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

Table 2. Ratio of relative muscle thickness at activation and rest during bridging exercises.

Joint angle	60º	90º	120º	F	p	partial η²
Muscle	Mean ± SD	Mean ± SD	Mean ± SD	F	p	partial η²
External oblique	0.91 ± 0.20 ^a	0.85 ± 0.23 ^b	0.84 ± 0.22 ^c	18.091	0.000^*	0.893
Internal oblique	1.27 ± 0.30 ^a	1.42 ± 0.19 ^b	1.54 ± 0.34 ^c	61.001	0.000^*	0.892
Transverse abdominis	1.31 ± 0.27 ^a	1.50 ± 0.32 ^b	1.65 ± 0.39 ^c	84.652	0.000^*	0.883

^a Significantly (p < 0.05) different when compared to 90º and 120º.^b Significantly (p < 0.05) different when compared to 60ºand 120º.^c Significantly (p < 0.05) different when compared to 60º and 90º.