Allen Jessica L, Kautz Steven A, Neptune Richard R
Department of Mechanical Engineering, The University of Texas at Austin, TX 78712-1591, USA.
Clin Biomech (Bristol). 2013 Jul;28(6):697-704. doi: 10.1016/j.clinbiomech.2013.06.003. Epub 2013 Jul 2.
Post-stroke subjects with hemiparesis typically utilize a reduced number of modules or co-excited muscles compared to non-impaired controls, with at least one module resembling the merging of two or more non-impaired modules. In non-impaired walking, each module has distinct contributions to important biomechanical functions, and thus different merged module combinations post-stroke may result in different functional consequences.
Three-dimensional forward dynamics simulations were developed for non-impaired controls and two groups of post-stroke hemiparetic subjects with different merged module combinations to analyze how paretic leg muscle contributions to body support, forward propulsion, mediolateral control and leg swing are altered.
The potential of the plantarflexors to generate propulsion was impaired in both hemiparetic groups while the remaining functional consequences differed depending on which modules were merged. Paretic leg swing was impaired during pre-swing when Modules 1 (hip abductors and knee extensors during early stance), and 2 (plantarflexors during late stance) were merged and during late swing when Modules 1 and 4 (hamstrings during late swing into early stance) were merged. When Modules 1 and 4 were merged, body support during early stance was also impaired.
These results suggest that improving plantarflexor ability to generate propulsion is critical during rehabilitation regardless of module composition. If Modules 1 and 2 are merged, then rehabilitation should also focus on improving paretic leg pre-swing whereas if Modules 1 and 4 are merged, then rehabilitation should also focus on improving early stance body support and late paretic leg swing.
与未受损的对照组相比，中风后偏瘫患者通常使用较少的运动模块或共同兴奋的肌肉，其中至少有一个模块类似于两个或更多未受损模块的合并。在正常行走中，每个模块对重要的生物力学功能都有独特的贡献，因此中风后不同的合并模块组合可能会导致不同的功能结果。
针对未受损的对照组以及两组具有不同合并模块组合的中风后偏瘫患者，开展三维正向动力学模拟，以分析患侧腿部肌肉对身体支撑、向前推进、内外侧控制和腿部摆动的贡献是如何改变的。
在两个偏瘫组中，跖屈肌产生推进力的能力均受损，而其余功能结果则因合并的模块不同而有所差异。当模块1（早期站立时的髋外展肌和膝伸肌）和模块2（晚期站立时的跖屈肌）合并时，患侧腿部在摆动前期的摆动受损；当模块1和模块4（从晚期摆动到早期站立时的腘绳肌）合并时，患侧腿部在摆动后期的摆动受损。当模块1和模块4合并时，早期站立时的身体支撑也会受损。
这些结果表明，无论模块组成如何，在康复过程中提高跖屈肌产生推进力的能力至关重要。如果模块1和模块2合并，那么康复还应侧重于改善患侧腿部的摆动前期；而如果模块1和模块4合并，那么康复还应侧重于改善早期站立时的身体支撑以及患侧腿部的摆动后期。
