Yes, definitely. A good TENS unit, when on EMS mode (pulsation), relieves deep adhesions and knots. It prevents tendonitis in my biceps due to the surgery I had. I had surgery for a SLAP tear, and biceps tenodesis. I also have a slight tear in my opposite shoulder. I use electrotherapy as general maintenance, and am practically pain free. It's also been great on my back, to relieve spasm / knots. I use it almost religiously on my scapular area.
If you ever get one, feel free to ask questions in here about it, but try to get some general guidance from a sports therapist on it's use. You have to connect the electrodes to the proper muscle bellies / areas, and learn your way around somewhat.