Changes in lateral abdominal muscle thickness during an abdominal drawing-in maneuver in individuals with and without low back pain.

The purpose of this study was to compare lateral abdominal muscle thickness changes in individuals with and without low back pain (LBP) during an abdominal drawing-in maneuver (ADIM) using ultrasound imaging. Twenty individuals (13 females and 7 males, average age 40.1 ± 13.4) with stabilization classification LBP and 19 controls (10 females and 9 males, average age 30.3 ± 8.7) participated in this study. Bilateral measurements were made using ultrasound imaging to determine changes in thickness of the transversus abdominus (TrA) and external and internal oblique (EO+IO) muscles during an ADIM. There were no significant differences in relaxed muscle thickness values or contraction ratios for the TrA or EO+IO between groups or side. Individuals with stabilization classification LBP demonstrated no difference in lateral abdominal muscle thickness during an ADIM when compared with controls without LBP when using a pressure biofeedback device to monitor stability.