What the heck is PNF?

PNF is the latest acronym getting bandied about fitness circles, with people promising the stretching technique improves range of motion to therefore potentially reduce your risk of injury and boost performance.

PNF stands for proprioceptive neuromuscular facilitation and has been a firm favourite of physios for years but is only now starting to be used by everyday punters who want improved range of motion.

Quite different to static stretching, to do PNF you need a partner or a prop, such as a stretch band or wall, to help you pull your muscle into a deep stretch, then push against it for a few seconds before pulling the stretch further.

So if you were doing a hamstring stretch, sitting on the floor with your leg out in front of you, you could get a mate to push against your foot or use an elastic band to pull your leg back towards you. Once it's in a stretch, you'd then push with your toes against it for about five seconds to contract the muscle then pull it deeper into the stretch. 

"By pushing against something, it contracts that same muscle," explains Holly Brasher, spokesperson for the Australian Physiotherapy Association.

"It increases the stretch on the muscle that attaches to the bone because the muscle is now contracting, then when you relax and let it go you should be able to take the muscle to a further stretch."

Brasher says physios often use it when treating people who have had surgery or a soft tissue injury.

"Research has shown that PNF is more effective at increasing range of motion over static stretching," she explains. 

"You can do it on most of the muscles in the body, provided you can resist the action you are doing."

So it probably wouldn't work for a stomach stretch where you were laying on the ground and arching your back up, because it would be difficult to push against it, but it's great for triceps, calves and hamstrings.

"You can use props such as stretch bands or a wall or your hands but it does work better with a partner," Brasher explains. 

"If you were stretching triceps, you would take your arm behind the back of your head with the elbow pointing upwards. You pull on the elbow until you feel the stretch in the under part of your arm in the tricep," Brasher explains. 

"The PNF part would be holding your elbow with your other hand, then pushing the arm down towards the floor with your other hand resisting it. You are trying to return your arm to normal and your other hand is stopping you from doing it. Hold it for five seconds then let go and take it back into a further stretch again."

For each PNF stretch, you should complete three or four sets to try to get a little bit more range each time.  

"If you have adequate range of motion you might reduce your risk of injury overall," Brasher explains. 

But she warns not to do this type of stretching before a workout — do it once you're warm or in front of the TV at night when you're not about to go for a run.

"This sort of thing is best done during exercise or afterwards, or away from exercise," Brasher says.

"We recommend you do it at least twice a week to get some benefits."