In front squats your back always give out first?? 
Only if you can't move properly, don't know how to work on your range, and if your "upper back" gives out then you're a dork who has gone too high in reps and not realised that an isometric rhomboid contraction is always going to be weaker than the myriad of muscles you are trying to stimulate when doing a front squat.
this explains so fucking much!!!!!!!!!
i used to do real heavy front squats
i mean singles with 155kg at 82kg natural bw and stufff
and never had an injury
recently i started doing light front squats with 100kg for reps and reps (and i'm roided up 95kg now)
and hurt my back all the time
now this can be why