Yeah, it’s a really common problem! Your right, your right arm might be stronger. I guess most of us tend to use our dominate arm much more, so it could be stronger and maybe even more coordinated than your non dominate side! Test it out, do some alternate dumbbell bicep curls. If you can do the same amount of reps with both arms with equally good form, then I personally wouldn’t don’t stress about it too much. Your right arm may always be bigger. You just don’t want there to be a significant strength imbalance between your arms, that could cause you issues later on. If your right arm is stronger than your left, I would try sticking to one-arm dumbbell exercises until your left arm is as strong as your right. Keep the reps exactly the same for both arms though, don’t be tempted to do more reps with your right arm just because it's not tired. With your back (obviously your biceps play a large role in back exercises), you can do one-arm dumbbell rows. What else? I’m struggling to think off the top of my head of any other unilateral back exercises. Still half asleep.. Anyone else have any ideas? Oh well, do them first in your back work out anyway. Can you let us know how you go?