Abstract
The purpose of this study was to clarify the influence of posture on lateral abdominal muscles' thickness by using ultrasonography. Twelve male subjects (mean age: 28.6±4.4 years old) were measured for the muscle thicknesses of the external oblique, internal oblique, transversus abdominis and lateral abdominal muscles (the total thickness of three muscles). We measured the thicknesses in the following five postures: supine, sitting and standing postures with neutral pelvic tilt, anterior and posterior pelvic postures in sitting. Then, we compared the muscle thicknesses among the various postures. The muscle thickness of the transversus abdominis and lateral abdominal muscles in sitting and standing postures was significantly greater than in the supine posture. In comparison with the neutral pelvic tilt posture in sitting, all the muscle thicknesses in the posterior pelvic tilt posture were significantly increased. In the anterior pelvic tilt posture, the thickness of the transverses abdominis and lateral abdominal muscles were significantly decreased. Therefore, we should take into consideration the influence of pelvic tilt and antigravity posture when measuring lateral abdominal muscles' thicknesses.
