Fluoromicrometry: A Method for Measuring Muscle Length Dynamics with Biplanar Videofluoroscopy
Fluoromicrometry: A Method for Measuring Muscle Length Dynamics with Biplanar Videofluoroscopy
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DOI：
10.1002/jez.2031
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发表时间：
2016-08-01
影响因子：
2.8
通讯作者：
Brainerd, Elizabeth L.
中科院分区：
文献类型：
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作者：
Camp, Ariel L.;Astley, Henry C.;Brainerd, Elizabeth L.
肌肉长度变化的准确测量对于理解肌肉骨骼系统的生物力学至关重要，并且可以提供对肌肉功、力和功率的见解。肌肉长度通常使用声测微法在体内测量，声测微法是一种通过在压电晶体之间发送和接收声音脉冲来测量距离的方法。在这里，我们评估了一种替代方法，荧光显微测量法，该方法通过双平面视频荧光透视跟踪植入的不透射线标记的三维位置来测量肌肉长度随时间的变化。要确定的准确性和精确度的荧光显微镜，我们同时测量的长度变化的一个孤立的肌肉，青蛙缝匠肌，在体外设置使用荧光显微镜和一个cartridge。为了使荧光显微测量法完全匹配荧光显微镜的结果，两个测量值之间的关系应该是线性的，斜率为1。在11次等张收缩中比较了荧光显微镜和电机的肌肉缩短测量值。荧光显微镜的精确度为+/- 0.09 mm，测量为荧光显微镜与肌肉长度回归的均方根误差。荧光显微镜也是准确的：一旦移除了离轴运动，荧光显微镜回归的平均斜率与理想线没有显著差异。因此，荧光显微测量提供了一个有用的替代测量肌肉长度，特别是在活体动物的研究，因为它允许长期标记植入，无线数据收集，并增加空间采样。荧光显微测量还可以与运动形态的X射线重建一起使用，以同时测量肌肉缩短和骨骼运动学，为生物力学研究提供了一种强有力的新工具。(C)2016 Wiley Periodicals，Inc.
Accurate measurements of muscle length changes are essential for understanding the biomechanics of musculoskeletal systems, and can provide insights into muscular work, force, and power. Muscle length has typically been measured in vivo using sonomicrometry, a method that measures distances by sending and receiving sound pulses between piezoelectric crystals. Here, we evaluate an alternative method, fluoromicrometry, which measures muscle length changes over time by tracking the three-dimensional positions of implanted, radio-opaque markers via biplanar videofluoroscopy. To determine the accuracy and precision of fluoromicrometry, we simultaneously measured length changes of an isolated muscle, the frog sartorius, in an in vitro setup using both fluoromicrometry and a servomotor. For fluoromicrometry to perfectly match the results of the servomotor, the relationship between the two measurements should be linear, with a slope of 1. Measurements of muscle shortening from fluoromicrometry and the motor were compared across 11 isotonic contractions. The precision of fluoromicrometry was +/- 0.09 mm, measured as the root mean square error of the regression of fluoromicrometry versus servomotor muscle lengths. Fluoromicrometry was also accurate: the mean slope of the fluoromicrometry-servomotor regressions did not differ significantly from the ideal line once off-axis motion was removed. Thus, fluoromicrometry provides a useful alternative for measuring muscle length, especially in studies of live animals, as it permits long-term marker implantation, wireless data collection, and increased spatial sampling. Fluoromicrometry can also be used with X-Ray Reconstruction of Moving Morphology to simultaneously measure muscle shortening and skeletal kinematics, providing a potent new tool for biomechanics research. (C) 2016 Wiley Periodicals, Inc.