Abstract
BACKGROUND: The abdominal drawing-in maneuver (ADIM) is widely used in sports physical therapy and rehabilitation to selectively activate deep trunk muscles. Although the ADIM is effective for motor control retraining, previous studies suggest that it may be unsuitable as a breathing strategy during high-load tasks because it limits intra-abdominal pressure (IAP) generation. Trunk rotation in the horizontal plane is a fundamental component of many functional and sport-related movements and requires coordinated trunk stability and force production; however, the effects of the ADIM on IAP and torque during trunk rotation remain unclear. PURPOSE: The purpose of the present study was to clarify the effects of the ADIM on IAP and trunk rotational torque during trunk rotation. STUDY DESIGN: Crossover, randomized controlled study. METHODS: Fifteen healthy young adult males performed seated isometric trunk rotation tasks under two conditions: spontaneous rotation (SR) and trunk rotation with the ADIM (DIR). IAP was measured using a catheter-type pressure sensor. Trunk rotational torque was measured with a custom-manufactured trunk rotation dynamometer. Inspiratory volume was normalized as %inspiratory volume. Outcomes were compared between conditions. RESULTS: IAP was significantly greater in SR (96.7 ± 31.4 mmHg) than in DIR (34.9 ± 15.9 mmHg) (p < 0.01, d = 2.48). Torque was also significantly greater in SR (68.7 ± 20.2 Nm) than in DIR (49.1 ± 17.7 Nm) (p < 0.01, d = 1.03). %inspiratory volume was significantly greater in SR (66.9 ± 16.2%) compared with DIR (26.4 ± 17.4%) (p < 0.01, d = 2.41). Large effect sizes were observed for all outcomes. CONCLUSION: Performing trunk rotation with the ADIM attenuated increases in IAP and trunk rotational torque. These findings indicate that ADIM influences both pressure generation and mechanical output during trunk rotation. LEVEL OF EVIDENCE: 2.