Effects of real-time ultrasound as biofeedback on transversus abdominis activation level in patients with chronic low back pain

Objective To investigate the effects of abdominal drawing-in maneuver with real-time ultrasound biofeedback on transversus abdominis activation level during functional tasks in different positions in patients of chronic low back pain with stabilization-deficit. Methods Nineteen patients of chronic low back pain with stabilization-deficit were randomly divided into verbal instruction group(n=9) and ultrasound biofeedback group(n=10), and received abdominal drawing-in maneuver with verbal instruction and ultrasound biofeedback respectively. Percentage changes of transversus abdominis thickness during supine and upright loaded tasks were compared before and after intervention. Results After intervention, percentage changes of transversus abdominis thickness increased significantly in verbal instruction group during supinehip external rotation, straight leg raising and upright loaded functional tasks (P 0.05). Conclusions Ultrasound image could effectively assess the thickness changes of transversus abdominis in patients with chronic low back pain during supine and upright loaded functional tasks. Ultrasound image could provide chronic low back pain patients with real-time and dynamic visual feedback. However, compared with verbal instruction, adding real-time ultrasound biofeedback to abdominal drawing-in maneuver does not further increase the transversus abdominis activation level. Key words: Ultrasonography; Transversus abdominis activation; Chronic low back pain