Not feelin' it today.
At least I have (belatedly) discovered the cause of my increasing lower back woes. When I bought the new computer last year, I also bought a righteous modern widescreen 25" monitor to go with it. Said monitor, however, is not height-adjustable and, even with my desk chair lowered as far as it will go, my eyes are level with the top edge of the monitor itself. Any extended surfing of the intertubes, which comprises a large chunk of my days, finds me leaning forward, elbows on knees or the edge of the desk to support myself.
As a result, the muscles of my lower back have become unemployed, and grown soft and lazy and tend to rebel when asked to do work, like bending over to empty or load the dishwasher, manage the extension cord for the lawnmower, or even, as happened yesterday, get a range bag out of the trunk of the Bimmer. This is clearly unsat. I have always been proud of having good posture, and it's going to go away if I don't do something about it, starting with a cheap monitor stand to jack it up 4" or so.