研究高地面撞击运动。因此, 为了检查在动态高影响活动期间的下肢骨反应, 必须开发一种创新的方法来解决与以前报告的方法相关的限制。具体来说, 必须开发一种利用精确的实验运动数据和实际地面冲击力的方法。因此, 本研究的目的是建立一个特定主题的肌肉骨骼模型, 进行多体动力学模拟, 用模态有限元分析, 检查胫骨应变在高冲击活动。选择了由不同高度的降落所表示的动态高冲击运动来测试该方法。

<table><tbody><tr><td>CT Scanner</td><td>GE Medical System</td><td>N/A</td><td>Light Speed VCT. For performing tibia CT scan.</td></tr><tr><td>Motion Capture System</td><td>Vicon Inc</td><td>N/A</td><td>Vicon FX40 high speed cameras. For performing 3D motion capture.</td></tr><tr><td>Force plates</td><td>AMTI Inc</td><td>N/A</td><td>Collecting 3D ground reaction forces</td></tr><tr><td>Vicon Nexus</td><td>Vicon Inc</td><td>N/A</td><td>Motion capture software program. For processing visual marker trajectory data.</td></tr><tr><td>Visual 3D</td><td>C-Motion Inc</td><td>N/A</td><td>Biomechanics analysis software. For computing 3D kinematics and kinetics of human movements.</td></tr><tr><td>MATLAB</td><td>Mathworks Inc</td><td>N/A</td><td>Computer programming software. For performing raw data filtering, data conversion, and data processing.</td></tr><tr><td>ADAMS 2012</td><td>MSC Software Inc</td><td>N/A</td><td>Multibody dynamic computer simulation program.</td></tr><tr><td>LifeMOD</td><td>Lifemodeler Inc</td><td>N/A</td><td>A software Plug-in in ADAMS. For building human body musculo-skeletal models.</td></tr><tr><td>MIMICS 13</td><td>Materialise Inc</td><td>N/A</td><td>Image processing program. A 3D modeling tool to process imaging data. For creating 3D tibia model from CT scans.</td></tr><tr><td>MARC 2012</td><td>MSC Software Inc</td><td>N/A</td><td>Finite element analysis software. For performing volumn meshing, generating tibia FE model, and running modal FE analysis.</td></tr><tr><td>SPSS 19</td><td>IBM Inc</td><td>N/A</td><td>Statistical analysis software.</td></tr></tbody></table>

subject-specific musculoskeletal model for studying bone strain during dynamic motion

骨应激损伤在运动和军事训练中普遍存在。在训练过程中, 重复的大地面撞击力可能是原因。重要的是要确定高地冲击力对下肢骨变形的影响, 以更好地了解骨应激损伤的机制。传统的应变测量方法用于研究体内胫骨变形。这种方法与限制, 包括程序的侵袭性, 少数人类的参与, 和有限的应变数据从小骨表面积。本研究旨在介绍一种新的方法来研究胫骨骨应变在高冲击载荷条件下。一个主题特定的肌肉骨骼模型被创建来代表一个健康的男性 (19 岁, 80 公斤, 1800 毫米)。基于 ct 扫描的对象右胫骨, 建立了一种灵活的有限元胫骨模型。进行了实验室运动捕获, 以获得不同高度 (26、39、52厘米) 降落的运动学和地面反应力。采用多体动态计算机模拟方法, 结合弹性胫骨的模态分析, 对下落着陆时胫骨应变进行量化。计算出的胫骨应变数据与先前的体内研究吻合良好。很明显, 这种非侵入性的方法可以应用于研究大型队列的高冲击活动胫骨骨应变, 这将有助于更好地理解胫骨应力性骨折的损伤机制。

一个健康的高加索男性 (19 岁, 身高1800毫米, 质量80公斤) 自愿为研究。在收集数据之前, 该主题审查并签署了大学机构审查委员会批准的同意表格, 然后才参加研究。这项试验是根据《赫尔辛基宣言》进行的。实验是根据下面的协议进行的。
为了验证正向动态仿真的正确性, 将模拟中的低体关节角与由生物力学分析程序处理的运...

Watch this Scientific Journal Video about Subject-specific Musculoskeletal Model for Studying Bone Strain During Dynamic Motion at JoVE.com

用于研究动态运动期间骨应变的特定主题肌肉骨骼模型 |生物工程|视频

Subject-specific Musculoskeletal Model for Studying Bone Strain During Dynamic Motion

在着陆期间, 下半身的骨骼经历了巨大的机械负荷, 并且变形了。测量骨的变形以更好地了解与撞击有关的骨应激损伤的机制是非常必要的。一种新的方法, 结合学科特定的肌肉骨骼模型和有限元分析是用来测量胫骨应变在动态运动。

动态运动过程中骨应变的学科特异性肌肉模型研究

Bone stress injuries are common in sports and military trainings. Repetitive large ground impact forces during training could be the cause. It is ...

subject-specific-musculoskeletal-model-for-studying-bone-strain

Universidad de Cartagena UDEC

Research

Education

JoVE Journal

JoVE Core

Bioengineering

Biology

Mechanical Engineering

Human Biology

Unit 1

Transformations of Stress and Strain

Musculoskeletal System

SCIENTISTS IN ACTION

9.6K 次观看.  Ball State University. 在着陆期间, 下半身的骨骼经历了巨大的机械负荷, 并且变形了。测量骨的变形以更好地了解与撞击有关的骨应激损伤的机制是非常必要的。一种新的方法, 结合学科特定的肌肉骨骼模型和有限元分析是用来测量胫骨应变在动态运动。

视频: Subject-specific Musculoskeletal Model for Studying Bone Strain During Dynamic Motion

A Coupled Experiment-finite Element Modeling Methodology for Assessing High Strain Rate Mechanical Response of Soft Biomaterials

This study offers a combined experimental and finite element (FE) simulation approach for examining the mechanical behavior of soft biomaterials (e.g. brain, liver, tendon, fat, etc.) when exposed to high strain rates. This study utilized a Split-Hopkinson Pressure Bar (SHPB) to generate strain rates of 100-1,500 sec-1. The SHPB employed a striker bar consisting of a viscoelastic material (polycarbonate). A sample of the biomaterial was obtained shortly postmortem and prepared for SHPB testing. The specimen was interposed between the incident and transmitted bars, and the pneumatic components of the SHPB were activated to drive the striker bar toward the incident bar. The resulting impact generated a compressive stress wave (i.e. incident wave) that traveled through the incident bar. When the compressive stress wave reached the end of the incident bar, a portion continued forward through the sample and transmitted bar (i.e. transmitted wave) while another portion reversed through the incident bar as a tensile wave (i.e. reflected wave). These waves were measured using strain gages mounted on the incident and transmitted bars. The true stress-strain behavior of the sample was determined from equations based on wave propagation and dynamic force equilibrium. The experimental stress-strain response was three dimensional in nature because the specimen bulged. As such, the hydrostatic stress (first invariant) was used to generate the stress-strain response. In order to extract the uniaxial (one-dimensional) mechanical response of the tissue, an iterative coupled optimization was performed using experimental results and Finite Element Analysis (FEA), which contained an Internal State Variable (ISV) material model used for the tissue. The ISV material model used in the FE simulations of the experimental setup was iteratively calibrated (i.e. optimized) to the experimental data such that the experiment and FEA strain gage values and first invariant of stresses were in good agreement.

The current study prescribes a coupled experiment-finite element simulation methodology to obtain the uniaxial dynamic mechanical response of soft biomaterials (brain, liver, tendon, fat, etc.). The multiaxial experimental results that arose because of specimen bulging obtained from Split-Hopkinson Pressure Bar testing were rendered to a uniaxial true stress-strain behavior when simulated through iterative optimization of the finite element analysis of the biomaterial.

一个耦合试验，有限元建模方法以评估生物材料软的高应变率力学响应

This study offers a combined experimental and finite element (FE) simulation approach for examining the mechanical behavior of soft biomaterials (e.g. ...

科研

生物工程

A Method to Estimate Cadaveric Femur Cortical Strains During Fracture Testing Using Digital Image Correlation

This protocol describes the method using digital image correlation to estimate cortical strain from high speed video images of the cadaveric femoral surface obtained from mechanical testing. This optical method requires a texture of many contrasting fiduciary marks on a solid white background for accurate tracking of surface deformation as loading is applied to the specimen. Immediately prior to testing, the surface of interest in the camera view is painted with a water-based white primer and allowed to dry for several minutes. Then, a black paint is speckled carefully over the white background with special consideration for the even size and shape of the droplets. Illumination is carefully designed and set such that there is optimal contrast of these marks while minimizing reflections through the use of filters. Images were obtained through high speed video capture at up to 12,000 frames/s. The key images prior to and including the fracture event are extracted and deformations are estimated between successive frames in carefully sized interrogation windows over a specified region of interest. These deformations are then used to compute surface strain temporally during the fracture test. The strain data is very useful for identifying fracture initiation within the femur, and for eventual validation of proximal femur fracture strength models derived from Quantitative Computed Tomography-based Finite Element Analysis (QCT/FEA).

In this protocol, the femur surface strains are estimated during fracture testing using the digital image correlation technique. The novelty of the method involves application of a high-contrast stochastic speckle pattern on the femur surface, carefully specified illumination, high speed video capture, and digital image correlation analysis for strain calculations.

基于数字图像相关的骨折检测中股骨皮质应变的估算方法

This protocol describes the method using digital image correlation to estimate cortical strain from high speed video images of the cadaveric femoral ...

Biplanar Videoradiography Dataset for Model-based Pose Estimation Development and New User Training

Measuring the motion of the small foot bones is critical for understanding pathological loss of function. Biplanar videoradiography is well-suited to measure in vivo bone motion, but challenges arise when estimating the rotation and translation (pose) of each bone. The bone's pose is typically estimated with marker- or model-based methods. Marker-based methods are highly accurate but uncommon in vivo due to their invasiveness. Model-based methods are more common but are currently less accurate as they rely on user input and lab-specific algorithms. This work presents a rare in vivo dataset of the calcaneus, talus, and tibia poses, as measured with marker-based methods during running and hopping. A method is included to train users to improve their initial guesses into model-based pose estimation software, using marker-based visual feedback. New operators were able to estimate bone poses within 2&#176; of rotation and 1 mm of translation of the marker-based pose, similar to an expert user of the model-based software, and representing a substantial improvement over previously reported inter-operator variability. Further, this dataset can be used to validate other model-based pose estimation software. Ultimately, sharing this dataset will improve the speed and accuracy with which users can measure bone poses from biplanar videoradiography.

<meta charset="utf8"></head><body>用于基于模型的姿态估计开发和新用户培训的双平面视频射线照相数据集

This work presents an in vivo dataset with bone poses estimated with marker-based methods. A method is included here to train operators in improving their initial estimates for model-based pose estimation and reducing inter-operator variability.

用于基于模型的姿态估计开发和新用户培训的双平面视频射线照相数据集

Measuring the motion of the small foot bones is critical for understanding pathological loss of function. Biplanar videoradiography is well-suited to ...

工程学

Imaging of the Microstructural Failure Mechanism in the Human Hip

Imaging the bone microstructure under progressively increasing loads allows for observing the microstructural failure behavior of bone. Here, we describe a protocol for obtaining a sequence of three-dimensional microstructural images of the entire proximal femur under progressively increasing deformation, causing clinically relevant fractures of the femoral neck. The protocol is demonstrated using four femora from female donors aged 66-80 years at the lower end of bone mineral density in the population (T-score range = &#8722;2.09 to &#8722;4.75). A radio-transparent compressive stage was designed for loading the specimens replicating a one-leg stance, while recording the applied load during&#160;micro-computed tomography (micro-CT) imaging. The field of view was 146 mm wide and 132 mm high, and the isotropic pixel size was 0.03 mm. The force increment was based on finite-element predictions of the fracture load. The compressive stage was used to apply the displacement to the specimen and enact the prescribed force increments. Sub-capital fractures due to opening and shear of the femoral neck occurred after four to five load increments. The micro-CT&#160;images and the reaction force measurements were processed to study the bone strain and energy absorption capacity. Instability of the cortex appeared at the early loading steps. The subchondral bone in the femoral head displayed large deformations reaching 16% before&#160;fracture, and a progressive increase in the support capacity up to&#160;fracture. The deformation energy linearly increased with the displacement up to&#160;fracture, while the stiffness decreased to near-zero values immediately before&#160;fracture. Three-fourths of the fracture energy was taken by the specimen during the final 25% force increment. In conclusion, the protocol developed revealed a remarkable energy absorption capacity, or damage tolerance, and a synergic interaction between the cortical and trabecular bone at an advanced donor age.

The protocol enables the measurement of the deformation of the bone microstructure in the entire proximal human femur and its toughness by combining large-volume micro-CT scanning, a custom-made compressive stage, and advanced image processing tools.

人髋关节微观结构失效机制的成像

Imaging the bone microstructure under progressively increasing loads allows for observing the microstructural failure behavior of bone. Here, we describe ...

Four-Dimensional CT Analysis Using Sequential 3D-3D Registration

Four-dimensional computed tomography (4DCT) provides a series of volume data and visualizes joint motions. However, numerical analysis of 4DCT data remains difficult because segmentation in all volumetric frames is time-consuming. We aimed to analyze joint kinematics using a sequential 3D-3D registration technique to provide the kinematics of the moving bone with respect to the fixed bone semiautomatically using 4DCT DICOM data and existing software. Surface data of the source bones are reconstructed from 3DCT. The trimmed surface data are respectively matched with surface data from the first frame in 4DCT. These trimmed surfaces are sequentially matched until the last frame. These processes provide positional information for target bones in all frames of the 4DCT. Once the coordinate systems of the target bones are decided, translation and rotation angles between any two bones can be calculated. This 4DCT analysis offers advantages in kinematic analyses of complex structures such as carpal or tarsal bones. However, fast or large-scale motions cannot be traced because of motion artifacts.

We analyzed joint kinematics from four-dimensional computed tomography data. The sequential 3D-3D registration method semiautomatically provides the kinematics of the moving bone with respect to the subject bone from four-dimensional computed tomography data.

使用顺序 3D-3D 注册进行四维 CT 分析

Four-dimensional computed tomography (4DCT) provides a series of volume data and visualizes joint motions. However, numerical analysis of 4DCT data ...

Biomechanical Testing of Murine Tendons

Tendon disorders are common, affect people of all ages, and are often debilitating. Standard treatments, such as anti-inflammatory drugs, rehabilitation, and surgical repair, often fail. In order to define tendon function and demonstrate efficacy of new treatments, the mechanical properties of tendons from animal models must be accurately determined. Murine animal models are now widely used to study tendon disorders and evaluate novel treatments for tendinopathies; however, determining the mechanical properties of mouse tendons has been challenging. In this study, a new system was developed for tendon mechanical testing that includes 3D-printed fixtures that exactly match the anatomies of the humerus and calcaneus to mechanically test supraspinatus tendons and Achilles tendons, respectively. These fixtures were developed using 3D reconstructions of native bone anatomy, solid modeling, and additive manufacturing. The new approach eliminated artifactual gripping failures (e.g., failure at the growth plate failure rather than in the tendon), decreased overall testing time, and increased reproducibility. Furthermore, this new method is readily adaptable for testing other murine tendons and tendons from other animals.

The protocol describes efficient and reproducible tensile biomechanical testing methods for murine tendons through the use of custom-fit 3D printed fixtures.

鼠头的生物力学试验

Tendon disorders are common, affect people of all ages, and are often debilitating. Standard treatments, such as anti-inflammatory drugs, rehabilitation, ...

A Minimally Invasive Model to Analyze Endochondral Fracture Healing in Mice Under Standardized Biomechanical Conditions

Bone healing models are necessary to analyze the complex mechanisms of fracture healing to improve clinical fracture treatment. During the last decade, an increased use of mouse models in orthopedic research was noted, most probably because mouse models offer a large number of genetically-modified strains and special antibodies for the analysis of molecular mechanisms of fracture healing. To control the biomechanical conditions, well-characterized osteosynthesis techniques are mandatory, also in mice. Here, we report on the design and use of a closed bone healing model to stabilize femur fractures in mice. The intramedullary screw, made of medical-grade stainless steel, provides through fracture compression an axial and rotational stability compared to the mostly used simple intramedullary pins, which show a complete lack of axial and rotational stability. The stability achieved by the intramedullary screw allows the analysis of endochondral healing. A large amount of callus tissue, received after stabilization with the screw, offers ideal conditions to harvest tissue for biochemical and molecular analyses. A further advantage of the use of the screw is the fact that the screw can be inserted into the femur with a minimally invasive technique without inducing damage to the soft tissue. In conclusion, the screw is a unique implant that can ideally be used in closed fracture healing models offering standardized biomechanical conditions.

This protocol describes a minimally invasive osteosynthesis technique using an intramedullary screw for standardized stabilization of femur fractures, which can be used to analyze endochondral bone healing in mice.

标准化生物力学条件下小鼠软骨骨折愈合的微创模型分析

Bone healing models are necessary to analyze the complex mechanisms of fracture healing to improve clinical fracture treatment. During the last decade, an ...

医学

骨折易感性机械测试的原则和方案

Practical Considerations for the Design, Execution, and Interpretation of Studies Involving Whole-Bone Bending Tests of Rodent Bones

Skeletal fragility leading to fracture is an American public health crisis resulting in 1.5 million fractures each year and $18 billion in direct care costs. The ability to understand the mechanisms underlying bone disease and the response to treatment is not only desired, but critical. Mechanical testing of bone serves as a valuable technique for understanding and quantifying a bone&#39;s susceptibility to fracture. While this method appears simple to perform, inappropriate and inaccurate conclusions may be reached if governing assumptions and key steps are disregarded by the user. This has been observed across disciplines as studies continue to be published with misuse of methods and incorrect interpretation of results. This protocol will serve as a primer for the principles associated with mechanical testing along with the application of these techniques-from considerations of sample size through tissue harvesting and storage, to data analysis and interpretation. With this in hand, valuable information regarding a bone&#39;s susceptibility to fracture may be obtained, furthering understanding for both academic research and clinical solutions.

作者聚焦：提高全骨弯曲测试的准确性和可重复性 

Mechanical testing of rodent bones is a valuable method for extracting information regarding a bone's susceptibility to fracture. Lacking proper practical understanding, the results may be overinterpreted or lack validity. This protocol will serve as a guide to ensure mechanical tests are performed accurately to provide valid and functional data.

设计、执行和解释涉及啮齿动物骨骼全骨弯曲试验的研究的实际考虑因素

Skeletal fragility leading to fracture is an American public health crisis resulting in 1.5 million fractures each year and $18 billion in direct care ...

动态运动过程中骨应变的学科特异性肌肉模型研究

摘要

探索更多视频

此视频中的章节

一个耦合试验，有限元建模方法以评估生物材料软的高应变率力学响应

基于数字图像相关的骨折检测中股骨皮质应变的估算方法

用于基于模型的姿态估计开发和新用户培训的双平面视频射线照相数据集

用于基于模型的姿态估计开发和新用户培训的双平面视频射线照相数据集

人髋关节微观结构失效机制的成像

使用顺序 3D-3D 注册进行四维 CT 分析

鼠头的生物力学试验

标准化生物力学条件下小鼠软骨骨折愈合的微创模型分析

设计、执行和解释涉及啮齿动物骨骼全骨弯曲试验的研究的实际考虑因素

设计、执行和解释涉及啮齿动物骨骼全骨弯曲试验的研究的实际考虑因素