Does running after working out your legs help?

No, definitely not. It would cause more damage than good.

After a workout, your muscles would be tired. You must give them time to recuperate/recover and provide them with protein and other healthy food to grow. If you are going to run after a workout, your muscles would get fatigued. They are already tired after the workout and if you run they will get fatigued. This can cause catabolism and your muscles can shrink in size instead of growing.

Running/jogging is a good exercise for your legs but do not do it before/after a leg workout. Do it on a separate day. Do not club it with your leg workout.