stretching ... runners

Static stretching (stretch and hold) right before a workout has a negative impact on workout intensity.

ETA: Science says static stretching is not bad if you hold the stretches less than 60 seconds. (This is a 2012 meta-study that incorporates the results of all the earlier "Stretching yay!" "Stretching boo!" studies floating around.)

Static stretching after a workout or in between workouts can increase flexibility and help protect joints from injury. Like, I am working on increasing calf flexibility to fight PF and peroneal tendinitis; I do those stretches 3 evenings a week but run/bike/swim in AM.

Dynamic stretching, when you're in motion (I think foam rolling would apply here?), can be part of a useful warm up and cool down around a run.

I can't comment on a "tweaked hip." I usually go by feel, the difference between good pain (foam rolling a tight IT band) and bad pain (biking into a tree)...

What Cheshirecat said - stretch after not before. Before you can walk or run slowly to warm up, but stretching is for after you run.

static stretching after your run, dynamic warm-up before your run.