I'd bet they probably have some abnormality too, but I don't think I'd expect them to have more issues. There's a lot talked about people getting injured in the gym, but people get injured a lot outside the gym, just for some reason people really fixate on in the gym injuries.

There's lots of research that indicates that frequent strength training significantly reduces your risk of injury in day to day activities, especially later in life. If I can deadlift 500 pounds, I'm not going to get injured lifting 100 pounds, but your general population could. If I've got 3 inches of muscle around my hips and increased bone density from resistance training, I'm not going to break my hip when I trip.

"Strong people are harder to kill" -Mark Rippetoe

Training reduces your risk of injury as long as you don't overtrain. Overtraining increases your risk of injury, but the injuries you sustain are training-related. For example you can really mess up your knees by running more than your body can handle or by running without warming up and stretching first. But the kind of injury you get is different from messing your knees up by falling over.