LAUSR

In this study, we examine the thickness of the abdominal muscle and its activity during the performance of the three drawing-in methods. The subjects were 20 healthy male and female students in their 20s. Using ultrasonography and electromyography, the experimenter measured the thickness of the transversus abdominis (TrA) muscle, internal oblique (IO) muscle and external oblique (EO) muscle. The ultrasonography measurements for the drawing-in manoeuver (DI), abdominal bracing, and posterior pelvic tilt (PT) techniques were 0.64±0.20, 0.54±0.15, and 0.46±0.12, respectively, with significant differences for the TrA. The electromyography results of the DI, SA, and PT techniques were 4.35±1.72, 3.00±1.48, and 2.70±1.52, respectively, for the IO. There was a significant difference in the DI, SA, and PT techniques for the EO (5.10±3.30, 3.85±3.89, 2.25±1.29, respectively). The DI method activated the oblique abdominal muscles, but there was no great change in their thickness; the TrA, however, was selectively strengthened through changes in its thickness.