PNF is an acronym for Proprioceptive Neuromuscular Facilitation . PNF is not really a type of stretching but is a technique of combining passive stretching and isometric stretching in order to achieve maximum flexibility. PNF was originally developed by a physical therapist as a method of rehabilitating stroke victims. PNF consists of a muscle being passively stretched, then contracted isometrically against resistance while in the stretched position and then being passively stretched again through the resulting increased range of motion. PNF usually employs the use of a partner to provide resistance against the isometric contraction and to then take the muscles through its increased range of motion. Read More: Introduction of Stretching , Benefit of Stretching , Element of Stretching , Types of Stretching , Ballistic stretching , Dynamic stretching , Active stretching , Passive (or relaxed) stretching , ...