The lesson has been handed down from parents for years: Do as I say, not what I do. I'll pass along another example here.
The tread on my old running shoes -- the ones I wear for casual use at this point, and not for running -- has been about gone in spots for a little while. I've been meaning to go to the shoe store to pick up replacements, as I had slipped a couple of times. Naturally, I didn't get around to it.
So on Monday afternoon, I rounded the corner of my house, headed down the stairs, out the door, into the car and off to work. Fate had other plans. My feet came out from under me on the stairs, and I went crashing to the ground, bouncing down a stair in the process.
The results of this spill: a scraped left arm, a small scrape on my right hand, and a very sore tailbone. It took about 18 hours for me to walk anything close to normally, as I looked like I needed a cane at work. It still hurts to get up and down from a chair or from the car. You'd be surprised how many movements you make in a day that are taken for granted.
I checked the various Web sites at work on such injuries, and the messages were similar. Unless there is bleeding, there is no emergency (and there wasn't here). It's just a case of having a sore tailbone for a while.
Therefore, take a look at your sneakers every so often, and don't try to squeeze a couple of more weeks out of them when they are dead. The butt you save may be your own.