unknown origin

I have no recollection of doing so but my elbow started displaying all the signs of having been quite severely twatted about the distal end of the humerus, to the extent of swelling up markedly by the time I got home, where I immeditely rootled about in the kitchen for some ibruprofen and in my sock drawers for a tubigrip. I first noticed it sitting at my desk sometime in the mid-morning so suspect one of the awkward doors between the changing room and the rest of the office as I'm sure I'd have remembered a wing mirror clipping it on the way in. It was sort of slightly better when wandering around at lunchtime but worsened again when sitting still. It got me home safely, with the bobbling by the bumps in the road of the swollen bit making me consider stopping and employing a spare sock with the end cut off as a means of stabilising it. It was threatening to stop me getting to sleep until I removed the tubigrip and tried paracetamol and resting it above my head.