That running automatically results in hip and knee injuries used to be commonly believed in the medical community. Then this study (and others since) have changed that thinking. http://www.ncbi.nlm.nih.gov/pubmed/23377837

From my own personal experience, I know that running too much, too soon, before my body had adapted, resulted in various muscle strains and sore knees. But as I got smarter about my efforts, I discovered that all I had to do was allow time for my body to adapt to the workload. I also run mostly on softer trails and buy new shoes periodically and that helps too.

For me, there is nothing that can compare to running outside on a trail through the woods, especially if there are friends alongside.