Proprioceptive Neuromuscular Facilitation(PNF)

What is PNF Stretching?

Proprioceptive Neuromuscular Facilitation (PNF) is a more 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, and as well as increasing flexibility and amplitude. In kicking martial arts, it is used before competition to increase movement amplitude.

Certain precautions need to be taken when performing PNF stretches as they can put added stress on the targeted muscle group, which can increase the risk of soft tissue injury. To help reduce this risk, it is important to include a conditioning phase before a maximum, or intense effort is used.

Also, before undertaking any form of stretching it is vitally important that a thorough warm up be completed. Warming up prior to stretching does a number of beneficial things, but primarily its purpose is to prepare the body and mind for more strenuous activity. One of the ways it achieves this is by helping to increase the body's core temperature while also increasing the body's muscle temperature. This is essential to ensure the maximum benefit is gained from your stretching. 

How to perform a PNF stretch?

The process of performing a PNF stretch involves the following. The muscle group to be stretched is positioned so that the muscles are stretched and under tension. The individual then contracts the stretched muscle group for 5 - 6 seconds while a partner, or immovable object, applies sufficient resistance to inhibit movement. Please note; the effort of contraction should be relevant to the level of conditioning. If your athlete is in top form, contraction can go over to 100%. If you are working with the beginner, maximal contractions are strictly disallowed, you shouldn’t go over 50%.

The contracted muscle group is then relaxed and a controlled stretch is applied for about 20 to 30 seconds. The muscle group is then allowed 30 seconds to recover and the process is repeated 2 - 4 times. Take a look  the table below.

1)	The athlete and partner assume the position for the stretch, and then the partner extends the body limb until the muscle is stretched and tension is felt.
2)	The athlete then contracts the stretched muscle for 5 - 6 seconds and the partner must inhibit all movement. (The force of the contraction should be relevant to the condition of the muscle. For example, if the muscle has been injured, do not apply a maximum contraction).
3)	The muscle group is relaxed, then immediately and cautiously pushed past its normal range of movement for about 20 to 30 seconds. Allow 30 seconds recovery before repeating the procedure 2 - 4 times.

Information differs slightly about timing recommendations for PNF stretching depending on who you are talking to. Although there are conflicting responses to the question of how long should I contract the muscle group for and how long should I rest for between each stretch, It is believed (through a study of research literature) that the above timing recommendations provide the maximum benefits from PNF stretching. Consider that athletes are different, and you can adjust this type of stretching according to your athlete condition and form. 

"Concise guide to sports injuries, 2^nd edition",Churchill Livingstone, Malcolm T.F. Read,  foreword by Bryan English