[runking]

Keep in mind there maybe a dozen other things with your running that warrants your attention other then your stride length. I could be wrong, but I can't imagine altering your stride length will result in better performance. If you try to "force it" you'll probably see a decrease in performance. I'd suggest doing some hill bounds and such to improve on your forum and let the stride length follow a natural course. There are tons of very good quality runners who have horrible form. There isn't any harm in trying to improve your form, just let it come naturally. An artificial form might very well reap no rewards.