I was doing some research on flexibility and sports and I came across and intersting thought. More times than not it is assumed that more flexibility will help you perform at a higher level or avoid injuries. Check out this quote from Stretching Scientifically by Tom Kurz 2003.
Running economy has been associated with decreased flexibility. Stiffness of the calf muscles and achilles tendon enhances”elastic energy storage and return” during every running step, and the small range of motion of external rotation in the hip reduces the metabolic cost of the muscular activity needed for stabilizing the pelvis during long distance running (Craib 1996) Excessive mobility in the joints diminishes stability on the body, causing scattering of the forces acting on it. This in turn necessitates additional muscular tension in movements where parts of the body have to be stabilized to support heavy loads (Raczek 1991). Such scattering of forces-for example, caused by an excessively loose trunk at the moment of takoff-reduces performance in jumpiong(Wazny 1981b)
Just food for thought.