Bjerkefors Anna, Ekblom Maria M, Josefsson Karin, Thorstensson Alf
The Swedish School of Sport and Health Sciences (GIH), Biomechanics and Motor Control Laboratory, Box 5626, SE-114 86 Stockholm, Sweden.
Man Ther. 2010 Oct;15(5):502-7. doi: 10.1016/j.math.2010.05.006. Epub 2010 Jun 8.
The deepest muscle of the human ventro-lateral abdominal wall, the Transversus Abdominis (TrA), has been ascribed a specific role in spine stabilization, which has motivated special core stability exercises and hollowing instruction to specifically involve this muscle. The purpose here was to evaluate the levels of activation of the TrA and the superficial Rectus Abdominis (RA) muscles during five common stabilization exercises performed in supine, bridging and four-point kneeling positions, with and without instruction to hollow, i.e. to continuously pull the lower part of the abdomen towards the spine. Nine habitually active women participated and muscle activity was recorded bilaterally from TrA and RA with intramuscular fine-wire electrodes introduced under the guidance of ultrasound. Results showed that subjects were able to selectively increase the activation of the TrA, isolated from the RA, with the specific instruction to hollow and that side differences in the amplitude of TrA activity, related to the asymmetry of the exercises, remained even after the instruction to hollow. The exercises investigated caused levels of TrA activation from 4 to 43% of that during maximal effort and can thus be used clinically to grade the load on the TrA when designing programs aiming at training that muscle.
腹横肌（TrA）是人体腹外侧腹壁最深层的肌肉，它在脊柱稳定中发挥着特定作用，这促使人们开展特殊的核心稳定性训练以及收腹指导，以专门调动这块肌肉。本文旨在评估在仰卧位、桥接位和四点跪位进行的五种常见稳定性训练中，腹横肌和表浅的腹直肌（RA）的激活水平，训练时有无收腹指导，即持续将腹部下部向脊柱方向牵拉。九名习惯性活跃的女性参与了研究，在超声引导下通过肌内细针电极双侧记录腹横肌和腹直肌的肌肉活动。结果显示，受试者能够通过收腹的特定指导，选择性地增强腹横肌的激活，使其与腹直肌分离，并且即使在收腹指导后，与训练不对称性相关的腹横肌活动幅度的侧方差异依然存在。所研究的训练导致腹横肌的激活水平为最大用力时的4%至43%，因此在设计针对该肌肉训练的方案时，这些训练可在临床上用于对腹横肌的负荷进行分级。
