Ballistic stretching vs Dynamic stretching
The current mentality is to replace static stretching with dynamic stretching, which is stretching while in motion. This is a terrible name for what it is - stretching under eccentric load, which I'll cover in another post soon - because it can be confused with ballistic stretching. Here's an example of ballistic stretching: from a standing position, bend forward and touch your toes and return, ten times, as quickly as possible; the momentum will push you further than you could normally go, increasing the stretching of the muscle. This, paradoxically, is not what you want to do; that familiar sensation of "stretching" is a pain warning.
Where does the guy in this photo feel the stretch?
But is it worth doing? If you have the range of motion you need to run, why would you need more? I think the answer is that as one runs for years, one's range of motion even in the running stride diminishes and this leads to slowing and to injuries when trying to push the range of motion.
I have a set of about four dozen stretches I do, too many to discuss individually here, each learned from an experience with an injury. Coincidentally, it works out to about one per muscle involved in running. I don't do them for flexibility, however. I do them as a warning system of minor injuries. If you feel a stretching sensation, you already have a minor injury and you're probably so used to it, you don't even recognize it.
Here's the idea. If you rotate your arm at the shoulder as far as it will go in all directions, you probably won't feel any stretching. If you do the same thing at the hip, you will, because you've developed the muscles around the hip to provide stability for standing and walking. An infant's leg will bend fully in any direction, but that flexibility is lost starting when they learn to walk. But contortionists, who maintain the infant's flexibility, can still walk perfectly, because development of the stabilizing muscles does not preclude range of motion - we just tend to ignore it, because we don't need it.
Try bending your body through the full range of motion at each joint and you may find a number of tight muscles that could eventually lead to injury, though they might never be a problem. I hope my next posts will cover how to increase mobility and then how to strengthen the muscles that oppose the ones that are too tight and then finally how to incorporate all of that into running-related exercises.
Whew. I'm not sure I can cover all of that....