Here's my take!
Before or After? It depends on the purpose of the stretch. Performing stretches before a run can give the body the mobility to move with proper mechanics. After stretches I perform a series of light strengthening exercises to load the muscle in the new range of motion.* During a workout muscles tighten due to the chemical waste products produced and micro tears of the muscles during the run. Performing stretches after the run can help increase recovery by facilitating mobility.
Dynamic vs Static? Dynamic! Our body is 3 dimensional, by performing only static stretches encompasses part of the muscle. By performing motions in all 3 planes of motion more muscle fibers are included in the stretching. There is a time and place for static stretching but for athletes, dynamic stretches help to muscles warm up. Dynamic stretches is controlled movements not ballistic bouncing.
*Please see my post on strength exercises. Prior to a run, I don't use weight.
I perform these stretches prior to my run about 30 seconds and up to 2 minutes depending where my limitations are that particular day.
1) CALF STRETCH
2) HAMSTRING STRETCH
3) QUADRICEPS STRETCH
4) HIP FLEXOR STRETCH
5) GLUTEAL STRETCH
6) THORACIC SPINE MOBILIZATION
To improve rotation of the thoracic spine when the arm is swinging backwards - With L leg in front and R arm next to head, swing L arm behind the body.