Zehr E P, Stein R B
Neurophysiology Laboratory, Faculty of Physical Education and Recreation, University of Alberta, Edmonton, Canada.
Prog Neurobiol. 1999 Jun;58(2):185-205. doi: 10.1016/s0301-0082(98)00081-1.
Studies on the reflex modulation of vertebrate locomotion have been conducted in many different laboratories and with many different preparations: for example, lamprey swimming, bird flight, quadrupedal walking in cats and bipedal walking in humans. Emerging concepts are that reflexes are task-, phase- and context-dependent. To function usefully in a behaviour such as locomotion wherein initial conditions change from step to step, reflexes would have to show modulation. Papers are reviewed in which the study of different reflexes have been conducted during different behaviours, with an emphasis on experiments in humans. A framework is developed in which the modulation and flexibility of reflexes are demonstrated. Alterations in cutaneous, and muscle (stretch and load receptor) reflexes between sitting, standing and walking are discussed. Studies in which both electrical, mechanical and 'natural' receptor activation have been conducted during walking are reviewed. Reflexes are shown to have important regulatory functions during human locomotion. A framework for discussion of reflex function throughout the step cycle is developed. The function of a given reflex pathway changes dynamically throughout the locomotor cycle. While all reflexes act in concert to a certain extent, generally cutaneous reflexes act to alter swing limb trajectory to avoid stumbling and falling. Stretch reflexes act to stabilize limb trajectory and assist force production during stance. Load receptor reflexes are shown to have an effect on both stance phase body weight support and step cycle timing. After neurotrauma or in disease, reflexes no longer function as during normal locomotion, but still have the potential to be clinically exploited in gait modification regimens.
例如，七鳃鳗游泳、鸟类飞行、猫的四足行走以及人类的双足行走。新出现的概念是，反射依赖于任务、阶段和环境。在诸如运动这样的行为中，初始条件会逐一步骤发生变化，为了在其中发挥有效作用，反射必须表现出调节作用。本文回顾了在不同行为过程中对不同反射进行研究的论文，重点是人体实验。构建了一个展示反射调节和灵活性的框架。讨论了坐姿、站姿和行走过程中皮肤反射以及肌肉（牵张和负荷感受器）反射的变化。回顾了在行走过程中同时进行电刺激、机械刺激和“自然”感受器激活的研究。结果表明，反射在人类运动过程中具有重要的调节功能。构建了一个在整个步周期讨论反射功能的框架。给定反射通路的功能在整个运动周期中动态变化。虽然所有反射在一定程度上协同作用，但一般来说，皮肤反射的作用是改变摆动肢体轨迹以避免绊倒和摔倒。牵张反射的作用是稳定肢体轨迹并在站立期辅助力量产生。负荷感受器反射被证明对站立期体重支撑和步周期定时都有影响。在神经创伤后或疾病状态下，反射不再像正常运动时那样发挥作用，但仍有在临床步态矫正方案中加以利用的潜力。
