Soft tissue artifact causes significant errors in the calculation of joint angles and range of motion at the hip
Soft tissue artifact causes significant errors in the calculation of joint angles and range of motion at the hip
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DOI：
10.1016/j.gaitpost.2017.03.033
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发表时间：
2017-06-01
期刊：
影响因子：
2.4
通讯作者：
Anderson, Andrew E.
中科院分区：
文献类型：
--
作者：
Fiorentino, Niccolo M.;Atkins, Penny R.;Anderson, Andrew E.
反射性皮肤标记物和底层骨骼之间的软组织移动会导致步态分析中的错误。这些错误被称为软组织伪影（STA）。以前的研究没有检查STA如何影响髋关节的角度和活动范围（ROM）在动态活动。在此，我们：1）在行走、髋关节外展和髋关节旋转期间测量骨盆和大腿上皮肤标记的STA，2）跟踪大腿、骨盆和髋关节角度/ROM的量化误差，以及3）确定髋关节自由度的模型约束是否减轻了误差。11名无症状的年轻人同时成像与回射皮肤标记（SM）和双重荧光透视（DF），一种X射线技术与亚毫米和亚度的准确性。STA定义为DF测量的骨解剖框架中SM位置的范围，根据标记位置、活动和受试者而变化。考虑到所有皮肤标记物和活动，平均STA范围为0.3 cm至5.4 cm。STA导致使用SM跟踪的髋关节角度比使用DF跟踪的髋关节多伸展1.9度，多内收0.6度，多内旋5.8度。相对于DF，SM测量的ROM减小，在髋关节旋转过程中关于内外轴的最大差异为21.8度。约束模型并不能始终如一地减少角度误差。我们的研究结果表明，STA造成重大的错误，特别是标记跟踪股骨和髋关节内外旋转。本研究确定了未来研究的必要性，以开发最大限度地减少大腿和骨盆标记物STA的方法。
Soft tissue movement between reflective skin markers and underlying bone induces errors in gait analysis. These errors are known as soft tissue artifact (STA). Prior studies have not examined how STA affects hip joint angles and range of motion (ROM) during dynamic activities. Herein, we: 1) measured STA of skin markers on the pelvis and thigh during walking, hip abduction and hip rotation, 2) quantified errors in tracking the thigh, pelvis and hip joint angles/ROM, and 3) determined whether model constraints on hip joint degrees of freedom mitigated errors. Eleven asymptomatic young adults were imaged simultaneously with retroreflective skin markers (SM) and dual fluoroscopy (DF), an X-ray technique with sub-millimeter and sub-degree accuracy. STA, defined as the range of SM positions in the DF-measured bone anatomical frame, varied based on marker location, activity and subject. Considering all skin markers and activities, mean STA ranged from 0.3 cm to 5.4 cm. STA caused the hip joint angle tracked with SM to be 1.9 degrees more extended, 0.6 degrees more adducted, and 5.8 degrees more internally rotated than the hip tracked with DF. ROM was reduced for SM measurements relative to DF, with the largest difference of 21.8 degrees about the internal-external axis during hip rotation. Constraining the model did not consistently reduce angle errors. Our results indicate STA causes substantial errors, particularly for markers tracking the femur and during hip internal-external rotation. This study establishes the need for future research to develop methods minimizing STA of markers on the thigh and pelvis.