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

本研究探讨了(1)是否存在与已报道的四足动物类似的中枢模式生成(CPG)系统，(2)控制手臂和腿部运动的CPG系统在同时骑行手臂和腿(AL)时如何相互作用，(3)在重复运动任务的过程中，在AL骑行过程中CPG之间的相互作用发生了多大程度的改变。为此，本研究使用AL自行车作为运动任务。首先，本研究调查了在不同的运动学和姿势条件下，AL骑行时肢体内和四肢皮肤反射的改变程度。手臂和腿部肌肉的肢体间和肢体内皮肤反射的大小明显取决于相关肢体的饮酒位置(相位依赖调制)。在比较同相(相位滞后0)和反相位(相位滞后180)AL Cyclin…时，肢体内和肢体间皮肤反射的大小没有显著差异坐姿和站姿的g更高。下一项研究是为了研究AL自行车过程中两个肢体的耦合是如何协调的。10名受试者在没有反馈的情况下以自己喜欢的节奏进行AL自行车10次S，然后被要求自愿改变手臂或腿部自行车的节奏(增加、减少或停止)。腿部骑行节奏不受手臂节奏随意变化的影响。相比之下，当腿部自行车节奏改变时，手臂自行车节奏显著改变。最后，本研究调查了在AL自行车中腿部自行车对手臂自行车的主要腰颈影响是如何通过任务的重复(学习效果)而改变的。结果发现，经过2~3天的训练后，前驱对腰颈的影响明显减小。综上所述，本研究的结果表明，在人类中确实存在CPG，并且CPG在控制手臂和腿部运动的脊髓中的耦合的紧密性根据运动任务的背景而灵活地增强或减弱。较少

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