I have what feels like 2or3 golf ball size lumps on each side of my lower back. I can move them around by pressing on the area. feels like they are under the skin on top of mt lower back muscle. when my lower back is sore i cant massage the muscle because the lumps are in the way. when i do have that area massaged it has to be rubbed real hard. it will feel better but will leave bruises on my back from being rubbed so hard. they dont cause pain just soreness. feels like i need to stretch out my lower back. but the stretching doesnt help tje soreness. Feels like they are right on top of my lower back muscles. what is this.