Behavior of human gastrocnemius muscle fascicles during ramped submaximal isometric contractions.
Behavior of human gastrocnemius muscle fascicles during ramped submaximal isometric contractions.
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DOI：
10.14814/phy2.12947
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发表时间：
2016-09
影响因子：
2.5
通讯作者：
Herbert RD
中科院分区：
文献类型：
--
作者：
Héroux ME;Stubbs PW;Herbert RD
对肌肉结构的精确估计对于理解肌肉力学和建立肌肉力学模型是必要的。本研究的主要目的是评估在两个脚踝角度倾斜的足底屈肌收缩过程中，人的腓肠肌的肌束长度和羽状角的连续变化。第二个目的是确定这些变化在近端和远端神经束之间是否不同。15名健康受试者进行倾斜收缩(0-25%MVC)，分别从踝关节90°和120°(角度越大，肌肉长度越短)的腓肠肌内侧(MG，8个部位)和外侧(LG，6个部位)进行超声成像。在所有受试者中，随着扭矩的增加，肌束逐渐变短。MG肌束在90°时缩短5.8 mm(11.1%)，120°时缩短4.5 mm(12.1%)，而LG肌束在两侧踝角缩短5.1 mm(8.8%)。镁羽角在90°时增大1.4°，120°时增大4.9°；LG羽角在90°时减小0.3°，120°时增大2.6°。两个脚踝角度的近侧和远侧肌束的肌肉构筑变化相似。这是第一次描述人类腓肠肌在倾斜等长收缩过程中肌束长度和羽状角的连续变化的研究。近端和远端肌肉区域也发生了非常相似的变化。这些发现与建立主动肌肉力学模型的研究相关。
Precise estimates of muscle architecture are necessary to understand and model muscle mechanics. The primary aim of this study was to estimate continuous changes in fascicle length and pennation angle in human gastrocnemius muscles during ramped plantar flexor contractions at two ankle angles. The secondary aim was to determine whether these changes differ between proximal and distal fascicles. Fifteen healthy subjects performed ramped contractions (0–25% MVC) as ultrasound images were recorded from the medial (MG, eight sites) and lateral (LG, six sites) gastrocnemius muscle with the ankle at 90° and 120° (larger angles correspond to shorter muscle lengths). In all subjects, fascicles progressively shortened with increasing torque. MG fascicles shortened 5.8 mm (11.1%) at 90° and 4.5 mm (12.1%) at 120°, whereas LG muscle fascicles shortened 5.1 mm (8.8%) at both ankle angles. MG pennation angle increased 1.4° at 90° and 4.9° at 120°, and LG pennation angle decreased 0.3° at 90° and increased 2.6° at 120°. Muscle architecture changes were similar in proximal and distal fascicles at both ankle angles. This is the first study to describe continuous changes in fascicle length and pennation angle in the human gastrocnemius muscle during ramped isometric contractions. Very similar changes occurred in proximal and distal muscle regions. These findings are relevant to studies modeling active muscle mechanics.