By development, I assume you mean size? Your back muscles are very resilient, and there are a couple possibilities:
- You aren't working them heavy enough
- You aren't working them with enough volume
Barbell rows and dumbbell rows are excellent options, but don't forget dead lifts. The shrugs and pullups, while awesome exercises, do the least for the muscles you are wanting to hit. If you are doing barbell rows and/or dumbbell rows, the seated rows don't add anything. Instead, focus on volume.
You'll want to go as heavy as you can. If you are more concerned with size than using a lift in competition (like deadlifts), then I recommend getting some weightlifting straps. They will let you lift heavier without your grip limiting your back work. To get some size it needs to be worked hard with a lot of volume.
- You should be able to row at least as much as you bench
- You should be able to deadlift more than just about any other lift (save shrugs).
A good high volume program to run that will definitely build size is Smolov Jr. It's a volume based approach designed to improve your strength on just about any major exercise. You start by knowing your 1RM (absolute heaviest weight you can lift one time) for that exercise. Then you do your first week like this:
- 70% 6x6 (6 sets x 6 reps)
- 75% 7x5 (7 sets x 5 reps)
- 80% 8x4
- 85% 10x3
- 70% + 10-20lbs, 6x6
- 75% + 10-20lbs, 7x5
- 80% + 10-20lbs, 8x4
- 85% + 10-20lbs, 10x3
- 70% + 15-25lbs, 6x6
- 75% + 15-25lbs, 7x5
- 80% + 15-25lbs, 8x4
- 85% + 15-25lbs, 10x3
In short, week 3 is 5 lbs heavier than week 2. Week 2 is 10-20lbs heavier than week 1. On Week four you rest and then test your new max on Friday.
I've been running this for bench and rows, and while I'm not aiming for size it is increasing. The back can handle being hammered, and in some cases it needs it.