Plantarflexor weakness as a limiting factor of gait speed in stroke subjects and the compensating role of hip flexors
Plantarflexor weakness as a limiting factor of gait speed in stroke subjects and the compensating role of hip flexors
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DOI：
10.1016/s0268-0033(98)00062-x
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发表时间：
1999-02-01
影响因子：
1.8
通讯作者：
Bourbonnais, D
中科院分区：
文献类型：
--
作者：
Nadeau, S;Gravel, D;Bourbonnais, D
目的：利用肌肉利用率（MUR）方法，确定跖屈肌无力是否是影响中风患者快速行走的因素之一。髋屈肌的潜在补偿也被检查。设计：在描述性研究的背景下，选取17名慢性卒中受试者作为方便样本。背景：卒中受试者的步态速度与参与步态的肌肉剩余力量相关。然而，尚未确定这种剩余力量是否限制了步态速度。方法：收集轻侧舒适和最大步态速度的动力学和运动学数据，并用于确定推离阶段足底屈曲力矩（机械需求；MUR分子）。步态时跖屈肌的最大势能力矩（MUR分母）使用由Biodex系统收集的动力学数据导出的方程进行预测。然后在推离期的每1%间隔计算跖屈肌的mri。步态的拉脱阶段和髋屈肌力量也被检查。结果：10例受试者在最大步速下的MUR值在80 ~ 150%之间。这些受试者在跖屈时产生最低的峰值扭矩。该组四名最快的受试者在步态拉离阶段均有较大的髋关节屈曲力矩，并且在测功机上产生较高的髋关节屈曲力矩值。其余7名受试者在以最快速度行走时的MUR值均低于70%。结论：在10例偏瘫患者中，跖屈肌无力应被视为限制步态速度的因素之一。一些跖屈肌弱的受试者可以快速行走，因为他们用髋屈肌进行了补偿。对于其余的中风患者，除跖屈肌无力外，还必须考虑其他因素，以解释其步态速度的降低。
Objective: To determine, using the Muscular Utilization Ratio (MUR) method, whether plantarflexor weakness is among the factors preventing stroke subjects from walking at faster speeds. Potential compensations by the hip flexors were also examined.Design: A convenience sample of 17 chronic stroke subjects in a context of a descriptive study.Background: Gait speed is correlated with the residual strength of the muscles involved in gait in stroke subjects. However, it has not been established if this residual strength limits gait speed.Methods: Kinetic and kinematic data for comfortable and maximal gait speeds were collected on the paretic side, and were used to determine the moments in plantarflexion (mechanical demand; MUR numerator) during the push-off phase. The maximal potential moment (MUR denominator) of the plantarflexors during gait was predicted using an equation derived from dynamometric data collected with a Biodex system. The MURs of the plantarflexors were then calculated at every 1% interval of the push-off phase. The pull-off phase of gait and the hip flexor strength were also examined.Results: Ten subjects of the sample had a MUR value between 80 and 150% at maximal gait speed. These subjects produced the lowest peak torques in plantarflexion. Each of the four fastest subjects of this group had a large hip flexion moment during the pull-off phase of gait and produced high hip flexion torque values on the dynamometer. Each of the seven remaining subjects had a MUR value under 70% when they walked at maximal speed.Conclusions: Weakness of the plantarflexors should be considered as one factor limiting gait speed in 10 hemiparetic subjects. Some subjects with weak plantarflexors could walk rapidly because they compensated with the hip flexors. For the remaining stroke subjects, factors other than weakness of the plantarflexors have to be considered in order to explain the reduction in their gait speed.