Altered ultrasonographic activity of abdominal muscles during breathing in males with and without nonspecific chronic low back pain.

Purpose This study aimed to investigate the altered ultrasonographic activity of abdominal muscles during breathing in males with and without nonspecific chronic low back pain (NSCLBP). Design Cross-sectional study. Methods Twenty males with NSCLBP and 20 males without NSCLBP were recruited. Muscle thickness change was measured by ultrasonography during breathing in the end-inspiration and end-expiration phases for the transverse abdominis (TrA), internal oblique (IO), external oblique (EO), and rectus abdominis (RA) muscles. The data were normalized to the end-inspiration thickness. An independent t test was run to analyze the data at a confidence level of 95% (p Results The participants with NSCLBP had thicker IO muscles in the end-inspiration (p = 0.030) and end-expiration (p = 0.017) phases as well as greater RA (p = 0.006) and smaller EO (p = 0.003) normalized thickness changes during breathing. Conclusion The normalized thickness changes during breathing differed between the participants with and without NSCLBP. Reduced EO and increased RA activity may predispose the spine to further injuries. Therefore, normalizing the breathing pattern should be considered in the management of people with NSCLBP.