重心移动式步行矫形器后钢缆的生物力学测试

Biomechanical test of the posterior wirerope of Reciprocating Gait Orthosis

目的:探讨重心移动式步行矫形器(RGO)后钢缆的生物力学性能。方法:使用S型拉力传感器测试18位完全性脊髓损伤(SCI)病人配戴RGO行走时对后钢缆的拉力,并用关节角度计测量其行走时的髋关节摆动范围,取其均数作为力学测试的参考值。利用生物力学测试机(MTS858)参照此力学参考值,模拟步行周期对3组18件RGO样品的后钢缆固定螺丝进行疲劳实验,对所得数据进行统计学分析。结果:损伤平面在T4～T12之间的完全性SCI患者在行走时对RGO后钢缆所产生的拉力,随体重的增加而递增,两者之间存在正相关;18例病人的髋关节平均摆动范围是(19.56±1.69)°;3组样品RGO的后钢缆固定螺丝疲劳至断裂的平均次数分别为95450±2636、127171±27194及204620±7148(次),每组断裂次数平均值的上、下限值范围分别为92684<μ<98216、100756<μ<153586和196405<μ<212835,各组之间均有统计学差异(P<0.01)。结论:国产RGO的后钢缆固定螺丝是其相对薄弱环节;体重在55kg以下、55～70kg及70kg以上的SCI患者,在配戴RGO行走分别达到各自相应步数之前,应及时更换其后钢缆的固定螺丝。

Objective： To study the biomechanical characteristics of posterior wirerope of RGO （Reciprocating gait orthosis）. Methods： We used S-type tensile force transducer to test the tensile forces of 18 complete spinal cord injury patients that affected the posterior wirerope of RGO when they walked with the aid of RGO, and measured their range of hip joint motion by joint goniometer. Then we took their average values as reference values. We setted up MTS（Material test system 858）according to the reference values in order to carry out fatigue experiment on the posterior wireropes of 18 RGO samples. Finally, we took the acquired data into statistical analyse. Results： The tensile force of complete spinal cord injury patients with lesion level between T4-T12 on the posterior wirerope of RGO increased by degrees along with the increase of body weight. There was a positive correlation between tensile force and body weight. Their range of hip joint motion was （19.56± 1.69）°. The average values of RGO＇s fatigue circulation of 3 groups were 95450±2636, 127171 ±27194 and 204620 ±7148 respectively, and their ranges of upper and lower values were 92684〈μ〈98216, 100756 〈μ〈153586 and 196405〈μ〈212835 separately. There was statistical differences among each group（P〈0.01）. Conclusions： The posterior wirerope fixed screw of domestic RGO is its weak point. SCI patients of different body weight should replace their posterior wirerope fixed screws after achieving stated paces respectively.