Blanco-Coloma Laura, García-González Lucía, Sinovas-Alonso Isabel, Torio-Álvarez Silvia, Martos-Hernández Paula, González-Expósito Sara, Gil-Agudo Ángel, Herrera-Valenzuela Diana
Biomechanics and Technical Aids Unit, National Hospital for Paraplegics, Toledo, Spain.
Biorobotics Group, CAR-Centre of Automation and Robotics, CSIC-Spanish National Research Council, Madrid, Spain.
Front Bioeng Biotechnol. 2024 Aug 12;12:1449698. doi: 10.3389/fbioe.2024.1449698. eCollection 2024.
When assessing gait analysis outcomes for clinical use, it is indispensable to use an accurate system ensuring a minimal measurement error. Inertial Measurement Units (IMUs) are a versatile motion capture system to evaluate gait kinematics during out-of-lab activities and technology-assisted rehabilitation therapies. However, IMUs are susceptible to distortions, offset and drifting. Therefore, it is important to have a validated instrumentation and recording protocol to ensure the reliability of the measurements, to differentiate therapy effects from system-induced errors. A protocol was carried out to validate the accuracy of gait kinematic assessment with IMUs based on the similarity of the waveform of concurrent signals captured by this system and by a photogrammetry reference system. A gait database of 32 healthy subjects was registered synchronously with both devices. The validation process involved two steps: 1) a preliminary similarity assessment using the Pearson correlation coefficient, and 2) a similarity assessment in terms of correlation, displacement and gain by estimating the offset between signals, the difference between the registered range of motion (∆ROM), the root mean square error (RMSE) and the interprotocol coefficient of multiple correlation (CMC). Besides, the CMC was recomputed after removing the offset between signals (CMC). The correlation was strong (r > 0.75) for both limbs for hip flexion/extension, hip adduction/abduction, knee flexion/extension and ankle dorsal/plantar flexion. These joint movements were studied in the second part of the analysis. The ∆ROM values obtained were smaller than 6°, being negligible relative to the minimally clinically important difference (MCID) estimated for unaffected limbs, and the RMSE values were under 10°. The offset for hips and ankles in the sagittal plane reached -9° and -8°, respectively, whereas hips adduction/abduction and knees flexion/extension were around 1°. According to the CMC, the kinematic pattern of hip flexion/extension (CMC > 0.90) and adduction/abduction (CMC > 0.75), knee flexion/extension (CMC > 0.95) and ankle dorsi/plantar flexion (CMC > 0.90) were equivalent when captured by each system synchronously. However, after offset correction, only hip flexion/extension (CMC = 1), hip adduction/abduction (CMC > 0.85) and knee flexion/extension (CMC > 0.95) satisfied the conditions to be considered similar.
在评估步态分析结果以供临床使用时，使用一个能确保最小测量误差的精确系统是必不可少的。惯性测量单元（IMU）是一种多功能的运动捕捉系统，用于评估实验室外活动和技术辅助康复治疗期间的步态运动学。然而，IMU容易受到失真、偏移和漂移的影响。因此，拥有一个经过验证的仪器和记录协议对于确保测量的可靠性、区分治疗效果和系统引起的误差非常重要。基于该系统与摄影测量参考系统同时捕获的信号波形的相似性，开展了一项协议来验证使用IMU进行步态运动学评估的准确性。对32名健康受试者的步态数据库与这两种设备进行了同步记录。验证过程包括两个步骤：1）使用皮尔逊相关系数进行初步相似性评估，以及2）通过估计信号之间的偏移、记录的运动范围差异（∆ROM）、均方根误差（RMSE）和多相关协议系数（CMC），在相关性、位移和增益方面进行相似性评估。此外，在去除信号之间的偏移后重新计算CMC（CMC'）。对于髋部屈伸、髋部内收/外展、膝部屈伸和踝部背屈/跖屈，双下肢的相关性都很强（r > 0.75）。这些关节运动在分析的第二部分进行了研究。获得的∆ROM值小于6°，相对于未受影响肢体估计的最小临床重要差异（MCID）可忽略不计，RMSE值低于10°。矢状面中髋部和踝部的偏移分别达到-9°和-8°，而髋部内收/外展和膝部屈伸约为1°。根据CMC，当每个系统同步捕获时，髋部屈伸（CMC > 0.90）和内收/外展（CMC > 0.75）、膝部屈伸（CMC > 0.95）和踝部背屈/跖屈（CMC > 0.90）的运动学模式是等效的。然而，在进行偏移校正后，只有髋部屈伸（CMC = 1）、髋部内收/外展（CMC > 0.85）和膝部屈伸（CMC > 0.95）满足被认为相似的条件。
