Run less . Sounds counter-productive but the less you run the less likely you'll get injured. We see this in the office quite often. Triathletes will get injured from running, rarely from swimming or biking. Running is the hardest on the body of the three disciplines.
Runners tend to run all the time so they're just inviting injury.
Adding cross-training can really decrease you're likelihood of injury. The heart is stupid - it doesn't know the difference between swimming, biking, running, skiing, etc. By converting an easy run day or two into a biking or skating day, you still get the exercise benefits with less pounding on your body. It takes 7-8 days of inactivity before you'll begin to lose fitness . If you're injured and can't run, you won't lose fitness if you're idle for a couple days.