The effects of precise contraction of the pelvic floor muscle using visual feedback on the stabilization of the lumbar region.

[Purpose] The purpose of this study is to verify whether precise contraction of the pelvic floor muscle (PFM) using visual feedback actually affects the thickness of abdominal muscles. [Subjects] The subjects were 29 healthy adults in their 20s who consented to participate in this study. [Methods] This study provided visual feedback on PFM using one ultrasound device and identified changes in the transversus abdominis (TRA) using another ultrasound device. Abdominal muscle thicknesses were measured by ultrasound under three conditions (rest, PFM contraction, PFM contraction with visual feedback). [Results] There were no statistically significant differences in the external oblique (EO) and internal oblique (IO) muscles between the measurements taken at rest and during the contraction of the PFM, and between those taken at rest and during the contraction of the PFM with visual feedback. There were significant differences in the TRA. In particular, TRA thickness was highest in the order of PFM contraction, PFM contraction with visual feedback, and rest. [Conclusion] Hollowing with visual feedback is not an efficient stabilization exercise method for the PFM.