Objective: This study aimed to investigate the abdominal muscle activity difference while performing the abdominal bracing technique focusing on inspiration (abdominal bracing group), the general abdominal bracing technique (general bracing group), and the abdominal hollowing technique (abdominal hallowing group) Design: A cross-sectional study design.Methods: Thirty-three healthy participants were recruited for this study. The participants were allocated to 3 different groups; Abdominal bracing group, general bracing group, and abdominal hallowing group. The surface electromyography was placed over the rectus abdominis, external oblique, and internal oblique muscles to collect the activation of abdominal muscles during the trial. Results:The muscle activity of the abdominal bracing group and general bracing groups was significantly higher in all abdominal muscles than in the abdominal hollowing group (p＜0.05) Both rectus abdominis and external oblique muscles showed higher muscle activations in the abdominal bracing group over the general bracing group (p＜0.05). However, the ratio of bilateral external obliques and rectus abdominis to bilateral internal obliques was highest when the hollowing technique was applied (p ＜0.05). Conclusions:The results of study showed the abdominal bracing technique that emphasized inhalation rather than the abdominal hollowing technique or general abdominal bracing technique increased the activity of the abdominal muscles. Therefore, this study is considered to be a data for effective training if the abdominal bracing technique that emphasizes inhalation is applied as a method to increase the activation of the abdominal muscles.

About 23% of the world's population is affected by chronic low back pain, of which 24% to 80% recur within 1 year [1]. Back pain is caused by a variety of factors, including previous back pain, repeated bending and twisting, persistent static posture, anxiety, depression, and somatization [2]. Low back pain arising from the spine, intervertebral disks, or surrounding soft tissues is called mechanical low back pain. This includes lumbosacral muscle strain, lumbar spondylosis, vertebral compression fractures, spondylolisthesis, spondylolysis, and traumatic injury [1].The underlying mechanism of tissue damage that causes LBP may include the accumulation of mechanical loads in specific tissues due to repetitive stresses resulting from repetitive movements or sustained postures in specific directions [3,4]. Therefore, the abnormal flexibility of the muscles acting on the lumbar spine can reduce the change in the direction of the load applied to the lumbar spine, which can be a factor in the onset of low back pain [5].van Wingerden and Vleeming [6] proposed that hamstring tightness in individuals with LBP could be a compensatory mechanism for weak gluteal muscles and