Kostyukov Alexander I, Gorkovenko Andriy V, Kulyk Yurii A, Lehedza Oleksii V, Shushuiev Dmytro I, Zasada Mariusz, Strafun Serhii S
Department of Movement Physiology, Bogomoletz Institute of Physiology, National Academy of Sciences, Kyiv, Ukraine.
Department of Physical Education, Gdansk University of Physical Education and Sport, Gdansk, Poland.
Front Physiol. 2022 May 19;13:864404. doi: 10.3389/fphys.2022.864404. eCollection 2022.
This study examines some of the non-linear effects of signal transduction in the human motor system, with particular emphasis on muscle hysteresis. The movement tests were analyzed in a group of eight subjects, which were asked to develop tangential force using visual biofeedback while performing slow, externally imposed, circular movements of right hand holding a moving handle operated by a computerized mechatronic system. The positional changes in the averaged EMGs of the elbow and shoulder muscles were compared for all combinations of direction of movement and generated force. Additionally, for one of the subjects, there was carried out MRI identification and 3D printing of the bones of the forelimb, shoulder, scapula and collarbone, which made it possible to reconstruct for him the length and force traces of all the muscles under study. The averaged EMG traces in muscles of both joints show their close correspondence to the related force traces, however, the co-activation patterns of activity in agonists and antagonists were also often encountered. The EMG waves related to the respective force waves were strongly dependent on the predominant direction of the muscle length changes within the correspondent force wave locations: the EMG intensities were higher for the shortening muscle movements ( contractions) and lower during muscle lengthening ( contractions). The data obtained allows to suggest that for two-joint movements of the forelimbs, it is sufficient to consider the and (patterns of simultaneous activity in different muscles), ignoring at the first stage the effects associated with . On the other hand, the data obtained indicate that the movement kinematics has a strong modulating effect on the , dividing it into and subtypes, in accordance with the known non-linear features of the muscle dynamics. It has been shown that the and differences in the responses of the shoulder muscles are more clearly distinguishable than those in the elbow muscles. The shoulder muscles also have a more pronounced symmetry of the averaged EMG responses with respect to the ascending and descending phases of force waves, while demonstrating a lower degree of antagonist cocontraction. The data obtained suggest that the central commands in two-joint movements are determined mainly by the interdependence of and including both intra- and inter-joint components, while can be interpreted as a potent modulator of .
本研究考察了人类运动系统中信号转导的一些非线性效应，尤其着重于肌肉滞后现象。对一组八名受试者的运动测试进行了分析，要求他们在使用视觉生物反馈的情况下，通过右手握住由计算机化机电系统操作的移动手柄进行缓慢的、外部施加的圆周运动来产生切向力。针对运动方向和产生的力的所有组合，比较了肘部和肩部肌肉平均肌电图的位置变化。此外，对其中一名受试者进行了前肢、肩部、肩胛骨和锁骨骨骼的磁共振成像识别及三维打印，从而能够为他重建所有被研究肌肉的长度和力的轨迹。两个关节肌肉的平均肌电图轨迹显示它们与相关的力的轨迹密切对应，然而，也经常遇到主动肌和拮抗肌活动的共同激活模式。与各自力波相关的肌电图波强烈依赖于相应力波位置内肌肉长度变化的主要方向：肌肉缩短运动（收缩）时肌电图强度较高，而肌肉拉长（收缩）时较低。所获得的数据表明，对于前肢的双关节运动，在第一阶段忽略与 相关的效应，考虑 和 （不同肌肉同时活动的模式）就足够了。另一方面，所获得的数据表明运动运动学对 有很强的调节作用，根据肌肉动力学已知的非线性特征将其分为 和 亚型。已经表明，肩部肌肉反应中的 和 差异比肘部肌肉中的更明显。肩部肌肉在力波的上升和下降阶段的平均肌电图反应也具有更明显的对称性，同时拮抗肌共同收缩程度较低。所获得的数据表明，双关节运动中的中枢指令主要由 和 的相互依赖决定，包括关节内和关节间成分，而 可被解释为 的有效调节因子。
