Cold and windy. High 40s. Keith, Ben and Richie. Back muscle issue got much worse today. After playing front nine in discomfort and popping three Advil on 7th hole, by the time we started second nine, I was in trouble. We decided to replay front nine, 'cause course got slow. Painful drive on beginning of second nine. Then on 2nd, with 24H, into wind, got stabbing pain in right side back at finish of swing which nearly buckled me over. I was done. Rode around in the cart for the remainder of the round. Tried some chipping, but even that was irritating back. Need to put the clubs away--totally, not practice swing at all--for the next week and hope for the best. Have a feeling it may need more than a week to heal. Seems pretty bad. Lots of ice afterwards. Disappointed, but now virtually sure this has had a lot to do with my loss of distance and accuracy off the tee all month. It finally came to a head. Had to cancel round scheduled for tomorrow.