PROPRIOCEPTIVE NEUROMUSCULAR FACILITATION (PNF)

Wikipedia Definitions
Proprioceptive: http://en.wikipedia.org/wiki/Proprioceptive
Neuromuscular: http://en.wikipedia.org/wiki/Neuromuscular
Facilitation: http://en.wikipedia.org/wiki/Facilitation

Proprioceptive Neuromuscular Facilitation (PNF) is an advanced form of flexibility training that involves both the stretching and contraction of the muscle group being targeted. PNF stretching was originally developed as a form of rehabilitation, and to that effect it is very effective. It is also excellent for targeting specific muscle groups, as well as increasing flexibility and range of movement. It also improves muscular strength.

Contract –Relax PNF: It involves the therapist asking the patient to fire the tight muscle isometrically against the therapist's hand for roughly 6 to 10 seconds. Then, the patient relaxes and the therapist lengthens the tight muscle and applies a stretch at the newly found end range. This technique utilizes the golgi-tendon organ, which relaxes a muscle after a sustained contraction has been applied to it for longer than 6 seconds.