Lower Back Rounding

[Charlie]

I realised I have a bit of a problem with my lower back rounding when I reach below parallel on the front squat, so I went back to Mehdi's article.

The ways to fix back rounding as stated by Mehdi are: hamstring stretches, squat stretches, supermans, and box squats. First question is: what hamstring stretch should I be doing? Next: what are squat stretches?

And are supermans bad for your lower back? I didn't think it was good to bend your lower back in the manner? I thought it would give you lordosis or something.

[Mehdi]

Squat stretch, sit in that for 30 sec, keeping chest up

 
Actively increasing the range of motion of your spine (flexion/extension/rotation) is bad. Supermans: squeeze glutes hard while hyperextending your back.