Abstract
This study tried to verify the reliability of lateral abdominal muscles thickness measurement using ultrasonography. In this study, lateral abdominal muscles thickness was measured at different phases of breathing activity to verify the reliability of the measurement. Ten healthy male subjects participated in this study. They were in the sitting position during the measurement. The muscle thickness of the external oblique, internal oblique, and transversus abdominis, and also the total of the muscle thickness (lateral abdominal muscle) were measured under three conditions: quiet breathing (end-expiration and end-inspiration) and maximum expiratory effort. One week later, the subjects were measured again. The differences of muscle thickness among the conditions were compared and calculated for the intraclass correlation coefficient (ICC). During quiet breathing, no significant difference in the thickness of each muscle was found between end-expiration and end-inspiration, and the data for each muscle showed high reliability (ICC=0.87-0.91). On the other hand, during maximum expiratory effort, the thickness of each muscle significantly increased, and the data for each muscle in this case resulted in high values [internal oblique (ICC=0.93), lateral abdominal muscle (ICC=0.91)] and low values [external oblique (ICC=0.48) and transversus abdominis (ICC=0.66)]. High reliability of the measurement was not confirmed during maximum expiratory effort.
