What Is PNF Stretching?

Written by Alicia Racelis, PhD
Medically Reviewed by Ross Brakeville, DPT on June 29, 2025
7 min read

Proprioceptive neuromuscular facilitation (PNF) is a form of assisted stretching. It combines passive stretching with muscle contraction. First, your partner applies force to stretch your muscle passively. Then, while holding the stretch, you contract the same muscle.

Herman Kabat and Margaret "Maggie" Knott designed PNF at the Kabat-Kaiser Institute between 1946 and 1951. PNF was first used to help people with neurological conditions, but it can also treat musculoskeletal conditions.

Now, the concept is used for rehabilitation. PNF can help increase your range of motion (ROM) after an injury or surgery. The stretches may improve your passive and active range of motion. Athletes and nonathletes also use PNF to improve performance. Learn more to see if PNF can benefit your health.

You'll start with a passive stretch, meaning a partner helps you move your muscle into a stretched position. While holding that stretch, you contract the same muscle — that's the core of PNF. While a passive stretch involves help from a partner, a static stretch means you hold the stretch on your own for a period.

For PNF exercises, you choose a muscle to stretch. Holding the stretch position, you'll contract your muscle against the resistance from your partner. Then, you'll relax your muscle before repeating the same process.

A partner usually helps with PNF at first. You may learn to do it on your own in physical therapy or rehab. You can stretch using a strap or towel for assistance. Ask your health care provider about it. 

There are three PNF methods: contract-relax (CR), contract-relax-antagonist-contract (CRAC), and hold-relax-swing.‌‌

Contract-relax (CR) stretch

Also called the hold-relax method, CR stretch can help with your range of motion and flexibility. With CR, you'll passively stretch your target muscle. Then, you'll contract your muscle while holding that stretch.

The contract-relax exercise deeply stretches your muscles. The stretch also helps stabilize your muscle in the stretched position. That's because your muscle creates force during the stretch. You'll relax before you stretch a little further. Then, contract (squeeze) your muscle again. The contract-relax move sends signals to your nervous system.

As you activate your muscle in the stretched position, it adds stability to your joint. And your brain allows you to move a little further.

Some studies suggest PNF may help older people get stronger hips and ankles. But it's still not clear how PNF stretching affects muscle strength.

Contract-relax-antagonist-contract (CRAC) stretch

It's also known as the hold-relax-contract stretch. You'll focus on antagonistic pairs of muscles. The muscle you contract is called the agonist. The muscle that's relaxing is the antagonist. So, one muscle contracts, while the other relaxes. 

There's no passive stretch at the end. That means CRAC is one of the safest PNF stretches, as you're less likely to tear a muscle.

Hold-relax-swing stretch

This technique is not recommended for most people. The hold-relax-swing or hold-relax-bounce stretch has a higher risk for injury. The move combines dynamic (ballistic) stretches with static and isometric stretches.

Hold-relax-swing isn't suggested for beginners. You'll need excellent muscle control and strength to avoid injury. Usually, experienced athletes and dancers perform this stretch.

PNF stretches help lengthen your muscle-tendon unit. They do so by activating special receptors called Golgi tendon organs (GTO). They are proprioceptors that sense changes in muscle tension. The GTO helps improve flexibility and increase the range of motion.

Here are the benefits of PNF stretching:

Increase range of motion (ROM). PNF stretching may increase your ROM. Some studies show knee and hamstring ROM improved with PNF. And some reviews suggest your joint ROM can get better with PNF. But some studies report static stretching can also increase ROM.

Boost muscle flexibility. PNF may boost hamstring and lower leg (gastrocnemius) muscle flexibility. But it's unclear if PNF can improve flexibility for other muscles.

Boost muscle strength. Static stretching can lower your muscle strength before exercise. But PNF may prevent loss of strength before a workout. PNF stretches may also help you run, jump, and grip better. More studies are needed to know for sure.

PNF may also help ease lower back pain. One review showed a six-week PNF program helped chronic back pain symptoms. And the stretches may help your alignment and stability.

Here are some risks of PNF stretching:

Increased risk for muscle tears. PNF stretching can twist or tear your muscles. You can overstretch with PNF, which can pull your muscle. If you’ve never tried PNF before, ask a physical therapist or professional trainer. They can explain how to safely do PNF.

For example, the hold-swing-relax (hold-relax-bounce) uses dynamic (ballistic) stretches. These are static and isometric stretches. The methods come with a higher injury risk. 

Lower exercise performance. Multiple studies show stretching may reduce your exercise performance.

Studies on PNF stretching showed:

  • Lower jump height (but it's still unclear)
  • Reduced strength and power
  • Slower muscle activation times

Some experts don't suggest PNF before high-intensity exercises, weightlifting, or sprinting. 

Training and help needed. You may need to learn about PNF stretching. It isn't for beginners. And some stretches may require a partner. But if you can use a stretching strap, you may get similar results. One study showed PNF stretching was equally effective whether done with a partner or a strap.

PNF stretching may not help your muscles relax. One study found the stretches didn't relieve muscle stiffness in older adults.

To keep your joints moving, you can try these stretches.

Try a contract-relax stretch

This mild to moderate stretch can lengthen your muscle. Passively stretch your muscle before contracting it for 7-12 seconds. To stretch your hamstring start by:

  1. Laying on your back. Keep one leg on the floor and ask a partner to lift up your other leg. Keep your knee straight to feel your hamstring stretch.
  2. In the stretched position, isometrically contract your hamstring by pushing your leg back against your partner. Hold for 7-15 seconds. 
  3. Take a deep breath. 
  4. This contraction holds your muscle at a constant length. Relax your muscle for two to three seconds.
  5. Passively stretch the muscle again. This time, stretch the muscle a little more. This can help your range of motion. 
  6. Take a deep breath. Contract again for 7-15 seconds.
  7. Take a deep breath. Hold for 7-15 seconds.
  8. Relax the muscle for two seconds before trying to stretch a little further.
  9. Repeat this process three to five times, ending with the contraction, not the stretch.

Try a contract-relax-antagonist-contract stretch

You'll stretch your hamstring in the same position. Lay on the ground with one leg flat on the floor. Ask your partner to lift the other leg up. Keep your knee straight for a passive stretch.

  1. Once your partner lifts your leg into a passive stretch, hold for 7-15 seconds.
  2. Then, do an isometric contraction, pushing back against your partner for 7-15 seconds.
  3. Remember to breathe.
  4. Keep your knee straight to feel the stretch.
  5. Then, use your own strength to stretch a little further for 7-15 seconds — your partner can assist.
  6. Take another deep breath.
  7. Relax your muscles for two seconds with your partner holding in the new position. 
  8. Then, contract the muscle again by pushing against your partner for 7-15 seconds.
  9. Repeat this process three to five times, ending with the contraction, not the stretch.

Try a PNF triceps stretch

You can do this stretch anywhere. And you don't need a partner.

You can start this stretch by:

  1. Holding your arms above your head. 
  2. Bend your left elbow and hold your elbow with your right hand.
  3. Gently pull your left elbow behind your head. You'll feel your triceps (muscles underneath your arm) stretch.
  4. Take a deep breath and hold for 7-15 seconds.
  5. Do an isometric contraction by pushing your elbow back against your hand, and hold it for 7-15 seconds.
  6. Breathe.
  7. Then relax for two to three seconds.
  8. Repeat these steps three to five times, ending with the contraction, not the stretch.
  9. Stretch your right arm next.

Proprioceptive neuromuscular facilitation (PNF) combines passive stretching with muscle contraction. The deeper stretch may improve your range of motion, muscle flexibility, and muscle strength during your workout. Check with your physical therapist to prevent muscle injury and find out if PNF is right for you.

What best describes proprioceptive neuromuscular facilitation?

Proprioceptive neuromuscular facilitation (PNF) stretching combines assisted stretching with muscle contraction. It triggers your proprioceptive system through muscle activation. Your muscles signal your brain about position and movement. And your nerves allow a deeper stretch.

What is the principle of PNF?

PNF helps improve your muscle and nerve (neuromuscular) stability. The exercises help remind your muscles about daily movement. PNF can improve your range of motion and build strength. 

The stretches may also make your movements more fluid. This can lower your risk for muscle injury. Because a partner helps, you also get visual, verbal, and touch input. And this can help your communication and body mechanics.

What is an example of a PNF?

Stretching your hamstring is a common PNF move. 

  1. Lie down on your back keeping both legs straight. 
  2. Ask a partner (or use a stretching strap) to lift your one leg. 
  3. Keep your leg straight to feel the stretch for 7-15 seconds. 
  4. Take a deep breath.
  5. Then, squeeze (contract) your leg pushing against your partner (or stretching strap) for 7-15 seconds. 
  6. Take another deep breath. 
  7. Then, relax before repeating the stretch three to five times. And end with a contraction, not a stretch.