23 Oct 2018

PNF – Fighting Fit or Fashionable Fad?

You’ve probably heard about the new fitness trend which is sweeping across gyms all over the world……PNF stretching is also known as resistance stretching. What exactly is it and is it good for you?

Is PNF merely a fitness fad or will it get you fighting fit with the flexible prowess of a gymnast?! Let’s start out by exploring the definition and concepts behind Flexology and PNF to see if anything resonates with you.

Proprioceptive – Pertains to a sensory receptor, primarily found in tendons, joints, muscles and the inner ear, which detects the position or motion of the body by responding to internal stimulus.

Neuromuscular – Relates to both muscles and nerves, with the neuromuscular junction being the nexus of a nerve and a muscle fiber. Neuromuscular transmission is simply the transfer of information from the nerve to the muscle.

Facilitation – Is the escalation of the response of a neuron to a stimulus after being stimulated.

So, that's what it stands for, now what does it all mean and how does it relate to you?

What is Flexology?

No, flexology isn’t a new religion but you may be excused for thinking that it is as people are flocking to it and singing its praises. It’s an idea that’s been around for ages but it’s only now coming to real prominence.

It’s widely recognized that body movement is an essential function of life, and keeping physically fit and active can only improve that life. In competitive sports and even with your regular gym workout, coordinated and precise movements are fundamental for success. Now that there’s a growing understanding of the part that sensory information plays in the central scheme of things, there’s been a huge shift in the fields associated with human movement control.

Flexology is the practice of assisted stretching, where a fitness professional or ‘flexologist’ has studied physical behaviours in relation to both simple and complex reflexes and can translate that into a stretching routine for you. That’s the commonly accepted meaning. As a discipline, the aim is to understand and interpret flexibility and the function it plays in physical fitness.

PNF stretching, in particular, is all about activating certain muscle groups and lengthening them out until they’re at peak flexing position, then gently pushing back on them. This provides a level of resistance which enhances the muscle action. That’s why PNF is also known as resistance stretching, it’s a layman’s term for the wordy mouthful that is the true definition of PNF. According to the Australian Journal of Physiotherapy, progressive resistance training increases strength.

Understanding Proprioception

So, what exactly is proprioception? Well, according to the Finland School of Information Sciences it’s when information about the body’s movement is transmitted to the brain, based on which, relative adjustments can be made. It actually provides feedback on the status of the body internally and lets you know where the various parts of your body are positioned in relation to each other and whether your body is moving with the required amount of effort. The neuromuscular sensory receptors (located in muscles, tendons, and joints) allow for a sense of position and movement in relation to forced action.

When you sit, stand, move or stretch your body with any physical exertion, it will respond by carrying messages from the brain (via the spinal cord) to the muscles and nerves. The nervous system provides the correlating link between thoughts and ultimate action by relaying these messages so quickly that you don’t even know it’s happening until you actually see movement.

The basic anatomical connection between the brain and body was first understood by a Scottish physiologist Charles Bell who described the ‘muscular sense’ as a closed-loop system where, “there is a circle of nerve; one nerve conveys the influence from the brain to the muscle, another gives the sense of the condition of the muscle to the brain”. Sixty years later in 1886, the English pathologist and anatomist Henry Bastian invoked the term ‘kinaethesia’ which comes from the Greek words, ‘kinein’ (move) and ‘aisthesis’ (sensation). He referred to, “the body of sensation which results from or is directly occasioned by movements…kinaesthesis. By means of this complex of sensory impression we are made acquainted with the position and movements of our limbs, by means of it the brain also derives much unconscious guidance the performance of movement generally”. Simply put, this means that our body moves and coordinates itself in concerted action when the brain and body work together.

Proprioception isn’t solely a physical property, but actually has both, a psychological and a physiological quality. Specifically, proprioception is the perception of body movement and position within a certain dimensional space. That basically mean, how you relate to your surroundings. Most proprioceptive information translation is an unconscious effect of your body’s inner intelligence. It’s similar to hardware and software on your computer. The hardware (which is your body) sends information to the software (your brain) to integrate and use.

It was an English neurophysiologist, Sir Charles Sherrington who introduced the concept of ‘proprioception’, derived from the Latin root ‘proprius’ (one’s own) and ‘perception’. Okay, so that’s the history and grammar lesson over for today! Now we get to explore PNF stretching in all its glory

What is PNF Stretching and Should I Do It?

PNF stretching is a particular technique which enhances muscle elasticity and has been shown, under certain circumstances, to have a positive effect on both active and passive range of movements. Manual Therapy from ScienceDirect reports that “methods for assessment and intervention is of vital importance in musculoskeletal rehabilitation”. PNF is supposed to be great for strengthening muscles and improving flexibility. It’s actually comparable to yoga in some respects as both results in similar benefits.

Although most ordinary body movements that you do in everyday activities are automated, conscious perception and focus is needed to learn complex skills i.e. like Tai chi or basketball. It’s basic common sense to know that you need to be aware of your surroundings. It’s pretty hard to stop the ball from hitting you in the face if you don’t realize the relative position of the ball. Which is why proprioception plays an important position in sports performance. Repeated tasks condition the body to behave in a certain way and it retains a type of muscle memory. When we make new neural programs, they’re transferred to the more fundamental regions of the brain, where they’re carried out faster and without as much effort.

According to the Journal of Human Kinetics, PNF is a practice commonly used for increasing range of motion and strength, and the belief is that repeated PNF stretching actually preserves this muscle memory. PNF relies on reflexes to produce deeper stretches with the benefit primarily being increased flexibility although there hasn’t been a whole lot of research into the science behind it yet. It’s worthwhile noting that apparently, PNF decreases performance in maximal effort exercises when completed prior to exercise. (Maximal Effort Method is defined as lifting a maximal load against maximal resistance and is specifically designed to improve strength.)

This is why PNF is so interesting. Stretching before and after exercise has been around forever and is widely recognized to be a good practice, but making stretching the actual physical exercise is a new notion. PNF stretching should be used to complement daily static stretches and has actually been shown to help athletes improve performance, including an effective increase in range of motion.

It stands to reason that understanding how the body works is key to understanding how to get it to peak performance level. Which is all anybody can ask for. Unless of course, you’re a superhero with mutant genetics, then you can expect your body to fly, turn invisible and deflect bullets, or something else incredibly cool!

Anyway, according to the Journal of Sport and Health Science, the role of proprioception in sports has been investigated (using different techniques) yet there are basic functions of human movement which are still up for debate. As with any form of exercise, you should approach it with caution and always consult a professional before embarking on a strenuous routine.

How Do I Perform a PNF Stretch?

Now we come to the actual performance aspect of PNF stretching. There are differing opinions of length of timing for PNF stretching but the literature I’ve read, particularly according to the International PNF Association and the National Centre for Biotechnology Information, indicates that this technique offers you the greatest benefits.

You start out by choosing the muscle group you wish to be stretched and then position yourself so that the muscles are flexed and under tension (known as a passive stretch). Then you simply contract the stretched muscles (also known as isometric stretch) for 5-6 seconds while your training partner - or a stationary object - applies sustained resistance. The pressure of resistance should be sufficient enough to prevent movement but not so much that it has you screaming in pain. It should be noted that the effort of contraction is only equal to the level of conditioning.

Then you need to relax the contracted muscle group and apply a controlled stretch for approximately 10 – 30 seconds. Allow at least 30 seconds for the muscles to recover and repeat the process around 2 to 4 times. This actually triggers the inverse myotatic reflex. Basically, it’s a protective reflex which prevents injury by calming the muscle.

Another common PNF stretch is also known as Isotonic stretching. Isotonic stretching is similar to the above scenario however instead of the hold-relax technique, you contract the muscle while moving. With this method, a trained professional would provide resistance as you contract the muscles and push your leg down to the floor in a hamstring stretch.

PNF Stretching Examples

The PNF Quad Stretch

While you’re lying down flat on your stomach, your flexologist puts one hand on your lower back while bending your leg upward, pressing it in towards to your buttocks. They stretch you out for approximately 10-30 seconds and you resist (strenuously as you want maximum resistance) for approximately 5-6 seconds, when you relax they then push the stretch out for a further 10-30 seconds. Give yourself 30 seconds to recover.

The PNF Hamstring Stretch

While you are laying on your back, your flexologist or training partner lifts one leg up and holds it straight up in the air, pushing it gently toward your chest. They maintain the stretch for approximately 10-30 seconds, after which you then push against the stretch for 5-6 seconds, then you simply relax. Then your trainer pushes the stretch out even further for 10-30 seconds. Rest and repeat for the other leg.

The PNF Chest Stretch

As you kneel of the floor with your back straight and your arms clasped tightly behind your head, your flexology trainer will hold you by the elbows and gently pull them backwards towards themselves for approximately 10-30 seconds. You then pull yourself forward to resist the stretch for approximately 5-6 seconds. Finish this stretch off with another 10-30 second stretch as your flexologist stretches your chest out even further.

Finally, when it comes to using PNF stretching to its maximum capacity it’s good to keep it simple and remember; contract, relax, breath and stretch. Your brain and body, the neuromuscular system and reflexes will actually do all the work. So, stretch yourself to your fullest potential but do so with caution and make use of the fantastic range of trained professionals at your disposal.