Proprioceptive Neuromuscular Facilitation (PNF): PNF takes advantage of Autogenic Inhibition. There are three phases of a PNF stretch. An initial static stretch is held for 10 seconds. This is the first phase. The second phase involves a contraction of the muscle being stretched (about 6 seconds). The 3rd phase is another static stretch held for 30 seconds. Essentially following a “hold-relax” pattern.
The most basic PNF stretch is the “Hold-Relax” which starts with a static stretch. The second step is a contraction stage, followed by the third step of another static stretch.
The next PNF stretch is termed, the “Contract-Relax” stretch. Step one is the static stretch. The second step is a contraction of the muscle being stretch within its full ROM (range of motion) of about 6 seconds. The 3rd step is a 30 second static stretch.
The third PNF stretch is termed “Hold-Relax with Agonist Contraction” and takes advantage of autogenic and reciprocal inhibition. As always, start with a static stretch for about 10 seconds. Now, contract with no movement for 6 seconds, then immediately contract the opposite muscle while your partner stretches the muscle being stretched. (If you are stretching your quads, flex and contract the hamstrings.)
Now, you can add another version of these PNF stretches termed, “Hold-Relax-Repeat”. You can guess by now what this is, right? Static stretch for 10 seconds, contract for 6 seconds, static stretch for 10 seconds, contract for 6 seconds, static stretch for 10 seconds, contract for 6 seconds and complete the stretch with a 30 second static stretch.