Background and Purpose: Activation of transversus abdominis (TA) is regarded by many as an integral part of back pain management. A measuring tool to detect activity of TA, The Pressure Biofeedback Unit (PBU), has been devised. This study aimed to determine the intra, inter and test re-test reliability of the PBU.

Method: 3 raters (GM, TR, JL) and 10 subjects (mean age 23.2 yrs, ± 4.5) were recruited fulfilling specific inclusion criteria. Ethical approval was gained from the Institutions Ethical Committee. Following a period of training in the abdominal drawing-in test each subject was assessed in a randomised order during one visit by all three raters. All raters and subjects were blind to the result of previous attempts. All subjects were assessed on a second visit a week later by one rater (GM). ICC’s were calculated to determine intra, inter and test re test reliability.

Results: Intra reliability for the three raters (GM,TR, JL) at the first visit were.589.784.869 respectively. Inter tester reliability was.788, with test re -test reliability.766. Of note intra reliability for rater GM for the second visit was.986.

Conclusion: The Pressure Biofeedback Unit is a reliable tool when utilised with a population of subjects that can perform the abdominal drawing-in test. Further research should establish its reliability with a back pain population. Improvements in consistency on the second visit could indicate that minimal practise of the task enhances this motor skill.