proper form for lower back extension

[FifaFifa15]

can anyone help me out with the proper form for lower back extension? ive never really been sure when my range of motion should start and stop

i know this might be hard to explain, but is there anything I could expect to feel that tells me ive gone too far?

 

[newf]

There's a few methods just do what feels the best or ask someone in the know if your at a gym

http://www.exrx.net/Lists/ExList/WaistWt.html#anchor1945210