Department of Rehabilitation Medicine, Research Institute MOVE, VU University Medical Center, Amsterdam, The Netherlands.
Med Biol Eng Comput. 2013 Apr;51(4):377-86. doi: 10.1007/s11517-012-1006-5. Epub 2012 Dec 9.
3D kinematic measurements in children with cerebral palsy (CP) to assess gait deviations can only be performed in gait laboratories using optoelectronic systems. Alternatively, an inertial and magnetic measurement system (IMMS) can be applied for ambulatory motion-tracking. A protocol named Outwalk has recently been developed to measure the 3D kinematics during gait with IMMS. This study preliminary validated the application of IMMS, based on the Outwalk protocol, in gait analysis of six children with CP and one typically developing child. Reference joint kinematics were simultaneously obtained from a laboratory-based system and protocol. On average, the root mean square error (RMSE) of Outwalk/IMMS, compared to the reference, was less than 17° in the transversal plane, and less than 10° in the sagittal and frontal planes. The greatest differences were found in offsets in the knee and ankle rotation, and in the hip flexion. These offset differences were mainly caused by a different anatomical calibration in the protocols. When removing the offsets, RMSE was always less than 4°. Therefore, IMMS is suitable for gait analysis of major joint angles in a laboratory-free setting. Further studies should focus on improvement of anatomical calibrations of IMMS that can be performed in children with CP.
在步态实验室中使用光电系统对脑瘫（CP）儿童进行三维运动学测量以评估步态偏差，这是唯一的方法。或者，可以应用惯性和磁测量系统（IMMS）进行动态运动跟踪。最近开发了一种名为“Outwalk”的方案，用于通过 IMMS 测量步态期间的三维运动学。本研究初步验证了基于“Outwalk”方案的 IMMS 在 6 名 CP 儿童和 1 名典型发育儿童的步态分析中的应用。参考关节运动学同时从基于实验室的系统和方案中获得。平均而言，与参考值相比，“Outwalk/IMMS”的均方根误差（RMSE）在横平面上小于 17°，在矢状面和额状面小于 10°。最大的差异出现在膝关节和踝关节旋转以及髋关节屈曲的偏移。这些偏移差异主要是由于方案中的不同解剖校准引起的。当去除偏移时，RMSE 始终小于 4°。因此，IMMS 适用于无实验室环境下主要关节角度的步态分析。进一步的研究应侧重于改进 CP 儿童可进行的 IMMS 的解剖校准。
