The ability of dedicated spinal circuits, referred to as central pattern generators (CPGs), to produce the basic rhythm and neural activation patterns underlying locomotion can be demonstrated under specific experimental conditions in reduced animal preparations. The existence of CPGs in humans is a matter of debate. Equally elusive is the contribution of CPGs to normal bipedal locomotion. To address these points, we focus on human studies that utilized spinal cord stimulation or pharmacological neuromodulation to generate rhythmic activity in individuals with spinal cord injury, and on neuromechanical modeling of human locomotion. In the absence of volitional motor control and step-specific sensory feedback, the human lumbar spinal cord can produce rhythmic muscle activation patterns that closely resemble CPG-induced neural activity of the isolated animal spinal cord. In this sense, CPGs in humans can be defined by the activity they produce. During normal locomotion, CPGs could contribute to the activation patterns during specific phases of the step cycle and simplify supraspinal control of step cycle frequency as a feedforward component to achieve a targeted speed. Determining how the human CPGs operate will be essential to advance the theory of neural control of locomotion and develop new locomotor neurorehabilitation paradigms.

在减少的动物准备工作中的特定实验条件下，可以证明专用的脊髓回路（称为中央模式发生器（CPG））产生运动的基本节律和神经激活模式的能力。人类中CPG的存在是一个有争议的问题。同样难以捉摸的是CPG对正常双足运动的贡献。为了解决这些问题，我们专注于利用脊髓刺激或药理神经调节在脊髓损伤个体中产生节律性活动的人体研究，以及人体运动的神经力学模型。在缺乏自主运动控制和特定步骤的感觉反馈的情况下，人类腰脊髓可以产生与CPG诱导的离体动物脊髓神经活动极为相似的节律性肌肉激活模式。从这个意义上讲，人类的CPG可以通过它们产生的活性来定义。在正常的运动过程中，CPG可能在步阶周期的特定阶段有助于激活模式，并简化了步阶周期频率的脊髓上控制，作为前馈组件以实现目标速度。确定人类CPG的运作方式对推进运动神经控制理论和开发新的运动神经康复范例至关重要。CPG可能在步阶周期的特定阶段有助于激活模式，并简化了步阶周期频率的脊柱上控制，作为前馈组件以实现目标速度。确定人类CPG的运作方式对推进运动神经控制理论和开发新的运动神经康复范例至关重要。CPG可能在步阶周期的特定阶段有助于激活模式，并简化了步阶周期频率的脊柱上控制，作为前馈组件以实现目标速度。确定人类CPG的运作方式对推进运动神经控制理论和开发新的运动神经康复范例至关重要。