Pain in hip when running?

Pain in the posterior aspect (back) of the hip is a common problem in runners. There are a number of issues that can come into play, including pain stemming from the sacroiliac (SI) joint, or possibly from the musculature in that area. Those muscles include the piriformis and gluteal muscles. Recommendations include ceasing activity, using cold compresses or ice, and a stretching/strengthening program for the posterior hip and the core. If the pain resolves, it is likely muscular and related to overuse. If it does not resolve, I would recommend seeing a sports medicine specialist, such as myself.