Control mechanisms of simultaneous arm and leg cycling and its training effects in humans

本研究探讨了：（1）是否存在与四足动物相似的中枢模式产生（CPG）系统;（2）控制臂和腿运动的CPG系统在同时进行臂和腿（AL）循环时如何相互作用;（3）在AL循环过程中，CPG系统的相互作用在重复运动任务时发生了多大程度的改变。为了这些目的，AL骑自行车被用作本研究中的运动任务。首先，本研究调查到什么程度intralimb和iterlimb皮肤反射改变，而AL自行车在不同的运动和姿势条件。手臂和腿部肌肉的肌反射和内肢皮肤反射的幅度根据相关肢体的饮水位置进行了显着调制（相位依赖性调制）。在AL细胞周期的同相（相位滞后0）和反相（相位滞后180）期间获得的肢体内和肢体间皮反射幅度的比较没有显著差异。 关于我们 g在坐和站的位置。进行下一项研究以调查在AL循环期间如何协调两个肢体的耦合。10名受试者在没有反馈的情况下以他们喜欢的节奏进行AL骑行10 s，然后被要求自愿改变手臂或腿部骑行的节奏（增加、减少或停止）。腿骑自行车的节奏不受手臂节奏的自愿改变。相比之下，手臂骑自行车的节奏显着改变时，腿部骑自行车的节奏被改变。最后，本研究探讨了如何在AL自行车的手臂上骑自行车腿的主要腰颈部的影响被改变的重复任务（学习效果）。结果发现，训练2 ~ 3天后，对颈椎的影响明显减轻。总之，本研究的结果表明，CPG确实存在inhumans和紧耦合的CPGs在脊髓控制手臂和腿的运动灵活地加强或减弱取决于运动任务的背景。少

The present study investigated, (1) wither there is a central pattern generating (CPG) system similar to that reported in quadruped animals, (2) how the CPG system controlling the arm and leg movement interacts during simultaneous arm and leg (AL) cycling, (3) to what extend the interaction of the CPGs during AL cycling are altered during repetition of the motor task. To these ends, AL cycling was used as the motor task in this study. First, the present study investigated to what extent intralimb and iterlimb cutaneous reflexes are altered while AL cycling under different kinematic and postural conditions. The magnitude of interimb and intralimb cutaneous reflexes in the arm and leg muscles was significantly modulated depending on the drank position for the relevant limb (phase-dependent modulation). There was no significant difference in comparisons of the magnitude of intralimb and interlimb cutaneous reflexes obtained during in-(phase lag 0 ) and anti-phase (phase lag 180 )AL cyclin … More g in sitting and standing positions. The next study was conducted to investigate how coupling of both limbs is coordinated during AL cycling. Ten subjects performed AL cycling at their preferred cadences without feedback for 10 s, and then were asked to voluntarily change the cadence (increase, decrease, or stop) of arm or leg cycling. Leg cycling cadence was not affected by voluntary changess in arm cadence. By contrast, arm cycling cadence was significantly altered when leg cycling cadence was changed. Lastly, the present study investigated how the predominant lumbocervical influence of leg cycling on arm cycling during AL cycling was altered by repetition of the task (learning effect). It was found that the precominant lumbocervical influence was significantly decreased after 2 or 3 days of training. In conclusion, the results of the present study suggest that a CPG does exist inhumans and that tightness of the coupling of the CPGs in the spinal cord controlling arm and leg movement was flexibly strengthened or weakened depending on the context of motor task. Less