Non-rigid modeling of the human musculoskeletal system

软组织有助于减弱冲击力通过身体的传递。然而，大多数人体肌肉骨骼系统的生物力学模型没有考虑软组织的影响。其中一个主要原因是，软组织和骨骼相对于活体对象的运动特征迄今为止在很大程度上没有记载。对活体软组织节段质量的准确估计也非常有限。这降低了任何生物力学模型的准确性，这些模型是为了量化软组织的影响而开发的。因此，将获得对活体受试者的软组织和骨量大小的改进估计（将纳入生物力学模型），用于上肢、下肢和躯干。组织质量预测方程将基于简单的分段人体测量学建立，并根据双光子x射线吸收仪（DXA）获得的分段质量估计进行验证。如果在分析不同年龄和体型的活体受试者的冲击反应时使用个人特定的软硬组织质量估计，则可以实现生物力学模型保真度的显著提高。软组织和刚性组织在冲击后的动态行为将使用粘弹性机械系统进行建模。腿和脚的有限元模型也将被开发和测试，以进行比较。局部肌肉疲劳对冲击后的节段反应和肌肉僵硬的作用将继续进行评估。表面加速度计将提供通过身体各部分和关节传递的力的大小的估计。软组织在减少潜在伤害力传递方面的作用将根据膝关节和肘部等关节的模型输出来确定。节段反应可变性将通过研究反映真实的日常工作和体育活动可能导致受伤的上肢和下肢影响来评估（例如，伸开的手摔倒，跑步时脚跟着地）。

Soft tissues help to attenuate the transmission of impact induced forces through the body.  However, most biomechanical models of the human musculoskeletal system do not consider soft tissue effects.  One main reason for this is that the movement characteristics of soft tissues and bone relative to one another in living subjects are largely undocumented to date.  Accurate estimates of the masses of segment soft tissues for living subjects are also very limited.  This reduces the accuracy of any biomechanical model that is developed to quantify soft tissue effects as a result of impact.  Therefore, improved estimates of soft tissue and bone mass magnitudes in living subjects (to be incorporated in biomechanical models) will be obtained for the upper and lower extremities and trunk.  Tissue mass prediction equations will be developed based on simple segment anthropometrics, and validated against segment mass estimates obtained by Dual Photon X-ray Absorptiometry (DXA).  Considerable gains in biomechanical model fidelity could be realized if person-specific soft and rigid tissue mass estimates were utilized in the analysis of the impact response of living subjects of varying ages and body types.  The dynamic behaviour of the soft and rigid tissues following impact will be modeled using visco-elastic mechanical systems.  A finite element model of the leg and foot will also be developed and tested in comparison.  The role of local muscle fatigue on the segment response and muscle stiffness following impact will continue to be evaluated.  Surface accelerometry will provide estimates of the magnitudes of transmitted forces through body segments and joints.  The effects that soft tissues have on reducing the transmission of potentially injurious forces will be determined based on model outputs at joints such as the knee and elbow.  Segment response variability will be evaluated by studying upper and lower extremity impacts that reflect genuine every day work and sport activities that can result in injury (e.g. falling on an outstretched hand, heel landings during running).