I went to overtake a lorry that was stationary in a line of traffic, no cars were coming the other way, as I come around the back of the lorry I see a bus has stopped and car is overtaking it, there wasn't enough room for both of us, so we both do an emergency stop, I had trouble unclipping being caught totally off guard. I managed to unclip but fell slightly towards the lorry I had been overtaking, the lorry was just starting to pull away and it had one of those hooks on the trailer for wrapping rope around, this caught me just inside of arm around the tricep area and ripped all the way through to the flesh. Talk about pain!!!!!! I still had 6 miles of my commute to do, which was done through gritted teeth. What a mess my arm is in!! I can't help think how lucky I am that it was a bit warmer this morning and I was wearing a short sleeve shirt, god knows what would have happened if I had been wearing long sleeves and the hook had caught on that? dragged under the wheels perhaps?!?!?!? I feel like a right f_c_ing idiot, I'm usually so careful and aware of my surrounding when cycling!!!