The Use of Rehabilitative Ultrasound Imaging for Feedback from the Abdominal Muscles during Abdominal Hollowing in Different Positions

Abstract

[Purpose] This study was conducted to investigate the effects of rehabilitative ultrasound imaging (RUSI) feedback during the abdominal hollowing exercise (AHE) in three different positions by monitoring the changes in the thicknesses of the abdominal muscles. [Subjects] The subjects of this study were 42 healthy male adults who listened to an explanation of the study method and purpose and agreed to participate in the experiments. They were divided into an experimental group of 21 subjects who received RUSI feedback and a control group of 21 subjects who did not receive RUSI feedback. [Methods] The thickness of the abdominal muscles was measured during rest and AHE in three positions. The thickness changes between rest and AHE were compared between the two groups. [Results] The difference in internal abdominal oblique (IO) thickness changes between the groups were significant. The differences in external abdominal oblique (EO) thickness changes were only significant among the positions. A post hoc analysis of the differences in EO thickness changes among the positions found significant differences between the crook lying and four-point kneeling positions. The transversus abdominis (TrA) thickness changes showed significant interaction between group and position. [Conclusion] RUSI feedback assists the independent activities of TrA by decreasing the thickness changes of global muscles such as IO and EO. Furthermore, crook lying is a more effective position in AH training with RUSI feedback than the other two positions as it increases TrA thickness changes while minimizing those of EO.