Pressure biofeedback is a tool designed to facilitate muscle re-education by detecting movement of the lumbar spine associated with a deep abdominal contraction in relation to an air-filled reservoir. Pressure biofeedback readings of an abdominal ‘drawing-in' manoeuvre, designed to recruit the deep abdominal muscles, were taken from 45 patients. They were classified into three groups: lumbar symptomatic, non-symptomatic, and those who had previously had lumbar symptoms that had now resolved. Subjects were taught an abdominal drawing-in manoeuvre and the mean of three readings using the prone test was calculated. Comparison between groups using an unrelated ANOVA demonstrated a statistically significant difference between the lumbar symptomatic and non-symptomatic groups at the p < 0.05 level. The findings of this study provide evidence to support previous research, which indicates that a difference exists in the deep abdominal function of patients with and without low back pain. Additionally it is suggested that the pressure biofeedback unit may be considered as a useful tool to act as an indicator of deep abdominal function.