Dias Caroline P, Freire Bruno, Goulart Natália B A, Onzi Eduardo S, Becker Jefferson, Gomes Irenio, Arampatzis Adamantios, Vaz Marco A
a Exercise Research Laboratory , School of Physical Education, Federal University of Rio Grande do Sul , Porto Alegre , Brazil.
b Physical Education Course, Faculty of Serra Gaúcha , Caxias do Sul , Brazil.
Top Stroke Rehabil. 2017 Apr;24(3):206-213. doi: 10.1080/10749357.2016.1210873. Epub 2016 Jul 22.
Spasticity poststroke leads to muscle weakness and soft tissue contracture, however, it is not clear how muscle properties change due this motor neural disorder. The purpose was to compare medial gastrocnemius muscle architecture and mechanical properties of the plantarflexor muscles between stroke survivors with spasticity and healthy subjects.
The study included 15 stroke survivors with ankle spasticity and 15 healthy subjects. An isokinetic dynamometer was used for the evaluation of maximal isometric plantarflexor torque and images of the medial gastrocnemius muscle were obtained using ultrasonography. Images were collected at rest and during a maximum voluntary contraction.
The affected limb showed reduced fascicle excursion (0.9 ± 0.7 cm), shorter fascicle length, and reduced muscle thickness (0.095 ± 0.010% of leg length and 1.18 ± 0.20 cm, at rest) compared to contralateral (1.6 ± 0.4 cm, 0.106 ± 0.015% of leg length and 1.29 ± 0.24 cm, respectively) and to healthy participants (1.8 ± 0.7 cm, 0.121 ± 0.019% of leg length and 1.43 ± 0.22 cm, respectively). The contralateral limb showed lower force (between 32 and 40%) and similar architecture parameters compared to healthy participants.
The affected limb had a different muscle architecture that appears to result in lower force production. The contralateral limb showed a decrease in force compared to healthy participants due to the other neural impairments than muscle morphology. Spasticity likely leds to adaptations of muscle architecture in the affected limb and in force reductions in both limbs of stroke survivors.
中风后痉挛会导致肌肉无力和软组织挛缩，然而，目前尚不清楚这种运动神经障碍如何改变肌肉特性。本研究旨在比较患有痉挛的中风幸存者与健康受试者之间腓肠肌内侧的肌肉结构以及跖屈肌的力学特性。
本研究纳入了15名患有踝关节痉挛的中风幸存者和15名健康受试者。使用等速测力计评估最大等长跖屈扭矩，并通过超声检查获取腓肠肌内侧的图像。在静息状态和最大自主收缩期间采集图像。
与对侧肢体（分别为1.6±0.4厘米、腿长的0.106±0.015%和1.29±0.24厘米）以及健康参与者（分别为1.8±0.7厘米、腿长的0.121±0.019%和1.43±0.22厘米）相比，患侧肢体的肌束位移减小（0.9±0.7厘米），肌束长度缩短，肌肉厚度减小（静息时为腿长的0.095±0.010%和1.18±0.20厘米）。与健康参与者相比，对侧肢体的力量较低（在32%至40%之间），但其结构参数相似。
患侧肢体具有不同的肌肉结构，这似乎导致了力量产生降低。与健康参与者相比，对侧肢体由于肌肉形态以外的其他神经损伤而导致力量下降。痉挛可能导致中风幸存者患侧肢体的肌肉结构发生适应性变化，并导致双侧肢体力量降低。
