Played hockey. increased lower back pain during game. following day cannot bend over. suggestions other than rest and stretching?

Get soft tissue exam: Have physician check for enthesiopathies that is where origin of long support back muscle quadratus lumborum is anchored to sacrum on both sides. Needling of painful areas may help. There also may exist trigger points.

First, try to see : If you are have good flexibility to begin with then consider more core strengthening. Try heat via heating pad or hot tub. If no response, you can try taking some otc medication if no contraindications when you play. If no help, then seek evaluation by a physician. If overweight, try to trim down and if smoking, stop. If you are not a flexible person then you need to work on this as well.