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Stretching can help you keep your joints and muscles strong, flexible, and healthy. It can also help you to improve your posture, reduce stress, and decrease pain.
Proprioceptive neuromuscular facilitation or PNF stretching is one form of stretching that is beneficial for improving your muscle strength and ability to move your joints with ease.
PNF stretching isn’t for everyone, though. Some of the exercises should only be done by advanced athletes or under the supervision of a professional trainer due to the potential risk of injury. Here’s what you should know about these techniques.
What is PNF stretching?
PNF stretching is a technique used to improve your muscle flexibility. It can increase both your active range of motion (the space in which you move a part of your body by using your muscles) and your passive range of motion (the area in which a part of your body can move when someone or something is creating the movement—like someone pulling on your arm) (Hindle, 2012).
PNF stretching is most often used by physical therapists and certified exercise trainers in athletic or rehabilitation settings. This technique can help you to (Hindle, 2012):
- Improve performance
- Rehabilitate injuries
- Restore range of motion
- Increase strength
It’s often used for people who have suffered soft tissue injuries or had invasive surgeries (Hindle, 2012).
PNF stretching techniques incorporate static stretches (stretches done without moving) and isometric contractions (contracting a particular muscle without moving the joint). It’s generally considered very effective, although surprisingly, there aren’t many studies looking at its effects (Behm, 2016).
All types of stretching have been shown to increase your flexibility and range of motion. However, sports medicine researchers aren’t yet sure which kind of stretching is most effective. Many studies have only monitored the amount of flexibility for a short time after stretching, say around 10 minutes, making it challenging to compare different types of stretching (Behm, 2016).
What are the benefits of PNF stretching?
Doing any form of stretching before exercise can be beneficial. You should customize the type of flexibility training you choose and the exact routine to your fitness level and the activities you plan to do (Behm, 2016).
One study found that PNF stretching significantly improved hip flexibility than static stretching alone (Gunn, 2019).
Another found that a single PNF stretching exercise increased the flexibility of the ankle and wrist joints and decreased muscle stiffness. However, the researchers didn’t see any significant differences between PNF stretching and the other types of stretching they looked at (Konrad, 2017).
Other research indicates that PNF stretching is effective in helping you to (Hindle, 2012):
- Improve and maintain range of motion
- Increase muscle strength and power
- Increase athletic performance after stretching
The researchers stressed that following proper protocol and practicing consistently were necessary to benefit from PNF techniques (Hindle, 2012).
6 benefits of stretching to make your body feel better
The 5 types of PNF stretching
There are several different types of PNF stretching techniques. They all involve stretching and contracting various targeted muscle groups in a specific order. Some, but not all, will require a partner.
The most common type of PNF stretch is the hold-relax technique. This involves passively stretching the target muscle and holding it for a few seconds. You’ll then contract (tighten) that same muscle without moving. Hold the stretch and the contraction for 10–15 seconds, then relax your muscle. Repeat this sequence while exhaling. You should be able to stretch further than before.
Another frequently used PNF technique is the contract-relax method. It’s almost identical to the hold-relax stretch. The difference is that instead of contracting the muscle without moving, the muscle is contracted while moving. This is sometimes called isotonic stretching. The contraction is released for a couple of seconds, and then the passive stretch is repeated for another 20 seconds.
A third PNF technique is the hold-relax-contract. This is also similar to the hold-relax, except that instead of relaxing into a passive stretch, you actively push into the stretch.
4. Contract-relax-antagonist-contract (CRAC)
The contract-relax-antagonist-contract (CRAC) method is similar to contract-relax but focuses on antagonistic pairs of muscles. These are opposite muscle groups, like your triceps and biceps or your hamstrings and your quadriceps.
In this stretch, one muscle contracts while the other relaxes or lengthens. The muscle that’s contracting is called the agonist, while the muscle that’s relaxing is the antagonist.
To perform the CRAC stretch, you should do the following:
- Perform a passive stretch, allowing your partner to stretch your muscle.
- Contract the specific muscle that’s being stretched for 7–15 seconds.
- Relax that muscle and contract the opposite muscle (the antagonist muscle) for 7–15 seconds.
- Relax your muscles for at least 20 seconds before doing another PNF technique.
The CRAC method is considered one of the safer PNF techniques since there is no final passive stretch.
Advanced athletes may sometimes perform the hold-relax-swing, also known as the hold-relax-bounce. This technique involves combining static and isometric stretches with ballistic or dynamic stretches. This approach can be dangerous for beginners and should only be done by dancers or athletes with a high level of muscle control.
The hold-relax-swing is similar to the hold-relax technique. The difference is that the ending passive stretch is replaced with a moving (dynamic or ballistic) stretch. This uses a swinging or bouncing motion to stretch the muscles further.
Tips and techniques for getting started with PNF stretching
No matter what type of stretching you choose, it’s vital to start slowly to avoid injuring yourself. This is especially true if you are new to advanced stretching techniques or have a history of injuries. You may want to see a professional trainer at first to make sure you can perform PNF stretches safely.
4 types of stretching and their benefits
It’s important to remember that the old adage, “no pain, no gain,” does NOT apply to PNF stretching. One study looking at the optimal intensity of PNF stretches found that participants who stretched more intensely had higher pain levels afterward, but this did not result in more flexibility. Repeated high-intensity stretching can cause pain and injuries. The researchers recommended working up to moderate-intensity in order to safely get positive results (Lim, 2018).
You also may not want to use PNF stretching techniques to warm up right before a competition. Researchers found a slight reduction in performance for 3–5 minutes post-stretching. However, studies that looked at performance more than 10 minutes after stretching found that any performance changes were trivial unless the stretching routine was extreme (Behm, 2016).
Is PNF stretching safe?
Despite its potential effectiveness at increasing your flexibility and range of motion, PNF stretching isn’t for everyone. For many of the PNF techniques, a partner is required to do them safely. There is also a high potential for muscle or joint injury if the stretches are done incorrectly (Behm, 2016).
Several of the more advanced PNF techniques, such as the hold-relax-swing, are only for experienced dancers or high-level athletes.
PNF stretching should not be done by children or teens since they may have a higher risk of developing tendon and connective tissue injuries.
- Behm, D. G., Blazevich, A. J., Kay, A. D., & McHugh, M. (2016). Acute effects of muscle stretching on physical performance, range of motion, and injury incidence in healthy active individuals: a systematic review. Applied Physiology, Nutrition, And Metabolism, 41(1), 1–11. doi: 10.1139/apnm-2015-0235. Retrieved from https://pubmed.ncbi.nlm.nih.gov/26642915/
- Gunn, L. J., Stewart, J. C., Morgan, B., Metts, S. T., Magnuson, J. M., Iglowski, N. J., et al. (2019). Instrument-assisted soft tissue mobilization and proprioceptive neuromuscular facilitation techniques improve hamstring flexibility better than static stretching alone: a randomized clinical trial. The Journal Of Manual & Manipulative Therapy, 27(1), 15–23. doi: 10.1080/10669817.2018.1475693. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6338275/
- Hindle, K. B., Whitcomb, T. J., Briggs, W. O., & Hong, J. (2012). Proprioceptive neuromuscular facilitation (pnf): its mechanisms and effects on range of motion and muscular function. Journal Of Human Kinetics, 31, 105–113. doi: 10.2478/v10078-012-0011-y. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3588663/
- Konrad, A., Stafilidis, S., & Tilp, M. (2017). Effects of acute static, ballistic, and PNF stretching exercise on the muscle and tendon tissue properties. Scandinavian Journal of Medicine & Science in Sports; 27(10): 1070–1080. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5479471/
- Lim, W. (2018). Optimal intensity of PNF stretching: maintaining the efficacy of stretching while ensuring its safety. Journal Of Physical Therapy Science, 30(8), 1108–1111. doi: 10.1589/jpts.30.1108. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6110207/
Dr. Steve Silvestro is a board-certified pediatrician and Senior Manager, Medical Content & Education at Ro.