I want to develop muscle on my obliques, I was doing Dumbbell and Barbell side bends, but after a few weeks I started having lower back pain, what else would you advice to train on? thank you.
Doing a lot of oblique work is actually a TERRIBLE idea. It'll make your waist bigger.
What happens when you exercise a muscle? It grows.
Do you want a bigger and blockier waist?
I wouldn't do any oblique work at all man. Your obliques get more then enough stimulation when doing big compound movements like squats, overhead press etc.