When planning an athlete's flexibility training you must also consider specific movement patterns, speed of movement, and loads which are not addressed with static forms of flexibility training.
Ideal methods in this case include full ROM strength training and isometric stretching which promotes flexibility-strength especially at end ROM, and progressive, dynamic stretches in which the athlete performs movements near and at end ROM at progressively faster speeds to develop flexibility-speed capabilities. These types of activities also reduce the difference between passive and active flexibility (flexibility deficit).
A low flexibility deficit promotes injury prevention. Static stretching promotes a flexibility reserve against unexpected movements beyond normal ROM, but does not affect the flexibility deficit. Full ROM strength training,dynamic stretches, and isometric stretching will increase both static (passive) and dynamic (active) flexibility.
All methods of flexibility training is not created equal. There are times an places where each method may be ideal.
In regard to static stretching before activity...
Static stretching has been shown to reduce power output in vertical jump tests. Therefore it is not recommended prior to activities which require any significant levels of power. It is also not systemic, but rather isolative in nature as a warm-up and therefore may be insufficient as a form of warm-up whereas dynamic stretches tend to be more full body exercise which increases systemic body temperature (based on sweating patterns) and can be performed in more sport specific manners in preparation for specific activities.
