Morito Tsuyoshi, Akuzawa Hiroshi, Okubo Yu, Adachi Gen, Oshikawa Tomoki, Kaneoka Koji
Graduate School of Sports Sciences, Waseda University, Nishitokyo, Tokyo, Japan.
Institute for Human Movement and Medical Science, Niigata University of Health and Welfare, Niigata, Japan.
J Exerc Rehabil. 2022 Aug 26;18(4):264-271. doi: 10.12965/jer.2244254.127. eCollection 2022 Aug.
Draw-in is a promising intervention for regaining isolated control of the transverse abdominis (TrA). Exercises to stimulate isolated contractions are needed; however, the appropriate methods are unclear. The objectives of this study were to examine how the muscle activity and muscle activity ratio of abdominal muscles change with various verbal instructions and to determine the onset of the abdominal muscles during draw-in. The participants were 21 healthy men. TrA electromyography was performed using fine-wire electrodes, and the internal oblique (IO), external oblique (EO), and rectus abdominis (RA) were determined using surface electrodes. The participants performed seven abdominal exercises according to verbal instructions and isolated voluntary contraction of the TrA for more than 5 sec. The TrA showed higher activity in bracing. IO and EO activities were highest in bracing, whereas RA showed the highest activity in maximum bracing. TrA/IO and TrA/EO were not significantly different between conditions. The results of the onset activity analysis of the abdominal muscles during the draw-in maneuver showed that the TrA was significantly earlier than the other muscles. The activity ratios of TrA to IO and EO were highly individualized and did not differ according to the verbal instruction. Maximum draw-in showed more significant IO activity, and bracing showed co-contraction of the superficial and deep abdominal muscles. During draw-in, the TrA initiated the earliest activity among the abdominal muscles and then isolated activity for 1.1 sec.
收腹是一种有望恢复腹横肌（TrA）单独控制能力的干预措施。需要进行刺激单独收缩的练习；然而，合适的方法尚不清楚。本研究的目的是研究腹部肌肉的肌电活动和肌电活动比率如何随各种口头指令而变化，并确定收腹过程中腹部肌肉的起始情况。参与者为21名健康男性。使用细线电极进行腹横肌肌电图检查，使用表面电极确定腹内斜肌（IO）、腹外斜肌（EO）和腹直肌（RA）。参与者根据口头指令进行七项腹部练习，并单独自主收缩腹横肌超过5秒。腹横肌在支撑动作中表现出更高的活动。腹内斜肌和腹外斜肌的活动在支撑动作中最高，而腹直肌在最大支撑动作中表现出最高活动。不同条件下，腹横肌/腹内斜肌和腹横肌/腹外斜肌无显著差异。收腹动作期间腹部肌肉起始活动分析结果表明，腹横肌比其他肌肉显著更早开始活动。腹横肌与腹内斜肌和腹外斜肌的活动比率高度个体化，且不因口头指令而不同。最大收腹时腹内斜肌活动更显著，支撑动作时表现为腹部深浅肌肉的共同收缩。在收腹过程中，腹横肌在腹部肌肉中最早开始活动，然后单独活动1.1秒。
