On our last building project, I messed up my knees pretty bad. I crawled around on the floor for at least a week laying and grouting slate tile, and my knees still snap, crackle and pop when I walk up stairs. That was more than three years ago.

Today I think I dealt my patellar cartilage its death blow with one of these here gizmos:

One uses such a device to stretch and anchor carpet into place. One does this by smashing on the padded end with one's knees, repeatedly, whilst the teeth on the business end dig into the carpet.

As I've said before, whatever minimal mechanical aptitude I once had has gone the way of my math skill. I surely wasn't using proper technique, but I managed to smash the crap out of my kneecaps for the few hours and all I had to show for my agony was 14 treads now covered in el Cheapo $0.83/foot Home Depot carpeting.

Hopefully I'll be able to walk tomorrow. Not counting on it, though.