This video shows Dr. Evan Matthews explaining how to perform a proprioceptive neuromuscular facilitation (PNF) stretch of the hamstring. This is a very intense form of stretching that should only be done by intermediate to advanced exercise participants, and typically requires a skilled partner. Remember you should never stretch a muscle that has not been properly warmed-up.
Link to Dr. Evan Matthews website.
https://sites.google.com/site/evanmatthewseportfolio/home
