RC/PE2 Ground Rows

Hey guys, can anyone check my ground rows? Doing them I didn't notice but after watching it seems that I'm arching a bit too much.

This exercise is really giving me a hard time, it's tough to progress! I can easily do 15 or more reps on my first set but my stamina isn't good enough to even do 4x12 yet. I found I didn't progress by doing 5x9 for several weeks so I'm increasing rep by rep. This day I did 6x10. This set was filmed after the 6x10.

Thanks in advance for the advices!

 

Hey Tom, definitely too much arc. the hips extension should be reached not by lumbar muscle but posterior pelvic tilt plus glutes activation. this is the only one alternative.

Thank you @Alessandro Mainente, I will try this today and film it again. 

I tried applying what you said @Alessandro Mainente, sorry for the bad framing and darkness. 

Here I did 5x9, and filmed all my sets.

I think I need to correct a bit more, but I'd say I'm much less arched than last time. What would you say?

 

I say "i like them" ;-) ;-)