Since there seems to be a lot of threads being started about flexibility, I thought it would be nice if we could outline where specific muscle tightnesses manifest themselves in terms of injury and flawed technique. So far I have:

Tight quads/IT band/hip flexors:
-lack of knee lift
-inhibition of glutes
-hamstring pulls
-reduction of hip height

What about hamstrings, glutes, hip rotators, groins, etc?

With groins, the occurrence of injuries aren’t associated too much with flexibility issues but are more related to groin strength.

There was a study done among professional hockey players where there was a greater occurrence of injury in the players with weaker groins. All the players involved had relatively similar groin flexibility.