Along the same vein as our last post, consider abducting the leg 30 degrees, which increases gluteus maximus activity, lessens anterior pelvic tilt and lessens erector spinae activity. Of course, pelvic tilt should have clued you in to a weak core in the 1st place : )
PURPOSE: To investigate how the erector spinae (ES) and gluteus maximus (GM) muscle activity and the anterior pelvic tilt angle change with different hip abduction angles during a bridging exercise.
METHODS: Twenty healthy participants (10 males and 10 females, aged 21.6 ± 1.6) voluntarily participated in this study. Surface electromyography (EMG) signals were recorded from the ES and GM during bridging at three hip abduction angles: 0°, 15°, and 30°. Simultaneously, the anterior pelvic tilt angle was measured using Image J software.
RESULTS: The EMG amplitude of the GM muscle and the GM/ES EMG ratio were greatest at 30° hip abduction, followed by 15° and then 0° hip abduction during the bridging exercise. In contrast, the ES EMG amplitude at 30° hip abduction was significantly lesser than that at 0° and 15° abduction. Additionally, the anterior pelvic tilt angle was significantly lower at 30° hip abduction than at 0° or 15°.
CONCLUSIONS: Bridging with 30° hip abduction can be recommended as an effective method to selectively facilitate GM muscle activity, minimize compensatory ES muscle activity, and decrease the anterior pelvic tilt angle.
Kang SY1, Choung SD2, Jeon HS3. Modifying the hip abduction angle during bridging exercise can facilitate gluteus maximus activity. Man Ther. 2016 Apr;22:211-5. doi: 10.1016/j.math.2015.12.010. Epub 2016 Jan 2.