A couple weeks ago, my wipers were frozen to the windshield. Not thinking, I bumped them a couple times with the lever to wipe off some snow/slush/ice stuff. Obviously, they didn't move. Now that they've thawed, they don't go as far as they used do. Before I did this, the driver's one would go clear to the top corner of the windshield, clearing off the whole thing. It stops about 4-6 inches short of the windshield now, essentially not going past straight vertical. Is there a spring or something that I've tweaked or what?

 

Check the wiper transmission isn't tweeked out of shape.