Inter-rater reliability of pressure biofeedback unit among individuals with and without chronic low back pain

Objectives: To determine the inter-rater reliability of pressure biofeedback unit among individuals with and without chronic low back pain. Methods: This cross-sectional survey was conducted from February 2021 to March 2021 at the Physiotherapy Department of the Sindh Institute of Physical Medicine and Rehabilitation. Sixteen subjects which were recruited with and without chronic low back pain.(CLBP). During the test, abdominal drawing in movement was monitored by measuring a change in pressure detected in PBU. Each test was performed once by two trained assessors with period of seven days. Reliability indices of Pressure Biofeedback (PBU) measures including the Intraclass correlation coefficient [ICC] and Band Altman plot were analyzed. Results: This study found an intra-class correlation coefficient (ICC) = 0.94 [95% confidence interval (CI) (0.37, 0.99] for inter-rater reliability in healthy individuals, and an ICC of 0.97 (95% CI 0.97, 0.98) for inter-rater reliability in CLBP. The interrater agreement (Limits of Agreement-LOA=5.92, -3.9 mmHg) in CLBP and the interrater agreement (LOA=5.75, -3.25 mmHg) in healthy individuals were within the limits of agreement on 95% of occasions. Conclusion: Pressure Biofeedback Unit has showed excellent inter-rater reliability in measuring Transverse Abdominis muscle activity for individuals with and without chronic LBP.