RESUMEN
PURPOSE: This study was conducted to investigate the effects of blood flow restriction and different support surfaces for bridge exercises on the thickness of the transverse abdominis and multifidus, which are trunk-stabilizing muscles. METHODS: The study's subjects were 45 adults who were divided into three groups that performed bridge exercises over a six-week period on their respective support surfaces after blood flow restriction. Changes in the thickness of the subjects' transverse abdominis and multifidus muscles were measured using ultrasonography before the experiment, then three and six weeks after the experiment. The changes in each variable over time were analyzed using a repeated-measures analysis of variance (ANOVA). RESULTS: The transverse abdominis showed significant differences in muscle thickness with regard to time and the interaction between time and each group (p0.05). The multifidus showed significant differences in muscle thickness with regard to time, the interaction between time and each group, and changes between groups (p<0.05). CONCLUSION: Blood flow restriction and different support surfaces for bridge exercises led to significant differences in the thickness of the transverse abdominis and multifidus. This study's results may be used as the basis for future studies and for rehabilitation in clinical practice.