Abstract: Objective To evaluate the reliability of transversus abdominis muscles measure with ultrasonography. Methods The thickness of bilateral transversus abdominis muscles of 20 volunteers at rest and during different postures for training was measured with ultrasonography by 2 examiners. The rate of contraction was calculated. Results The measurement was correlated strongly between examiners (r>0.7). There was significant difference in variety of thickness among postures except head rise to contralateral leg rise (P<0.01). Conclusion Ultrasonography is reliable in measuring transversus abdominis muscles.

Key words: ultrasonography, transversus abdominis muscles, thickness, measurement, reliability