the first few times i ever did pump i used 1kg on each side. i dont have a back injury but i think that if it is something you want to do it should be ok. keep to the minimum weight until you suss it out and of course try to get the technique right. (thats my opinion and i have no training or experience with injury or PT though) CONGRATS on your weight loss!!!

i went to the gym this arvo to do pump and they had changed the timetable.. there was something called boxfit on. i freaked out a bit.. but went through with it and it was really good actually. i dont think i am going to be able to move my arms tomorrow though!