my running rule, personal running rule, is to never static stretch before running, whether sprinting or not. I have found that since I STOPPED stretchign prior to running, I have not had ligiment issues ever.
For sprinting, I would warm up with a short 1/4 mile stride warm up run, a few mountain climber (dynamic stretch for hammie and calves) and then GET IT ON!
stretch real good after your workouts. Then all your lil connectors and stuff have good blood flow to them and you can reallt get your stretch on.
That is my personal experience.
FF