Evaluation of Trunk Oblique Muscle Activities in Baseball Batters Using T2-Weighted Magnetic Resonance Imaging

Yanaka, T, Imawaka, T, Kojima, C, Otomo, M, Ohnishi, T, and Hoshikawa, M. Evaluation of trunk oblique muscle activities in baseball batters using T2-weighted magnetic resonance imaging. J Strength Cond Res 39(1): 48-53, 2025-This study investigated abdominal oblique muscle activity using T2-weighted imaging in baseball batting. For this purpose, 17 baseball batters (21.6 ± 2.7 years, 173.9 ± 4.0 cm, 77.5 ± 7.6 kg) performed 100 toss-batting trials. Before and after toss-batting, 3 Tesla magnetic resonance imaging scans were performed to obtain the T2 values of the 4 abdominal external and internal oblique muscle pairs. The results showed that the T2 values of all abdominal oblique muscles were significantly increased after the 100 trials ( p < 0.05), with no differences in these increases between the muscles. The rate of change in the T2 values was 1.0 ± 3.9% and 4.2 ± 5.2% for the external and internal oblique muscles on the pitcher's side and 3.2 ± 5.1% and 0.9 ± 2.5% for the external and internal oblique muscles on the catcher's side, respectively. These findings indicate that the activity levels of all abdominal oblique muscles during baseball battings are similar and lower than those of the agonist muscles used during resistance exercise and sprinting. These findings suggest that baseball batting is a low-intensity exercise of the abdominal oblique muscles, but adequate training of each abdominal oblique muscle may improve batting performance and prevent injury.