下肢惯性参数对逆向动力学计算的敏感性研究

Sensitivity of Lower Extremity Inertial Parameters in Inverse Dynamic Calculation

文章旨在计算下肢环节惯性参数对逆向动力学计算结果的敏感性。以中国人体环节惯性参数模型为基础,人为地改变下肢环节惯性参数值的范围(±5%和±10%),结合运动学和动力学数据,分别进行逆向动力学计算。结果表明,大腿环节质心位置改变10%对髋关节力矩最大值的影响程度达到-0.49%到0.63%,对应力矩最小值的变化为-24.3%和18.47%;小腿环节质心位置改变10%对膝关节力矩和做功影响均接近0.4%,对较远的髋关节作用影响更弱;无论是大腿还是小腿,环节质量的敏感性要高于环节相对质心位置(P<0.05)。下肢惯性参数改变对逆向动力学计算结果的影响不可忽略,环节惯性参数对动力链较近关节影响最大,环节质量参数的敏感度显著高于环节相对质心位置参数的敏感度。

To investigate the influence of lower extremity inertial parameters on the result of inverse dynamiccalculation. Based on the model of Chinese human body segment inertial parameters and using the data ofkinematics and dynamics, the range of lower extremity inertial parameters （±5% and ±10%） were changedartificially for inverse dynamic calculation. The result shows that 10% change of thigh COM （center of mass）position leads to a change of -0.49% to 0.63% of the maximum torque of hip. The change of the correspondingminimum torque value is -24.3% and 18.47%. 10% change of leg COM position leads to nearly 0.4% of thetorque and work of knee and exerts weaker effect on hip. The sensitivity of segment mass, whether thigh or leg,is more higher than that of the segment COM position （P〈0.05）. The influence of the change of lower limb inertiaparameters on the result of inverse dynamic calculation cannot be ignored. Segment inertial parameters have thegreatest impact on the near joints of the dynamic chain. The sensitivity of segment mass is obviously higher thanthat of segment relative COM position.