Emergency situations generally aren't planned. You can't tell yourself, "oh, I think I'll go out into the wilderness and break my leg today." I suppose you could, but I think you might have some issues at that point. This is why we prepare for the worst and hope for the best. In other posts, I've talked about training and gear, as well as proper mindset, but a lot of situations can be...well not avoided, but perhaps made better with proper communication.
First, let's talk about planning and letting folks know what you're up to. I do a lot of hunting and scouting, and there have been times that I've gone out alone to do these things. I've always let my friends and family know where I was going (provided coords or a map) as well as when to expect me. Most of the places I go are out of cell phone coverage, so there isn't an easy way for me to communicate back home. But I let my people know if they haven't heard from me by X time and date, then something is up. I've read too many sad news stories of folks getting lost and ending up dead because no one knew where to look, or that they had even taken off in the first place.
Second, invest in a good communication device. As I mentioned above, I hunt and scout in a lot of places that don't have cell phone coverage. I bought a device called the Delorme Inreach which allows me to send messages, gps coords, tracking, and emergency SOS anywhere in the world. It was a little pricey, but it brings peace of mind. Plus, the ability to stay in touch with loved ones is wonderful.
Bottom line, communicate, have a plan in place, and don't do anything stupid that will risk your life while you're out in the wilds. It could make the difference between life and death.