Validating a clinical measure of levator hiatus size

Objective: We evaluate the interrater reliability of levator hiatus (LH) size and correlate size to other measures of muscle function. Study design: Participants were examined independently by 2 examiners. During maximal contraction of the levator ani, the muscle was assessed by using Brink's scale. The LH was measured in the transverse and sagittal dimensions by digital palpation. The paired t test was used to compare continuous variables and Spearman's coefficient was used for correlations. Results: The mean LH transverse was 4.5 cm and the mean LH sagittal was 3 cm. The inter-rater correlation for the LH transverse measurement was 0.6 (P < .01) and 0.8 (P < .01) for the LH sagittal measurement. The correlations between the LH size and Brink's scale were moderate (correlation coefficient -0.4 to -0.5, P < .01). Eighty-three percent of measurements were within 1 cm. Conclusion: This technique for clinical measurement of levator hiatus size shows good interrater reliability.