Effect of the Hip Flexion Angle on Changes in the Thickness of the Transversus Abdominis during Hip Adduction Exercise

Abstract

[Purpose] This study examined the effect of hip flexion angle on changes in the thickness of the transversus abdominis (TrA) during hip adduction exercise (HAE). [Participants and Methods] HAE was performed by 20 healthy male subjects in the supine position. The HEA was performed under nine conditions, combinations of exercise intensities (rest, light, and moderate) and hip flexion angles (0°, 45°, and 90°). The thicknesses of the TrA, internal oblique and external oblique muscles were evaluated using an ultrasound device. [Results] The thickness of the TrA increased significantly under the moderate/90°condition compared to at rest/90°. During HAE of light intensities, the thickness of the TrA was significantly higher at 90° than at 45°, and during moderate intensities, it was significantly higher at 90° than at 0°and 45°. [Conclusion] The thickness of the TrA in HAE was influenced by the hip flexion angle.