Proprioceptive Neuromuscular Facilitation

PNF, short for  Proprioceptive Neuromuscular Facilitation, is a stretching technique that help engage a larger range of motion (ROM) in just a few moments  (Hindle et al., 2012). This technique is great for pain reduction should a certain movement or ROM cause pain. While there is an ongoing debate, whether PNF is different than Muscle Energy Technique (MET), from our studies of both modalities, the instruction are very similar, one is more popular with physiotherapists while the other with osteopathy. For the purpose of this article, they are the same modality.

Before we would dig further into PNF/MET understanding and physiological effect on the body, it is important to note: Should you be unfamiliar with the method, do not try and engage it on your own, it can cause damage to your muscle tissue should it be done poorly. Find a professional that is familiar with the method when using it or trying it for the first time.

After finding the target muscle group, engage into a stretching position, and stop just before pain or discomfort are being felt. It is important to perform PNF with as little pain as possible to avoid injury. In some people, this painless position is not even considered a stretch, and that is perfectly fine, the benefit they will feel will be much more impactful. Once finding this position, simply ask your client to perform a contraction with the desired muscle group with about 10% of their force while you resist that contraction and maintain position of the body part. Hold that contraction for 5 to 10 seconds, release while maintaining position, and once fully relaxed move further with the stretch. Repeat those 3 – 5 times, and end with a light stretch  (Franke et al., 2015).

In the image above, you can see a PNF to add ROM to shoulder flexion. The pain free end ROM has been engaged. Force has been applied on the shoulder through shoulder extension while exhaling, meeting the resistance of the suspension trainers. After about 8 seconds, inhalation and relaxation occurred, during exhalation another step away from the anchor has been taken, forcing the arms into further shoulder flexion, stopping just before pain / discomfort occurs. Process will be repeated again, until a sufficient ROM has been engaged allowing to train better with lower risk of injury.

On the anatomical view, our muscles have 2 organs to prevent or allow motion through different ranges of motion. If you engage a motion that is too fast, or too strong, the body’s reaction would be to block the motion from occurring in order to prevent that motion from inflicting injury, the organ used in such case is the Muscle Spindle.

PNF, however, is accessing the opposite organ in the muscle, the Golgi Tendon Organ (GTO), unlike the Muscle Spindle, GTO instructs the body to release the tension from the muscle to allow a bigger ROM, during the contraction of the muscle, the GTO “recognizes” there is an attempt to access a certain ROM that would not inflict any injury, and sends signals to relax the muscle and enable the ROM that was not accessible before  (Hindle et al., 2012).

Muscle Spindle and GTO are the reasons you should be concentrated on the stretch, and make sure it is not used through painful or discomfortable ROMs, should you attempt to engage PNF while under discomfort, instead of triggering the GTO and allowing bigger ROM, you might be triggering the Muscle Spindle and causing the exact opposite.