Direct comparison of measured and calculated total knee replacement force envelopes during walking in the presence of normal and abnormal gait patterns.
Direct comparison of measured and calculated total knee replacement force envelopes during walking in the presence of normal and abnormal gait patterns.
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DOI：
10.1016/j.jbiomech.2012.01.015
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发表时间：
2012-04-05
影响因子：
2.4
通讯作者：
Wimmer MA
中科院分区：
文献类型：
--
作者：
Lundberg HJ;Foucher KC;Andriacchi TP;Wimmer MA
从内固定植入物测量的膝关节力为测试预测膝关节力的计算模型的有效性提供了重要信息。本研究的目的是验证一个参数数值模型，预测膝关节接触力对测量从四名受试者与仪器TKR在步态的站立阶段。模型的敏感性异常步态模式进行了研究。结果表明，三名受试者具有相对正常的步态模式，其中平均测量力和计算力之间的差异范围为0.05至0.45体重，并且测量力和计算力（来自三次步行试验）的包络线重叠。第四个主题，谁有一个“四头肌回避”的外部力矩模式，最初有一点重叠之间的测量和计算的力量信封。当添加额外的约束条件时，根据受试者的步态模式进行定制，模型预测得到改善，以完成力包络重叠。多重决定系数分析表明，所有受试者的测量和计算力波形的形状相似（调整后的多重相关系数值在0.88和0.92之间）。参数模型在预测接触力的大小和波形方面是准确的，并且模型预测的准确性受到与正常步态模式的偏差的影响。同样重要的是，解决方案范围产生的力的包络与给定受试者的多个步态试验的相应测量包络基本重叠，这表明体内力产生的可变策略过程被该参数模型的解决方案范围覆盖。
Knee joint forces measured from instrumented implants provide important information for testing the validity of computational models that predict knee joint forces. The purpose of this study was to validate a parametric numerical model for predicting knee joint contact forces against measurements from four subjects with instrumented TKRs during the stance phase of gait. Model sensitivity to abnormal gait patterns was also investigated. The results demonstrated good agreement for three subjects with relatively normal gait patterns, where the difference between the mean measured and calculated forces ranged from 0.05 to 0.45 body weights, and the envelopes of measured and calculated forces (from three walking trials) overlapped. The fourth subject, who had a “quadriceps avoidance” external moment pattern, initially had little overlap between the measured and calculated force envelopes. When additional constraints were added, tailored to the subject’s gait pattern, the model predictions improved to complete force envelope overlap. Coefficient of multiple determination analysis indicated that the shape of the measured and calculated force waveforms were similar for all subjects (adjusted coefficient of multiple correlation values between 0.88 and 0.92). The parametric model was accurate in predicting both the magnitude and waveform of the contact force, and the accuracy of model predictions was affected by deviations from normal gait patterns. Equally important, the envelope of forces generated by the range of solutions substantially overlapped with the corresponding measured envelope from multiple gait trials for a given subject, suggesting that the variable strategic processes of in vivo force generation are covered by the solution range of this parametric model.