Strained my back this morning so standing and walking hurts. Especially when I was climbing the stairs out of my apt. bldg. w/ my bike and backpack. Ride to work was fine except for the truck that did an unsignaled half U-turn to back up into a driveway. He swung left, then swung right as I was passing. I aimed for the shrinking gap and rode through. I don't think he cared that he almost took out a couple of cars while doing this maneuver let alone even seen me.