Rectus Femoris Knee Muscle Moment Arms Measured in Vivo During Dynamic Motion With Real-Time Magnetic Resonance Imaging
Rectus Femoris Knee Muscle Moment Arms Measured in Vivo During Dynamic Motion With Real-Time Magnetic Resonance Imaging
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DOI：
10.1115/1.4023523
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发表时间：
2013-04-01
影响因子：
1.7
通讯作者：
Blemker, Silvia S.
中科院分区：
文献类型：
--
作者：
Fiorentino, Niccolo M.;Lin, Jonathan S.;Blemker, Silvia S.
力矩臂代表肌肉在给定的肌肉力量下产生关于关节的力矩的能力。这项研究的目标是开发一种使用实时磁共振(MR)成像来测量活体大范围运动中的肌肉力矩手臂的方法。在大口径磁共振(MRI)扫描仪上测量了4例健康受试者膝关节动态屈伸时的股直肌肌腱长度和膝关节角度。用肌腱偏移法通过测量的肌腱长度与关节角度的差值来确定膝部的肌腱力矩臂。一组健康受试者的股直肌力矩臂在膝关节屈曲(平均值：3.0(SD 0.5)cm，最大值：3.5 cm)和伸展(平均值：2.8(SD 0.4)cm，最大值：3.6 cm)过程中的变化相似。这些力矩臂与之前在身体标本上发表的动态肌腱偏移测量结果相比是有利的，但比旋转中心研究中的力矩臂相对较小。本文提出的方法为活体测量肌腱力矩臂提供了一种新的方法，并有可能成为描述动态关节运动中肌肉骨骼几何特征的有力资源。
Moment arms represent a muscle's ability to generate a moment about a joint for a given muscle force. The goal of this study was to develop a method to measure muscle moment arms in vivo over a large range of motion using real-time magnetic resonance (MR) imaging. Rectus femoris muscle-tendon lengths and knee joint angles of healthy subjects (N = 4) were measured during dynamic knee joint flexion and extension in a large-bore magnetic resonance imaging (MRI) scanner. Muscle-tendon moment arms were determined at the knee using the tendon-excursion method by differentiating measured muscle-tendon length with respect to joint angle. Rectus femoris moment arms were averaged across a group of healthy subjects and were found to vary similarly during knee joint flexion (mean: 3.0 (SD 0.5) cm, maximum: 3.5 cm) and extension (mean: 2.8 (SD 0.4) cm, maximum: 3.6 cm). These moment arms compare favorably with previously published dynamic tendon-excursion measurements in cadaveric specimens but were relatively smaller than moment arms from center-of-rotation studies. The method presented here provides a new approach to measure muscle-tendon moment arms in vivo and has the potential to be a powerful resource for characterizing musculoskeletal geometry during dynamic joint motion.