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, 在三个着陆条件中, 52 厘米的条件导致最高峰值最大主、最小主和最大剪切应变。
文献中有有限的体内数据可用于胫骨应变的降落效果。米尔格拉姆et., 报告了从三不同高度 (26、39、52厘米)14到着陆期间从896-1、007µstrain 的最大主应变范围。Ekenman et报告了从45厘米高度13着陆时平均应变2128µstrain。从计算机模拟的最大主要应变在 1,160-1, 410 µstrain 在着陆期间从三个不同的高度 (26, 39, 52 cm), 比米尔格拉姆et . 报告的高, 但低于报告的 Ekenmanet 。13,14
以下原因可能导致当前和以前的研究之间的应变差异。首先, 在这方面和以前的研究中, 存在着人口统计学上的差异。我们用了一个身体活跃的男性题材。Ekenman 的研究涉及女性主题13。米尔格拉姆的研究包括男性和女性, 并报告了平均菌株14。第二, 鞋类可能在骨张力的差异中发挥作用。Lanyon et . 研究了鞋类对胫骨菌株的影响, 他们发现走路和赤脚跑步比穿鞋子的12有更大的张力。目前的研究使用赤脚着陆协议, 计算出的应变值大于米尔格拉姆et 。研究, 用标准运动鞋的着陆协议14。第三, 着陆策略的改变也可能影响胫骨的应变。在本研究中, 可能的主题可能会选择一个策略, 如增加躯干屈曲, 以帮助减少的影响, 当降落高度增加。这个策略可以帮助保护胫骨免受大的压力。米尔格拉姆et还建议了他的主题14使用的可能的保护策略。第四, 在对胫骨应变进行监测的地点可能有轻微的差异。我们的研究检查了胫骨中轴 antero 内侧的骨张力。在米尔格拉姆et 等,菌株是记录从内侧区域的胫骨中部轴14。胫骨下段的矢状平面弯曲力矩可能导致胫骨轴前区附近部位的最大主应变。尽管如此, 我们的应变结果似乎与以前的研究结果相媲美, 并在那些体内研究10,13,14报告的应变范围 (400-2, 200 µstrain) 中下降。
从这种非侵入性方法获得的胫骨应变值受肌肉骨骼模型的准确性的影响。在降落过程中, 对实验的关节角数据和计算机模拟数据进行了交叉相关检验。实验测量数据与计算机仿真数据之间存在较强的相关系数。这表明, 本研究开发的特定主题模型可以合理地复制降落运动。此外, 本研究报告的胫骨菌株远低于3000µstrain, 这证实了从其他研究得出的假设, 胫骨骨形变是线性的在下落着陆期间14,15。因此, 随着计算的应变数据在线性范围内和着陆运动模式的优良复制, 我们得出结论, 从这种非侵入性方法获得的应变数据是合理准确的。此外, 目前的研究只招募了一个主题, 以检查在降落期间的骨应变。未来的研究可以通过使用大样本量来研究降落高度与胫骨骨株之间是否存在剂量反应关系。
本研究的意义在于介绍一种新的无创测量骨变形方法。这种非侵入性的方法解决了与传统的体内应变仪测量相关的局限性, 而这种限制不适用于人体的大量样本。此外, 当前建议的方法还解决了与以前报告的非侵入方法16、17相关的限制, 这是通过使用有限的运动学数据来驱动模拟而受到影响的, 仅适用于研究低地面撞击运动, 如行走。由于胫骨应力性骨折在运动和军事人群中仍然很高, 研究高冲击体力活动 (例如、跑步、跳跃和切割) 对胫骨骨反应的影响至关重要。目前创新的非侵入性方法似乎是进行这些研究的可行办法。这将有助于为运动员和新兵制定适当的体能训练方案, 以减少胫骨应激损伤。此外, 这种创新的非侵入性方法提供了一个机会, 以评估其他骨骼的骨骼菌株无法与实施的测量, 如股骨和舟骨。
有关此无创性骨应变测量的重要问题, 必须在这里解决。首先, 使用 GeBOD 数据库27, 根据个体的年龄、性别、身体质量和身高来创建一个一般的下肢肌肉骨骼模型。实验测量的低体关节中心的空间位置被用来改善肌肉骨骼模型。与一般模型相比, 这个主题特定的建模方法提出了一个更好的肌肉骨骼模型的个人的物理结构。未来的研究可以考虑在多体动力学模拟过程中, 为上肢运动建立全身肌肉骨骼模型。
其次, 模型中每条腿都有45种肌肉。肌肉的起源和插入是解剖上确定的27。采用简单闭环算法对单个肌肉的力产生进行管理。具体而言, 通过逆运动学仿真, 记录了动态运动过程中肌肉长度的变化规律。当正向动态模拟运行时, 将 PID 控制器分配给每个肌肉, 用来调节必要的肌肉力量, 以复制先前记录的肌肉长度历史。这种简单的闭环算法在复制关节运动学方面产生了很好的效果。然而, 这种方法并没有考虑到类似功能的肌肉之间的神经协调, 也不能解释拮抗剂的共同收缩。未来的工程可能会考虑使用一个基于山的肌肉模型, 它由一个主动收缩单元 (CE) 和被动弹性元件 (PE) 组成。基于山的模型将肌肉的力-速度和力长关系结合起来产生张力。计算后的肌肉力可以与肌电图数据进行比较以进行验证。
第三, 从 CT 图像中建立一个特定的胫骨模型, 以反映胫骨骨的真实几何特征。CT 成像是获得胫骨骨真实几何的主要方法, 而磁共振成像 (MRI) 等其他成像技术也可用于制备特定的胫骨模型。此外, 目前的建模协议假定胫骨的物质性质是各向同性的。一般密度值为1.9E-6 千克/厘米3 , 单个杨氏模量为 17 GPa, 分配给所有胫骨 FE 元素。未来的研究可能考虑从胫骨的所有区域获得密度值。这可以通过在 CT 扫描中引入校准的幻像来完成。骨密度可以根据 CT 的 Hounsfield 单位来计算。根据密度数据可以进一步计算骨组织的杨氏模量。通过模拟, 将特定的材料属性分配给胫骨 FE 模型将产生更逼真的骨应变结果。
4、用模态有限元分析法计算骨应变。在这种模态分析中, 频率响应被计算为与膝关节和踝关节施加的机械载荷 (线性和角力) 相匹配。用模态 FE 分析生成由多国部队文件表示的挠性胫骨。这种灵活的胫骨被引入到特定主题的肌肉骨骼模型, 以取代相应的刚性胫骨。在随后的动态模拟中, 灵活的胫骨在每一次步长的变形是量化的。与传统的有限元分析相比, 它计算了一个由成千上万自由度 (数以千计的元素和节点) 组成的 fe 对象在每次运动步骤中的机械响应, 这种模态分析方法处理的数量远远少于频率域内的自由度 (例如, 12 从膝和踝关节加载的条件)。采用模态分析方法, 在典型仿真中, 计算时间从多小时/天减少到小于 1 h。模态分析方法除了消耗较少的计算机时间外, 更适合用于硬结构如骨组织所经历的小变形 (< 10%) 的计算。
最后, 在前面报告的方法16、17上, 当前的非侵入方法的优点必须在这里解决。A) 我们的肌肉骨骼模型被提炼, 以拥有更准确的低体关节中心, 这是通过功能性联合评估22产生的。但是, 以前的方法在使用有限数量的可视标记的帮助下, 基于插件步态过程21定义模型的联合中心。B) 这个模型包含了45个肌肉的每条腿相比, 只有12肌肉使用的前一个模型。在肌肉骨骼模型中增加腿部肌肉的数量会提高模拟的质量。C) 在逆运动学模拟过程中, 肌肉骨骼模型由一组34视觉标记驱动, 放置在下部体上, 从而可以更好地重复实际运动。相比之下, 以前的方法只使用16个标记来驱动相同的模拟, 这可能会引入数值误差的模拟。D) 在正向动态模拟过程中, 将实际地撞击力应用于这种肌肉骨骼模型来模拟运动。然而, 以前的方法无法在模拟中加入地面撞击力。在前向动态模拟中, 如果不使用实际的地面撞击力, 则仅限于研究低冲击活动。以上的步骤, 我们采取改进的忠诚度的主题特定肌肉骨骼模型似乎是成功的检查胫骨变形在人类运动。在模拟中加入真正的地面撞击力证明了在高地面撞击活动中研究骨应变是必要的。
总之,在体内胫骨骨的变形通常用常规的染色量表法来测量。这种方法与诸如侵入性、较少的志愿者、分析的小骨表面积、等) 的局限性有关.本文提出了一种采用模态有限元分析的多体动力学仿真方法, 以在降落过程中量化胫骨的变形。很明显, 这种方法可以解决传统应变计测量中遗留下来的局限性。此外, 由于这种方法可以利用实际的实验运动和动力学数据, 以及一个主题特定的肌肉骨骼模型和灵活的胫骨进行动态模拟和模态有限元分析, 这是一个巨大的改善, 在研究协议在以前报告的方法。因此, 这种非侵入性的方法利用多体动力学模拟的主题特定数据, 结合模态有限元分析, 可以成为研究动态运动过程中胫骨变形的一个很有前途的工具。今后的研究可以利用这种方法研究大鼠骨组织的高冲击活动中的骨张力, 研究骨折的损伤机制。

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动捕获数据所测量的相应关节角进行了比较。用统计分析软件计算了比较的交叉相关系数。交叉相关计算允许10的正向和负方向滞后。每个滞后对应于一个时间步在向前动态模拟 (0.01 s)。确定了最大互相关系数。
对图 2、 图 3和图 4的目视检查显示了与实验数据和模拟数据产生的联合角度之间的相似性。在零滞后 (表 1) 的实验和模拟关节角度之间发现了强的交叉相关系数。
在三不同高度着陆时, 胫骨中段 antero 内侧区域的峰值菌株在表 2中显示。在三着陆高度中, 52 厘米的着陆条件显示最大峰值主、峰值最小主、峰值最大剪切应变。此外, 观察到, 随着下降高度的增加, 峰值最大主应变增加。
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/56759/56759fig1.jpg"> 图 1: 本研究中创建的特定于主题的肌肉骨骼模型.这种下肢肌肉骨骼模型包括六刚性段 (骨盆, 左, 右股骨, 左胫骨, 左和右脚) 和一个灵活的胫骨 (右胫骨)。90腿肌肉连接到模型。为了可视化目的, 每个肌肉都用珊瑚色线表示。联合中心由浅蓝色球代表为右下身体和紫色球为左下身体。<a href="https://cloudflare.jove.com/files/ftp_upload/56759/56759fig1large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/56759/56759fig2.jpg"> 图 2: 在实验性运动捕获数据和模拟数据之间的联合角度比较 (以度为单位), 从26厘米高处降落.实线表示用实验运动捕获数据计算的关节角。虚线表示多体动态模拟数据所产生的关节角。垂直线代表撞击的瞬间。<a href="https://cloudflare.jove.com/files/ftp_upload/56759/56759fig2large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/56759/56759fig3.jpg"> 图 3: 在实验性运动捕获数据和模拟数据之间的联合角度比较 (以度为单位), 从39厘米高处降落.实线表示用实验运动捕获数据计算的关节角。虚线表示多体动态模拟数据所产生的关节角。垂直线代表撞击的瞬间。<a href="https://cloudflare.jove.com/files/ftp_upload/56759/56759fig3large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/56759/56759fig4.jpg"> 图 4: 在实验性运动捕获数据和模拟数据之间的联合角度比较 (以度为单位), 从52厘米高处降落.实线表示用实验运动捕获数据计算的关节角。虚线表示多体动态模拟数据所产生的关节角。垂直线代表撞击的瞬间。<a href="https://cloudflare.jove.com/files/ftp_upload/56759/56759fig4large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always"><tbody>
<tr>
<td></td>
			<td colspan="3">Droplanding 高地</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
<tr>
<td></td>
			<td colspan="2">26厘米</td>
			<td colspan="2">39厘米</td>
			<td colspan="2">52厘米</td>
		</tr>
<tr>
<td>下体关节</td>
			<td>交叉相关系数</td>
			<td>滞后</td>
			<td>交叉相关系数</td>
			<td>滞后</td>
			<td>交叉相关系数</td>
			<td>滞后</td>
		</tr>
<tr>
<td>脚踝</td>
			<td>0.998</td>
			<td>0</td>
			<td>0.998</td>
			<td>0</td>
			<td>0.999</td>
			<td>0</td>
		</tr>
<tr>
<td>膝盖</td>
			<td>1</td>
			<td>0</td>
			<td>1</td>
			<td>0</td>
			<td>1</td>
			<td>0</td>
		</tr>
<tr>
<td>髋关节</td>
			<td>0.999</td>
			<td>0</td>
			<td>1</td>
			<td>0</td>
			<td>1</td>
			<td>0</td>
		</tr>
</tbody></table>表 1: 交叉相关系数和滞后于基于运动捕获数据和由模拟数据产生的关节角产生的关节角的比较.在每个高度的一个试验用于比较。当两种方法之间产生联合角度时, 零滞后表示没有不同的时间。
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always"><tbody>
<tr>
<td></td>
			<td colspan="3">Droplanding 高地</td>
		</tr>
<tr>
<td>骨张力 (µstrain)</td>
			<td>26厘米</td>
			<td>39厘米</td>
			<td>52厘米</td>
		</tr>
<tr>
<td>最大本金</td>
			<td>1160</td>
			<td>1270</td>
			<td>1410</td>
		</tr>
<tr>
<td>最低本金</td>
			<td>-659</td>
			<td>-598</td>
			<td>-867</td>
		</tr>
<tr>
<td>最大剪切</td>
			<td>893</td>
			<td>870</td>
			<td>1140</td>
		</tr>
</tbody></table>表 2: 从三个不同高度降落时胫骨中轴 antero 内侧的胫骨骨菌株.提出了最大主、最小主、最大剪切应变。

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 ...

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Transformations of Stress and Strain

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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 ...

Quantification of Strain in a Porcine Model of Skin Expansion Using Multi-View Stereo and Isogeometric Kinematics

Tissue expansion is a popular technique in plastic and reconstructive surgery that grows skin in vivo for correction of large defects such as burns and giant congenital nevi. Despite its widespread use, planning and executing an expansion protocol is challenging due to the difficulty in measuring the deformation imposed at each inflation step and over the length of the procedure. Quantifying the deformation fields is crucial, as the distribution of stretch over time determines the rate and amount of skin grown at the end of the treatment. In this manuscript, we present a method to study tissue expansion in order to gain quantitative knowledge of the deformations induced during an expansion process. This experimental protocol incorporates multi-view stereo and isogeometric kinematic analysis in a porcine model of tissue expansion. Multi-view stereo allows three-dimensional geometric reconstruction from uncalibrated sequences of images. The isogeometric kinematic analysis uses splines to describe the regional deformations between smooth surfaces with few mesh points. Our protocol has the potential to bridge the gap between basic scientific inquiry regarding the mechanics of skin expansion and the clinical setting. Eventually, we expect that the knowledge gained with our methodology will enable treatment planning using computational simulations of skin deformation in a personalized manner.

This protocol uses multi-view stereo to generate three-dimensional (3D) models out of uncalibrated sequences of photographs, making it affordable and adjustable to a surgical setting. Strain maps between the 3D models are quantified with spline-based isogeometric kinematics, which facilitate representation of smooth surfaces over coarse meshes sharing the same parameterization.

在皮肤扩张使用多视点立体和Isogeometric运动学的猪模型应变的定量

Tissue expansion is a popular technique in plastic and reconstructive surgery that grows skin in vivo for correction of large defects such as burns and ...

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.

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.

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 ...

Biplanar Videoradiography to Study the Wrist and Distal Radioulnar Joints

Accurate measurement of skeletal kinematics in vivo is essential for understanding normal joint function, the influence of pathology, disease progression, and the effects of treatments. Measurement systems that use skin surface markers to infer skeletal motion have provided important insight into normal and pathological kinematics, however, accurate arthrokinematics cannot be attained using these systems, especially during dynamic activities. In the past two decades, biplanar videoradiography (BVR) systems have enabled many researchers to directly study the skeletal kinematics of the joints during activities of daily living. To implement BVR systems for the distal upper extremity, videoradiographs of the distal radius and the hand are acquired from two calibrated X-ray sources while a subject performs a designated task. Three-dimensional (3D) rigid-body positions are computed from the videoradiographs via a best-fit registrations of 3D model projections onto&#160;to each BVR view. The 3D models are density-based image volumes of the specific bone derived from independently acquired computed-tomography data. Utilizing graphics processor units and high-performance computing systems, this model-based tracking approach is shown to be fast and accurate in evaluating the wrist and distal radioulnar joint biomechanics. In this study, we first summarized the previous studies that have established the submillimeter and subdegree agreement of BVR with an in vitro&#160;optical motion capture system in evaluating the wrist and distal radioulnar joint kinematics. Furthermore, we used BVR to compute the center of rotation behavior of the wrist joint, to evaluate the articulation pattern of the components of the implant upon one another, and to assess the dynamic change of ulnar variance during pronosupination of the forearm. In the future, carpal bones may be captured in greater detail with the addition of flat panel X-ray detectors, more X-ray sources (i.e., multiplanar videoradiography), or advanced computer vision algorithms.

Biplanar videoradiography (BVR) is an advanced imaging technique for understanding the three-dimensional movement of skeletal bones and implants. Combining density-based image volumes and videoradiographs of the distal upper extremity, BVR is used to study the in vivo motion of the wrist and distal radioulnar joint, as well as joint arthroplasties.

Accurate measurement of skeletal kinematics in vivo is essential for understanding normal joint function, the influence of pathology, disease progression, ...

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

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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

在皮肤扩张使用多视点立体和Isogeometric运动学的猪模型应变的定量

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

人髋关节微观结构失效机制的成像

Biplanar Videoradiography to Study the Wrist and Distal Radioulnar Joints

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

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