2011 年 23 巻 3 号 p. 357-359
[Purpose] This study was performed to investigate the changes of thickness and reliability of the measurements of lateral abdominal muscles during respiratory maneuvers using ultrasonography. [Subjects and Methods] Participants were 10 healthy male volunteers (26.4±2.7 years old). Ultrasound B-mode scanning was performed with the subjects lying supine and the probe was placed transversely midway between the costal inferior border and the crista iliaca. The muscle thickness of the external oblique (EO), internal oblique (IO), and transverses abdominal (TA) were measured under two conditions: resting expiration (Rex) and maximum expiratory effort (MEE). Percent thickness change was calculated as thickness MME — thickness Rex / thickness Rex×100%. Interclass correlation coefficients (ICC 1, 2) were used to estimate reliability. [Results] Muscle thickness during MME were significantly increased compared with that during Rex and the EO thickness was significantly decreased. Intraexaminer reliability estimates ranged from 0.97 to 0.82 for EO, 0.94 to 0.81 for IO and 0.67 to 0.86 for TA. [Conclusions] We conclude that the thickness of the lateral abdominal muscles is influenced by voluntary respiration, and the assessment of the thickness by means of ultrasonography is adequately reliable. This information may be useful for deciding exercise prescription.