Below-Knee Amputee Model

Advances in lower limb prostheses have focused on mimicking the lost limb in form and function. However, even if a prosthesis could perfectly mimic the intact limb, an amputee’s gait would have abnormalities due to the change in their musculoskeletal anatomy and the non-ideal interface between the socket of the prosthesis and the residual limb. As a result, the residual limb is loaded in unnatural ways and can result in pain and discomfort which limits the functionality of the prosthesis. Our objective in this project is to develop a forward dynamics musculoskeletal model for simulating amputee gait that can account for an amputee’s unique anatomy and reduce socket loading by directly modeling constraints associated with the socket interface. We hypothesize that problems faced by amputees can be alleviated by using computer modeling and simulation to guide the prosthesis development process towards optimizing the loading conditions and gait efficiency. The expected outcome of this project is a more accurate model for simulating below-knee amputee gait that will form the basis for a new integrated design approach based on OpenSim to optimize the design of lower-limb prostheses. See the associated publication for more detail. The development of this model and related research were supported by a grant from the U.S. National Science Foundation (1526986) and pilot grant from the National Center for Simulation In Rehabilitation Research. <br/><br/>This project includes the following software/data packages: <br/> <ul> <li> <a href="https://simtk.org/frs?group_id=936#pack_2012">Below-Knee Amputee Model </a> : This is a model of a person with a unilateral transtibial amputation, and is adapted from the Gait2354.osim. The ankle, subtalar, and mtp joints were removed on the left side and replaced by a 1-DOF pin joint representing the prosthetic foot PF/DF. The left side tibia and fibula were replaced by a truncated tibia and fibula to represent the residual limb. An additional 6-DOF joint has been added between the residual limb and prosthesis socket segments. All muscles that cross the left ankle were removed except for the medial gastrocnemius, which was truncated and reattached at the middle of the residual limb. </li> </ul>

下肢假肢领域的研究进展集中于对失去的肢体在形态和功能上的模仿。然而，即便假肢能够完美地模仿完整肢体，由于患者骨骼肌肉解剖结构的改变以及假肢套筒与残肢之间的非理想界面，截肢患者的步态仍会存在异常。因此，残肢以不自然的方式承受负荷，可能导致疼痛和不适，从而限制了假肢的功能。本项目的目标是开发一个前向动力学骨骼肌肉模型，用于模拟截肢患者的步态，并能够考虑截肢患者的独特解剖结构，通过直接模拟套筒界面的相关约束条件来减少套筒负荷。我们假设，通过计算机建模和仿真引导假肢开发过程，优化负荷条件和步态效率，可以缓解截肢患者面临的问题。本项目的预期成果是一个更精确的模拟膝关节以下截肢患者步态的模型，该模型将成为基于OpenSim的新集成设计方法的基础，以优化下肢假肢的设计。更多详细信息请参阅相关出版物。本模型及相关研究的开发得到了美国国家科学基金会（项目编号：1526986）和国家康复研究模拟中心试点基金的资助。本项目包括以下软件/数据包：

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<li> <a href="https://simtk.org/frs?group_id=936#pack_2012">膝关节以下截肢模型</a>：这是一个具有单侧胫骨截肢的人体模型，改编自Gait2354.osim。左侧的踝关节、距下关节和跖骨关节被移除，并由一个代表假足PF/DF的1自由度销轴关节所替代。左侧的胫骨和腓骨被截断的胫骨和腓骨所替代，以代表残肢。在残肢和假肢套筒段之间增加了一个额外的6自由度关节。除了内侧腓肠肌外，所有跨越左侧踝关节的肌肉都被移除，该肌肉被截断并重新附着在残肢中部。</li>
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