The traps need focused retraction and depression work to prevent imbalances. For this exercise, start in the regular seated row position while making sure the back is arched and the chest pushed up.
From here, squeeze the shoulder blades together and hold for several seconds. By focusing on pushing the chest up and out, the shoulder blades are more easily depressed.
Foam rollers, lacrosse balls, back walking, kettlebells. Can these work as tools to fix tightness and pain? Not when you use them like this. Here's what works better.