ABSTRACT
PURPOSE: The purpose of this study was to examine the effects of plank exercises with resistance of one-sided hip adduction on abdominal muscle thickness. METHODS: Thirty subjects were divided into a group that underwent plank exercises with one-sided hip adduction resistance (n=15) and a group that underwent plank exercises only (n=15). Their changes in abdominal muscle thickness before the experiment (n=15) and three and six weeks after the experiment were analyzed using a two-way repeated analysis of variance at a statistical significance level of α=0.05. When there was any interaction between the time of measurement and each group, post hoc t-tests were conducted at a statistical significance level of α=0.01. RESULTS: The results of the experiment showed statistically significant differences in the thickness of the rectus abdominis, internal oblique muscle, and transversus abdominis, depending on the time of measurement and the interaction between the time of measurement and each group (p<0.05). Statistically significant differences were observed in the thickness of the external oblique, depending on the time of measurement, the interaction between the time of measurement and each group, and variances between the groups (p<0.05). CONCLUSION: The results of this study indicated that plank exercises with resistance of one-sided adduction are effective for increasing abdominal muscle thickness. The study's overall findings will likely be used as basic data for lumbar stabilization exercises and rehabilitation treatment.