There are many people showing images and videos in which posterior pelvic tilt is suggested to maximize the glutes activation in some exercises. One of this is hip thrust.
Since glutes may posteriorly tilt the pelvis, I understand that working in ppt may increase their ROM. But... why is it safe with an external load (for instance a barbell in hip thrust)?
I'd say that the barbell generates some shearing and compressive forces on the low back. Why can we keep it flexed?