Update: after months of wife walking on back, got a new 'pop'. There has always been a spot between my shoulder blades that felt like it should pop or crack when she was standing there, but never did. She implored a new technique this week. She leans forward on balls of feet right alongside both sides of spine, then shifts weight back and forth like kneading bread, @ 1 second per each foot. This(for me) helps to relax my muscles and flex my spine. So she was doing this, the 'pop' on right side real deep then 'pop' left side very deep as well. Very satisfying. I thought at the time it was that spot that always felt like it should pop. Still felt a little tight though. Well, guess what? It was, next day shoulder feels good. next day even better. Long story short that knot on my left shoulder that has been there for 2 years, has been gone fore almost 2 weeks now.
Still feels like one more up needs to crack for me. I have had this experience before. When we first started after a couple weeks got a big crack that was so satisfying. I do know this is standard protocal for chiros. they say can take months of adjustments to get a hard spot.
Oh, also another technique. I roll up a hand towel and put it under spine where i need to pop. Then she stands on my chest. Got a real good pop a couple times that way. I gotta be real relaxed though. If I tense up, dont work. took some getting used to, I was a little cautious at first cause I didn't want to get injured. Im confident now she is not to heavy for me, so now I take a big deap breath and as Im exhaling she steps on. This (for me) produces a good crack once a week or so.
Just wanted to let you all know, my back feels really good! Really Good! What a relief. Hope this helps.
Oh, I do foam roll regularly too, or tennis ball.