A doghouse in the yard is a great deterrent. Home invasions aren't usually random. Some seniors who have come from other countries don't trust banks, and end up keeping huge sums of money at home. If you have something valuable, keep it in the bank-not at home. Seniors aren't necessarily more likely to fall than younger people, but it seems that way because the consequences are greater for older people.
Orthopedic surgery is still a big deal-people do die from it or fail to regain original mobility.
Extrinsic causes include the fact that our environment tends to become very cluttered as we get older, and we're not as aware as we should be of ways to make that environment safer. It's a downward spiral. They develop a real fear of falling, so they'll walk less, attempt fewer things, and get less exercise. They'll become weaker and lose muscle tone. As a result, they become less independent, and it's extremely isolating.