Runners - Technique and Surface matters
"Interestingly, when running is compared to walking, since you take fewer steps per mile when you run, the total amount of force that the knee sees is often less in smooth running than in walking. So technique and surfaces really do matter." Kevin Stone, MD
Do your heals strike the ground or do you land mid-foot? Do you typically run on hard surfaces or soft surfaces? How strong are your legs? Do you have stable or unstable knees?
With the right technique and shoes and choosing the right surfaces along with the right physical preparation, don't be afraid to start running. Running is a very efficient and beneficial form of exercise and when done properly it feels good.
In the article that I have referenced below, Kevin Stone, MD sheds some light on running and injury. It is worth the read.