Abstract
[Purpose] The purpose of the present study was to investigate changes in activation ratios of the transversus abdominis (TrA), internal abdominal oblique (IO), and external abdominal oblique (EO) at knee angles of 60, 90, and 120 degrees when an abdominal drawing-in maneuver (ADIM) was introduced to a bridge exercise. [Subjects] A total of 44 healthy people agreed to participate in the study, and based on age, height, and weight, these subjects were matched and randomly assigned to either the bridge exercise group (n=22) or the bridge exercise with ADIM group (n=22). [Methods] The thickness of the abdominal muscles was measured using a SonoAce X4 (Samsung Medison Co., Ltd., Seoul, South Korea). The main outcome variables were the ratios of the TrA, IO, and EO thickness during the exercise versus in the relaxed position (TrA, IO, and EO activation ratios). [Results] Differences were found in the TrA and IO activation ratios at knee angles of 90 and 120 degrees between the groups. The TrA and IO activation ratios increased at angles of 90 and 120 degrees compared with 60 degrees, within the bridge exercise with ADIM group. [Conclusion] In conclusion, a knee angle of 90 degrees might be a more effective angle during the hooklying bridge exercise with an ADIM when spinal stabilization exercises are performed or when studies are prepared in this area.
