Rekant Julie, Rothenberger Scott, Chambers April
Bioengineering Department, University of Pittsburgh, Pittsburgh, PA, USA.
Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
Measur Sens. 2022 Oct;23. doi: 10.1016/j.measen.2022.100396. Epub 2022 Aug 7.
Gait analysis can identify injury-risk markers indiscernible to the naked eye. Inertial measurement unit (IMU)-based motion capture circumvents optokinetic motion capture (OMC) clinical implementation barriers with its portability, increased affordability, and decreased computational burden. We compared an IMU system to a robust OMC marker set for gait analysis. 10 healthy adults walked at self-selected speeds equipped with Noraxon MyoMotion IMUs and a 24-marker, 5-cluster marker-set in view of 14 OMC cameras. A single calibration was applied. IMU system and OMC calculated joint angles were compared. A single calibration performed similarly to previously reported repeated calibration. IMU and OMC agreement was best in the sagittal plane with IMU axis-mixing affecting off-sagittal plane agreement. System differences were greater than 5° for most motions. Measurement system bias showed at the ankle and knee, however differences varied across participants. IMU kinematics should be interpreted with caution; consistency and accuracy must improve before IMUs can replace OMC.
步态分析能够识别肉眼难以察觉的损伤风险标志物。基于惯性测量单元（IMU）的运动捕捉技术凭借其便携性、更高的可承受性以及更低的计算负担，克服了光动运动捕捉（OMC）在临床应用中的障碍。我们将一种IMU系统与一套用于步态分析的强大的OMC标记集进行了比较。10名健康成年人以自选速度行走，身上配备了Noraxon MyoMotion IMU以及一套由24个标记点组成的5簇标记集，同时有14台OMC摄像机进行拍摄。进行了一次校准。比较了IMU系统和OMC计算出的关节角度。单次校准的效果与先前报道的重复校准类似。IMU和OMC在矢状面的一致性最佳，IMU轴混合会影响非矢状面的一致性。大多数运动的系统差异大于5°。测量系统偏差出现在踝关节和膝关节处，不过不同参与者之间的差异有所不同。使用IMU运动学数据时应谨慎解读；在IMU能够取代OMC之前，其一致性和准确性必须得到提高。
