I think you should mention that for some people, stretching is not the solution and that it will deteriorate their posture. Some people need stretching, but most people I know need to strengthen their "overstretched" hip flexors. Many people can't do a single hanging leg raise. Check this site if you want to know more about the importance of hip flexors bit.ly/Unlock_Your_Hip_Flexor Report
You can strain or tear one or more of your hip flexors when you make sudden movements such as changing directions while running or kicking. Sports and athletic activities where this is likely to occur include running, football, soccer, martial arts, dancing, and hockey. In everyday life, you can strain a hip flexor when you slip and fall, for example.