Comparison of Muscle Activity and Muscle Thickness According to Knee Flexion Angle during Supine Bridge Exercises using the Abdominal Drawing-in Maneuver on an Unstable Surface

This study evaluated changes in deep trunk muscle thickness and lower extremity activities during bridge exercises with the abdominal drawing-in maneuver. Bridge were conducted on an unstable surface at different knee flexion angles (60º, 90º 120º), aim of identifying more effective for exercises. included 21 healthy adults, aged 20–27 years. Biceps femoris (BF), rectus abdominis, activity was measured using electromyography. The thicknesses transverse abdominis (TrA), external oblique (EO) internal (IO) muscles measured. BF (p = 0.000, partial η2 0.670) increased considerably as angle decreased. TrA 0.883) IO 0.892) significantly increased, while EO 0.893) decreased When performing maneuver surface, should be 120º 60º to increase stability activity, respectively.