Worst injury resulted in an 11" steel plate down the outside of my lower right leg and numerous screws in that and in the ankle on the inside. Please note that this story is pretty much a list of things NOT to do... I had tied up 3 calves for maybe the 2nd or 3rd time. 2 of them were acting really well, the other wasn't. I was brushing on them, and was in between the two gentler ones, when for some unknown reason, the other one decided to throw a fit. He was bucking around, and hit the calf in the middle hard, causing him to jump, and when he came down, his front leg slid down the inside of mine, breaking off the little bone that sticks out on the ankle. This apparently holds the whole ankle together, because when that went, the bone on the outside just above the ankle snapped clean through as well. Fortunately, the calves calmed down and moved away from me, so I crawled out away from them. My first instinct was to pull off my boot (a slip on red wing work boot), which probably made it all worse. I was alone, and this was before I carried a cell phone, so I had no choice but to crawl a couple hundred yards to the house, to call my wife to come take me to the hospital. I was down nearly three months from that one, and 12 years later, I still limp slightly when I'm really tired. That's not to mention the arthritis setting in. I was lucky to get a good orthopedic surgeon that did alot of athletes, too. The last time I saw him, 6 months after the surgery, he told me that when he first saw me, he'd have bet anything against me being able to walk in 6 months, much less the 3 months when I actually started walking.
Another not to do - I once broke my right thumb, just below the nail, trying to lead a half broke 1300# steer (one of my students when I was teaching). The moral of this story is don't hold the lead rope with your thumbs sticking out against thre rope - wrap them around it. It may not sound like much, but try buttoning your jeans with a broken right thumb... I had to duct tape the clippers to my hand that week...
And on the subject of scotch combs - a friend of mine had a brand new one of those with a regular comb on one side and a skip tooth on the other in his back pocket. His son's steer, who'd acted perfect in the ring, spooked coming out and went completely nuts. My friend got ahold of the halter and was trying to lead him, when the steer managed to kick him right on the comb - drove that skip tooth into his lower back, just above his belt, all the way to the hilt. I was trying to hang onto the steer at that point, so I missed the privelege of pulling it out...
A tetanus booster and a really sore spot for awhile left him with a cool scar, too.
DL, I'm pretty much with you on handling cattle. I can't say you can scratch all of ours in the pasture, but all of them will follow you anywhere for the promise of a few cubes, and any kind of bad actor won't stay around long. Life's too short to put up with that b.s.