在离心性膝关节伸展过程中，随意激活的特定关节角度依赖性。
Specific joint angle dependency of voluntary activation during eccentric knee extensions.
作者信息
Doguet Valentin, Rivière Valentin, Guével Arnaud, Guilhem Gaël, Chauvet Lucile, Jubeau Marc
机构信息
Laboratory "Movement, Interactions, Performance" (EA 4334), 25 bis Boulevard Guy Mollet, Faculty of Sport Sciences, University of Nantes, 44322, Nantes, France.
French National Institute of Sport (INSEP), Research Department, Laboratory Sport, Expertise and Performance (EA 7370), Paris, France.
出版信息
Muscle Nerve. 2017 Oct;56(4):750-758. doi: 10.1002/mus.25515. Epub 2017 Apr 2.
INTRODUCTION
This study compared voluntary activation during isometric, concentric, and eccentric maximal knee extensions at different joint angles.
METHODS
Fifteen participants performed isometric, concentric, and eccentric protocols (9 contractions each). For each protocol, the central activation ratio (CAR) was randomly measured at 50°, 75°, or 100° of knee joint angle (0° = full knee extension) using superimposed supramaximal paired nerve stimulations during contractions.
RESULTS
CAR increased between 50° and 100° during isometric (93.6 ± 3.1 vs. 98.5 ± 1.4%), concentric (92.4 ± 5.4 vs. 99.2 ± 1.2%), and eccentric (93.0 ± 3.5 vs. 96.6 ± 3.8%) contractions. CAR was lower during eccentric than both isometric and concentric contractions at 75° and 100°, but similar between contraction types at 50°.
CONCLUSIONS
The ability to activate muscle maximally is impaired during eccentric contractions compared with other contraction types at 75° and 100°, but not at 50°. Muscle Nerve 56: 750-758, 2017.
引言
本研究比较了在不同关节角度下等长、向心和离心最大膝关节伸展过程中的自主激活情况。
方法
15名参与者进行了等长、向心和离心方案（各9次收缩）。对于每个方案，在收缩过程中使用叠加的超强配对神经刺激，在膝关节角度50°、75°或100°（0°=膝关节完全伸展）时随机测量中枢激活率（CAR）。
结果
在等长（93.6±3.1%对98.5±1.4%）、向心（92.4±5.4%对99.2±1.2%）和离心（93.0±3.5%对96.6±3.8%）收缩过程中，CAR在50°至100°之间增加。在75°和100°时，离心收缩时的CAR低于等长和向心收缩，但在50°时收缩类型之间相似。
结论
与75°和100°时的其他收缩类型相比，离心收缩过程中最大程度激活肌肉的能力受损，但在50°时不受影响。《肌肉与神经》56: 750 - 758, 2017。
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