aggravated back at work

I significantly aggravated my lower back today standing up at my desk and putting my Design Manual (~10 lbs.?) back onto a shelf. A minor activity, yes, but apparently enough to set my back off. Pain level shot up from a 2-3 to a 5-7. I took a vicodin and a flexiril and basically vegetated at my desk until I was coherent enough to drive home. Lovely. I spoke to some of our admin folks and have decided to file a Workers Compensation claim.