PNF is an acronym for proprioceptive neuromuscular facilitation. This is a type of flexibility training that is unique in that it requires a partner or an external source of resistance to be performed correctly. PNF stretching involves both stretching and contraction of the muscle group being worked. This form of stretching was originally developed as a type of physical therapy but has been found to elicit gains in flexibility.
Passive Stretch
A passive stretch is one where you assume a stretching position and hold it with some other part of your body, or with the resistance of a partner or some other apparatus. This is the first stage of a PNF stretch and is a type of stretch that most people are used to performing.
Isometric Stretch
Isometric stretching involves the resistance of muscle groups through isometric contractions or tensing of the stretched muscles. This is usually accomplished by assistance from a partner or using a wall or some other type of immovable object to provide resistance. This type of stretching also plays a major role in PNF stretching.
Performing PNF
This technique, which is sometimes referred to as the contract-relax method, is the most common type of PNF stretching. After assuming the initial passive stretch, the muscle being stretched gets isometrically contracted, or pushed against resistance for 10 to 15 seconds. After a short relaxation of about two to three seconds, the muscle then gets immediately subjected again to a passive stretch, which should stretch the muscle even farther than the first passive stretch. After another relaxation period, the technique can be performed again.
When to Perform
PNF stretching should be performed after some sort of warmup and never when your muscles are cold. Significant gains in flexibility are usually made after exercise once the muscles have been warmed up and have been put through some sort of physical activity.
