Crushed my L5 vertebra in 1983. Spent 3 months in a brace. Months of physical therapy, ultrasound, massage. You want to talk about chronic pain.
I would stretch and exercise and the chronic pain would persist, for decades. In 2007, a GF brought me to her yoga class. What a transformation. If only the other folk in that class weren't such snowflakes.
It's been 13 years now and I have not had the daily pain or stiffness, as long as I keep up the practice. And I still do things like haul refrigerators upstairs, put 40# of lead weight in a plate carrier and do duck-walks up steep slopes or swing a sledgehammer for a workout.