Cleaning and pain go figure

So tonight is my cleaning night. I like to do things like vacuuming and straightening and laundry on Thursday nights so I have my weekends free. I'm probably one of those crazy people who happens to love to vacuum. When I'm stressed there is nothing like taking on the apartment with my Oreck. There I was manned with a clean vacuum cleaner bag and I was ready to have a good time. Now keep in mind that my apartment isn't all that large so it really doesn't take all that long to do plus I happen to love it when you have those neat vacuum lines in the carpet. Yeah I know it's a sickness but what can I say? I start, I get the livingroom and the dining area done so far so good. I move in to do the bathroom floor and the throw rugs. I'm in pain, where is that pain coming from? I stop and I sit a minute. The pain is in my right butt cheek, yes world I said butt cheek in my blog. So why does it hurt? I vacuum all the time and anyone who knows me can testify to that. Not a little pain but a sharp knock the breath out of you, WOW, pain. I have two rooms to go and it's not like I have a heavy machine it's an Oreck, so it's a whole 8 pounds. Come on what did I do wrong? Does anyone else ever have this p roblem, am I so unusual that's it's only me? Are my days of relieving stress with this household chore over? No I say NO I'm going to buck it up and finish the other two rooms. Wish me luck.