Reliability of pressure biofeedback instrument in patients with low back pain

BACKGROUND: Treatment programs for low back pain are of great varieties, but there is still no a definite treatment. Pressure biofeedback instrument is a tool to measure abdominal muscle activity, and its reliability in the treatment of low back pain is less reported. OBJECTIVE: To explore the reliability and feasibility of the pressure biofeedback instrument for assessment of low back pain. METHODS: Thirty patients with chronic low back pain were enrolled and subject to four kinds of postures: posture A was prone position; posture B was supine position with flexion of the knee joints, posture C was supine position with unilateral flexion of the hip and knee joint, posture D was prone position with unilateral shoulder flexion. Intra-abdominal pressure values under the different postures were measured twice within a week in the same subject. Intraclass correlation coefficient (ICC) was used to assess the reliability. RESULTS AND CONCLUSION: Posture A had good test-retest reliability, and the value of ICC was 0.853 (95% confidence interval: 0.691-0.930); posture B showed moderate test-retest reliability, and the ICC value was 0.751 (95% confidence interval: 0.477-0.882); posture C also had moderate test-retest reliability, and the ICC value was 0.789 (95% confidence interval: 0.557-0.900), posture D had good test-retest reliability, and the value of ICC was 0.892 (95% confidence interval: 0.641-0.919). Therefore, the pressure biofeedback for evaluation of low back pain has good reliability, which can be used for the evaluation of low back pain.