Been dealing with this for a while, in my 40's and on the east coast, so most days are smaller than chest high. I'm regular footed and tend to surf mostly rights on smaller high performance fish type boards. Not sure if its the pumping/groveling in small waves but I have this persistent pain in my left lower back that comes on after a few waves. Its not debilitating, but is beyond annoying. It usually goes away after a day or so. I don't have the issue on the bigger days where I'm not working as hard to get speed. I've had on and off lower back pain my entire adult life and greatly attribute to stress but I think this is different. Is this the case for anyone else? Any insight on stretches/exercises would be greatly appreciated. I've just dealt with it for years but want to try to do something about it. Thanks again.