Evaluation of Abdominal Muscle Thickness Changes During Abdominal Hollowing Maneuver in Different Positions Using a Sphygmomanometer for People With Chronic Low Back Pain.

Objective: The aim of this present investigation was to compare changes in transverse abdominis (TrA) thickness in a functional position with those in a less functional but more supportive posture and to determine which posture showed greater changes in TrA thickness between rest and during abdominal drawing-in maneuver (ADIM) relative to external oblique (EO) and internal oblique (IO) muscles. Methods: Thirty adult participants with chronic low back pain were included in this observational study. The abdominal muscle thickness was measured in the supine, crook lying, prone, quadruped, sitting, side bridge, and standing poitions on a tilt board using ultrasonography. The mean of abdominal muscle thickness changes was measured during ADIM, and a sphygmomanometer was used in the supine position under the lumbar spine and in the prone position under the abdominal wall. Transverse abdominis, EO, and IO muscle thickness changes during all tasks were normalized according to the supine rest position. Results: Transverse abdominis muscle thickness changes were increased in the quadruped and sitting positions compared with other positions ( Conclusion: Our study revealed that participants with chronic low back pain exhibited increased TrA muscle activity in the sitting position on a gym ball and in the quadruped position compared with during leg tasks. However, the EO muscle thickness changes were increased during an ADIM with a sphygmomanometer under the abdomen.