PNF Stretching

| July 1, 2013 | Reply

PNF stretching is an advanced stretching technique that entails both stretching and contracting particular muscle groups in order to render improved flexibility and increased muscle strength. Its characteristics make it a truly effective way of expanding one’s suppleness, however, due to these very features, it is mostly aimed at comparatively experienced athletes.

PNF stands for Proprioception Neuromuscular Facilitation and its initial target was in fact to be a form of rehabilitative therapy for people who had suffered a stroke or paralysis; however, thanks to its proven effectiveness as such, it soon gained the attention of physiotherapists and fitness experts, being applied today as a method for increasing the trainees’ range of motion.

How PNF Stretching Works

In essence, a PNF stretch is a combination of sequential isometric and relaxed stretching (aka passive stretching) of the muscles. More technically, a PNF stretch makes use of the initial isometric contraction of the stretched muscle and the subsequent reduced ability of the muscle fibers to contract in resistance to a subsequent stretch; moreover, this technique employs the Golgi Tendon Organs (receptors which feed the body with information about the force that a muscle develops when contracted and send a signal to the spinal cord to ease off the stretch), inhibiting the contraction of the muscle through the lengthening reaction; that contraction during a stretch increases tension on the muscle, and the GTOs are triggered more actively compared to the activation coming exclusively from a stretch. Thus, when the contraction is ceased, the employed muscles are less vulnerable to contraction against another stretch, and that’s exactly the point that the PNF method “exploits” in order to work on the increased range of motion which follows the isometric contraction so as to achieve greater flexibility.

A typical PNF stretching routine requires performing the sequence described below for 3-5 times for a given muscle group, with a 20-30 seconds interval between the repetitions (for the definition of a repetition/sequence, see below: PNF vs Isometric Stretching). Yet, other physical experts claim that performing just a single sequence for a given muscle group is just as effective.

Obviously, in order for PNF stretching to be performed properly, the use of a partner is essential, since there isn’t another equally effective way for putting the needed resistance against the isometric contraction and moving the passive stretch to a further point.

PNF Stretching Exercises

Taking for granted that most PNF stretches are conducted with the help of a partner (who has to be an experienced instructor), there is no particular difficulty in that point. To get a notion of how PNF stretches are performed, go through the following examples (still, without skipping our Stretching Guide!):

  • Imagine the start of a typical passive (aided by a partner) hamstring stretch; you lie down on the floor with your legs straightened, and your assistant uses his / her shoulder to push, let’s say, the right one up, still straightened, to the direction of your head (so far, this is much like a passive stretch); once your leg has gone up for some degrees, approaching its motion range limit, your partner holds it in place; there, you start contracting your hamstring, like you want to push your partner away; after doing that for 5-10 seconds (without putting so much force – a 30-40% of maximum contraction is just enough), you let your hamstring relax for 2-3 seconds, and then, your partner (who hasn’t moved) pushes for another, deeper hamstring stretch (photo 1). For more hamstring stretches, click this
  • Stretch your leg up high on your partner’s shoulder and then contract your muscles by trying to move the leg down to the ground, with your partner providing an opposite force so as to prevent you from completing it; then let your partner push up your leg gently to a wider stretch.
  • Once you get the catch, you can carry out the following PNF stretch on your own: Sit down with your legs open and bend forward so as to approach your flexibility limit (as if you were executing a typical passive/static stretch); now, being stretched forward, tense hard (like you would do if you wanted to show off your muscles!) for approximately 10 seconds, either holding your breath or breathing slowly; when those seconds are over, breathe out and increase the stretch by bending deeper towards the ground, and you will have managed to conquer a wider stretch more easily (photo 2)! This is a pretty effective adductor stretch!

Holding the new, increased stretch varies in duration, being anywhere between 20 to 60 seconds.

Benefits

The positive aspects of PNF stretching are multiple, exceeding the normal stretching benefits. Therefore, performing stretches in PNF mode:

  • Can greatly increase flexibility, as it quickens and stimulates the neuromuscular mechanisms response while ensuring that both the antagonists and agonists get alternately relaxed and contracted. In fact, in comparison with simple passive or static stretching, studies (found here and here) show that PNF provides higher raise of ROM (range of motion).
  • Adds to the strength and of the employed muscles
  • Is beneficial for the stability of joints

  • Can significantly reduce the risks of a joint or muscle injury, provided that the exercise routine is performed correctly

What To Consider

There are some concerns involving PNF stretching. For example:

  • This stretching mode typically puts substantial stress on the muscle groups engaged and might, in some cases, actually increase the chances of a soft tissue injury; therefore, this type of stretching should be avoided by individuals whose bones are still growing (children, adolescents).
  • Apart from being rather peculiar while executing it, the contraction phase can also induce raised blood pressure as a result of the trainee holding his / her breath.

  • The usual employment of a partner, in order to guarantee proper execution of the exercises, makes this stretching model rather inconvenient at times.
  • Due to its demanding nature, PNF stretching should not be performed on the same muscle groups without an interval of at least 36 hours.

PNF vs Isometric Stretching

PNF stretching may initially appear to resemble to isometric stretching, but it is actually a method which somewhat merges that type with passive stretching, and the usual employment of a partner; also, in PNF, the contractions usually are held for a shorter period of time.

For a clearer view, keep in mind that most PNF stretching types make use of the sequence a. passive stretch, b. subsequent isometric contraction (against resistance while staying in the stretched position), c. relax for 2-3 seconds, d. final passive (or active) stretch (exploiting the bigger range of motion that is now “permitted” by the stretch receptors), which is also the beginning of the new sequence.

Special PNF Stretching Techniques

Apart from the basic model (known as the “hold-relax”) described above, there are several techniques of PNF stretches, with variations among them, such as the hold-relax-contract, the hold-relax with agonist contraction etc. It is self-evident that, if you finally integrate a PNF program in your life, the choice of those variations must be done by a trained instructor with respect to your needs, conditions and goals.

Photos & Videos

Watch the videos and photos below to get a better idea on PNF stretching:

 

 

PNF stretching - the mechanism

Photo 1- PNF Hamstring stretch

 

pnf adductor stretch

Photo 2 – PNF Adductor Stretch

Our Opinion

PNF stretching is a highly technical approach to stretching which can deliver remarkable benefits in terms of increasing the range of motion and improving your performance. Yet, whether or not this method is appropriate for novice athletes is a matter that should be determined by a fitness expert, in order to help them stay clear of unnecessary labor and trouble.

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Category: Types of Stretching

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