Hodges P W, Richardson C A
Department of Physiotherapy, The University of Queensland, Australia.
Exp Brain Res. 1997 Apr;114(2):362-70. doi: 10.1007/pl00005644.
Because the structure of the spine is inherently unstable, muscle activation is essential for the maintenance of trunk posture and intervertebral control when the limbs are moved. To investigate how the central nervous system deals with this situation the temporal components of the response of the muscles of the trunk were evaluated during rapid limb movement performed in response to a visual stimulus. Fine-wire electromyography (EMG) electrodes were inserted into transversus abdominis (TrA), obliquus internus abdominis (OI) and obliquus externus abdominis (OE) of 15 subjects under the guidance of real-time ultrasound imaging. Surface electrodes were placed over rectus abdominis (RA), lumbar multifidus (MF) and the three parts of deltoid. In a standing position, ten repetitions of shoulder flexion, abduction and extension were performed by the subjects as fast as possible in response to a visual stimulus. The onset of TrA EMG occurred in advance of deltoid irrespective of the movement direction. The time to onset of EMG activity of OI, OE, RA and MF varied with the movement direction, being activated earliest when the prime action of the muscle opposed the reactive forces associated with the specific limb movement. It is postulated that the non-direction-specific contraction of TrA may be related to the control of trunk stability independent of the requirement for direction-specific control of the centre of gravity in relation to the base of support.
由于脊柱结构本身不稳定，在肢体移动时，肌肉激活对于维持躯干姿势和椎间控制至关重要。为了研究中枢神经系统如何应对这种情况，在对视觉刺激做出反应而进行的快速肢体运动过程中，评估了躯干肌肉反应的时间成分。在实时超声成像引导下，将细针肌电图（EMG）电极插入15名受试者的腹横肌（TrA）、腹内斜肌（OI）和腹外斜肌（OE）。将表面电极置于腹直肌（RA）、腰多裂肌（MF）和三角肌的三个部分上。受试者在站立位时，对视觉刺激尽可能快地进行十次肩部前屈、外展和后伸动作。无论运动方向如何，TrA肌电图的起始均早于三角肌。OI、OE、RA和MF肌电图活动的起始时间随运动方向而变化，当肌肉的主要作用与特定肢体运动相关的反作用力相反时，这些肌肉最早被激活。据推测，TrA的非方向特异性收缩可能与躯干稳定性的控制有关，而与相对于支撑基础的重心方向特异性控制要求无关。
