sPL/PE1>im glutes on the ground?

sPL/PE1>im is an exercise where I initially had poor mobility, but that has improved a lot. I can now do it the way it is done in the video (I'll double check this later today by filming myself).

 

But I wonder about the second focus point in the exercise description. It says "Keep the glutes on the ground at all times", but in the video the athlete clearly rotates his hips, lifting one of the glutes off the floor on each side of the rotation. Is that acceptable form? (I am hoping it is, since then I would be done with this one. )

One side can get a little light on the floor, it's not a huge amount of lift.

Ok, thanks for the clarification. I'll do the same as in the video then.

What did you do to improve your mobility there?

I just did the mobility exercise. It improved over time. For the PE itself (scapular shruggs) I could probably have started at week 9, but because of the mobility, I decided to back down to week 5 to give myself more time, and went from there. I still need to film myself to confirm I have the mastery as I think, but I definitely have improved and should be pretty close in any case. The first time I did it I could barely move my legs in that position/direction.