HS/PE7 what can touch the wall?

On HS/PE7 (face to wall HS), what is acceptable to touch the wall other than the feet?

 

I understand the "staying tight and extended", and that generally this means nothing but the feet will touch the wall, like in the video demo.  However, as one gets their hands closer and closer to the wall, it would seem that eventually something else may touch the wall (ribcage or large quadriceps, for example).

 

What is acceptable, assuming one is staying tight and extended?  I've been doing my best to not have anything other than my feet touching the wall, keeping an extended body.

 

Thanks.

feet, upper ribs, and quadriceps touch the wall, avoid hips and stomach from touching.

 

I think if you look at the later PE9 or 11 this should be a cue written in the focus points.