This is my favorite movement to strengthen the back in a pulling/rowing motion. It's a staple of the Chinese Olympic lifters.

Chest-Supported Row

This exercise will take the lower back out of the movement, and you can't really cheat. By focusing only on your back you'll develop more contractile strength and a superior mind-muscle connection.

Coaching Notes

1. Always hold a slight squeeze at the top.
2. Don't rely on momentum to get the weight from point A to point B. Focus on a quality contraction of the back muscles.
3. You can do the movement with kettlebells, dumbbells or a barbell. They all work and you should rotate through all of them. Become strong in all types of rowing motions. The pulling angle with a bar will be different than the one with a dumbbell, especially if you use a neutral grip.
4. Perform sets of 6 to 8 reps for a few weeks, then add weight and drop down to 4 to 6 reps, but only when you've built a solid mind-muscle connection with the back.