Laboratory for Biomechanics and Biomaterials, Department of Orthopedics, Hannover Medical School, Anna-von-Borries-Str. 1-7, 30625 Hannover, Germany.
J Biomech. 2013 Apr 5;46(6):1201-6. doi: 10.1016/j.jbiomech.2013.02.005. Epub 2013 Mar 6.
The treatment of above-knee amputees with a prosthesis based on a socket is currently considered the standard clinical treatment. Nevertheless there are few investigations on mechanical loading conditions on these devices under realistic circumstances. Further insight in this matter might improve the design of sockets for everyday application. The presented study investigates the loads acting on the socket-interface with a multi-body simulation (MBS). Aim of this study is to validate the quality of the applied MBS next to a direct measurement device. Therefore a custom strain gauge based force-moment sensor is integrated into the conventional socket-based prosthesis of six above-knee amputees. Each subject performs level-walking with kinematic and kinetic data being recorded in a gait laboratory. The data of the marker trajectories is processed in an inverse dynamics MBS where loads at the location of the sensor are determined. The comparison of both methods shows a good agreement of forces and moments and the simulation can be considered fully validated. RMSD is 4.7%BW for the forces and 27.0%BWM for the moments. The model will be used in further research to determine loads on the socket-prosthesis interface of above-knee amputees especially in high risk situations such as falling scenarios, where direct measurement with amputees is not possible for ethical reasons.
目前，基于接受腔的假肢被认为是治疗膝上截肢患者的标准临床治疗方法。然而，对于这些装置在实际情况下的机械加载条件的研究很少。进一步了解这方面的情况可能会改进日常应用中接受腔的设计。本研究通过多体模拟（MBS）研究了作用在接受腔接口上的负载。本研究的目的是验证应用 MBS 的质量，同时使用直接测量设备进行验证。为此，将基于定制应变计的力-力矩传感器集成到六位膝上截肢患者的传统基于接受腔的假肢中。每位受试者在步态实验室中进行平地行走，同时记录运动学和动力学数据。通过逆动力学 MBS 处理标记轨迹的数据，在传感器位置确定负载。两种方法的比较显示出力和力矩的良好一致性，并且可以认为模拟已完全验证。力的均方根误差（RMSD）为 4.7%BW，力矩的 RMSD 为 27.0%BWM。该模型将在进一步的研究中用于确定膝上截肢患者接受腔-假肢接口上的负载，特别是在跌倒等高风险情况下，由于伦理原因，无法对截肢患者进行直接测量。
