If there’s one thing the media (social media in particular) has taught us, it’s that everyone has an opinion on everything. It’s become frighteningly easy for people with a limited understanding of a topic to disseminate their opinions on that topic to large audiences. We need look no further than the likes of Dr. Oz, whose masquerade of a TV show has been shown to follow scientific evidence less than half the time. Unequipped with a strong science background, the general population readily accepts and even swoons over poorly supported, sometimes dangerous, and downright false statements provided by these “authorities.”
In the health and fitness world, it’s become increasingly clear that there are a number of practitioners who have developed very strong and vocal – yet woefully misinformed – opinions. Their opinions often extend beyond their scope of practice to the experience of pain and the relationships between pain, inflammation, exercise, posture, movement quality, muscle balance, and muscle function.
To help address these myths and misconceptions, we at Physio Network gathered a panel of three hybrid physical therapist/strength coaches to answer some questions about pain, exercise, and movement in a roundtable format.
Physio Network: What is “pain science?” What is it not? Why is it important/useful/beneficial and for whom?
Jarod Hall: Simply put, “pain science” is nothing more or less than the scientific study of the experience of pain. Every person’s experience of pain is unique. Pain science attempts to understand the role of peripheral tissue injury, inflammatory cascades, nociception (the transmission of chemical, temperature, and mechanical pressure danger messages to the brain), neurophysiology of nervous tissues/the spinal cord/the brain stem/various areas of the brain/glial cells/etc, the immune system, emotions, perceptions, expectations, beliefs, social health, and much more in each person’s individual experience of pain.
Traditionally, pain and injury have been approached through a purely biomedical lens, which in a nutshell views all pain as originating from a definitive tissue injury, inflammatory process, biomechanical overload, and damage to anatomy. “Pain science” views people as complex living organisms that experience pain as an output based on a perceived need for protection. This need for protection arises from the brain’s evaluation of countless factors. These factors include physical, psychological, emotional, and social components, as well as beliefs, expectations, systemic health, and genetic predispositions.
Sadly, there is a common misconception that “pain science” is some sort of specific intervention and that you can “pain science” someone out of pain. However, as described above, pain science isn’t an intervention or something you apply to patients. It is simply the study of pain, from which evidence-based clinicians should take the findings and use them in any meaningful way they can to better serve the people in pain they interact with. If this sounds a little abstract, we’ll give plenty of examples below.
Approaching working with people through a lens of “pain science” does not mean to simply sit down and talk to them about pain – or that pain is “all in their head.” Instead, it recognizes the complexity of pain and opens several more avenues to explore and opportunities to modulate that person’s pain, increase their locus of control (how much control they feel they have over their pain), empower them, and get them moving.
Sam Spinelli: Pain science is often viewed as this weird intervention that’s done with people trying to talk others out of pain, telling them it’s all in their head. Pain science is often thought of as being separate from the rest of research/science. Let’s set the agenda straight: that portrayal of pain science is far from the truth. If that was your experience, it was notappropriate. We hope this article helps change your feelings on the subject.
Pain science, which we should really call the science of pain, is the collective embodiment of our current knowledge of pain. Much like physics is the area of science that studies how the universe works, pain science is the area of science that looks to understand how pain works, how we can affect it, and what matters with it.
Since pretty much every living person experiences pain and pain impacts how we live our lives, understanding pain is important. Most people will seek medical care for pain and even make life decisions based on pain. These decisions obviously impact society as a whole. Better understanding pain, even if only on a rudimentary but accurate level, can greatly benefit us in daily life. We can stop being concerned about small details, know which things will take care of themselves, and understand what we should worry about or focus on addressing.
Tim Rowland: ‘Pain science’ is simply an acknowledgement of the complexity of pain and the understanding that pain is influenced by a number of different factors (bio-psycho-social). It is the realisation that pain cannot simply be explained through biomedical means alone.
As a strength and conditioning coach working with athletes, pain science reminds me that if an athlete has significant knee pain after a collision, and they’ve injured their MCL in the past, this pain response might be heightened because of their past injury history; that the rugby player with chronic low back pain might feel more pain when he’s more stressed and tired; that the guy who’s tough as nails might actually have significant tissue damage even if he tells you he’s okay in the heat of a game.
It is notthat pain is ”all in your head.” It is just that pain is processed by the brain and your pain experience is determined by a myriad of factors. These factors include (but are not limited to) beliefs and expectations, stress, sleep, tissue damage, past injury history, mood, and level of social support.
It is important for both the patient/athlete as well as the coach/physio to have a grasp on pain science. The physio needs to understand it in order to make better decisions on how to manage the athlete, and the athlete will benefit from knowledge in this area because they’ll better understand what’s causing or contributing to their pain experience.
For example, a relatively common chronic injury in high-level athletes is tendinopathy. A big part of managing this condition is to ensure the athlete understands that pain does not necessarily equal tissue damage, and that their pain levels might be amplified due to the area being “hypersensitive.” Rehab programs for tendinopathy often require the athlete to push into small amounts of pain to sufficiently load the tendon tissue for positive structural adaptation. The understanding that pain does not equal damage helps the athlete buy into the program.
PN: Can pain be boiled down to faulty movement mechanics, improper muscle activation, muscle dysfunction, and postural aberrations?
JH: The approach of classifying movement, posture, and muscle function as good/bad or functional/dysfunctional depends on a big assumption. That assumption is that there are reproducible and accurate ways to determine optimal movement, posture, and muscle function. In reality, all available evidence to date shows no formally agreed upon example of objectively good posture – or what objectively good posture would be beneficial for if it could even be agreed upon.
The argument of optimal posture fails to take into account the wide degree of anatomical variation between individuals, as well as the influence of emotion and cognitive factors on posture. That’s right: people tend to adjust their posture based on their mood alone! Moreover, the argument assumes that static position will dictate dynamic function and that postures deviating from “optimal” will lead to tissue damage and pain – rather than beneficial adaptation, which the body is so good at.
We can create the same false dichotomy for movement mechanics and muscle function. Yet when we look at the research we see that muscle function and movement mechanics are tremendously variable between repeated bouts of the same activity (here, here, here, here, and here). In fact, it may actually be beneficial to have variation in movement for brain mapping and motor learning as well as load distribution across a wider range of anatomy (to protect against injury). We see that people with chronic pain tend to have reduced movement variability and are “trapped” into moving the same way over and over again (here, here, here, here, and here).
As mentioned above, pain is incredibly complex. Biomechanics, muscle function, and posture can certainly play a role at times in many people’s pain experience. However, reducing pain down to only these factors is at best a complete misunderstanding of what may be leading to pain. At worst, that simplistic line of thinking can snowball down the path of subpar or even failed medical management.
SS: It sure would make our lives simpler if things were as straightforward as good and bad movements and if bad movements were the cause of all our aches and pains. Unfortunately, it’s not that simple. Humans love to create dichotomies, but the difficulty is that these things usually exist on a spectrum and depend on context.
When it comes to many of these commonly accepted ideas (good/bad movements, muscle imbalances, etc.), they’re not actually defined objectively. They’re just someone’s opinion. For example, what one person considers a good squat another may view as a bad one. We see this when we look at how Olympic weightlifters squat (with substantial forward translation of the knee) versus the idea that the knees shouldn’t go past the toes. In this case, there’s no set definition of good or bad, and there’s no evidence to support specific standards. When we dichotomize issues in this way, it removes the need for critical reasoning, which is the easy way out but not necessarily the correct one.
If we look at muscle imbalances, what makes an imbalance? How is it measured? What is the standard for balance versus imbalance? What happens if it’s not balanced? People will often selectively choose muscles or joints to apply these notions to as it fits their beliefs and bias, but that isn’t how science works. To figure out what actually matters and what doesn’t, we need to be critical and challenge the status quo. Instead of calling it a muscle imbalance, perhaps someone just needs to work on a given muscle because they need it to be stronger. Spend some time working with people who have spinal cord injuries, extreme scoliosis, or amputations, and you’ll begin to see the flaws in many of these arguments.
TR: Pain can’t be boiled down to any one factor! There are a multitude of different variables that interrelate to contribute to someone’s pain experience. Being a strength and conditioning coach myself, I liken the statement “pain is caused by x” to “injury is caused by x.” You can’t blame one factor alone for causing an injury.
For example, an ACL injury might result from high acute training loads placed on someone with poor valgus control and a narrow intercondylar notch width, when they’ve concurrently had several days of poor sleep quality. Maybe if the same person with a narrow intercondylar notch width had better knee control and managed their training loads better, they might not have gotten injured.
As you can see, there are lots of factors at play when an injury occurs. The same line of thinking applies to pain. For example, imagine a client does some heavy deadlifts in their gym program one day and feels fine. They have them programmed again one week later, but in that week a good friend of theirs injures their back when deadlifting, they do some reading about discs “slipping”on the internet, they come into their next deadlift session a bit stressed and tired from work, and they feel something a bit “off” on one rep. All of these factors could result in the client experiencing some pain – especially if they’re worried about their back! Without the incident happening to their friend, and without the reading they did about discs “slipping” and how vulnerable the back is during deadlifts, they might not have experienced pain at all.
Alternatively, on an inter-individual scale, two different people can follow the exact same training program and execute the exercises in the exact same way and one may end up experiencing some pain while the other does not. How does a biomechanical model of pain explain this? Furthermore, how does a biomechanical model explain any of the following:
- Phantom limb pain
- Pain in someone with a textbook perfect scan with no inflammation
- Pain in someone with “perfect” mechanics (whatever that means!)
Having said all this, it is important to note that biomechanical factors can certainly be part of the many contributing factors to pain. It’s just unfair to say that pain can be boiled down to biomechanical factors alone.
PN: When do biomechanics matter? When should movement be “more good?”
JH:Biomechanics become more important in three instances: (1) when load increases, (2) when optimizing high-level physical performance, and (3) when there’s true acute tissue injury. The simplest way to view this paradigm is through tissue homeostasis and the so-called “envelope of function.”Activity can occur either below the envelope of function, within the middle and upper limits, or above:
- Activities far below the envelope of function cause no adaptation. They can even lead to atrophy along with reduced load tolerance and force production capacity.
- Activities approaching the middle and upper limits of the envelope of function lead to positive adaptations. They improve tissue loading tolerance and capacity. Optimal training and rehab occur in this zone.
- Activities that exceed the envelope of function lead to tissue overload and potential injury, depending on the volume and speed of overload.
To illustrate this concept further, let’s use two commonly cited examples of poor biomechanics in practice: knee valgus and lumbar flexion.
Knee valgus is often considered a pathological, unhealthy, and inefficient biomechanical flaw. Yet this movement of knee valgus has to be examined in context. In an unloaded squatting or stair stepping motion, the tissues of the knee (joint, muscle, ligaments, tendons, fascia, etc.) can easily tolerate the load placed on them with no problem. These tissues are incredibly strong, so this motion and load is well below the envelope of function.
Now, if we add external load (by adding a barbell to the back) or increase the total volume (by walking up and down several flights of stairs), we can shift total demand on the tissues towards the upper limit of the envelope of function. We call this the “zone of supraphysiologic loading.” If we do this correctly, it will lead to a positive adaptation. The tissues become stiffer, thicker, and more resilient. However, suppose we were to jump off of a house and land in knee valgus. This huge spike in loading would likely push the tissues to the far end of the envelope of function, creating a detrimental overload applied too fast for adaptation to occur.
Clearly, context is king. Contrary to popular belief, knee valgus is not inherently bad. Huge spikes in loading with the knee in valgus can certainly put you at increased risk for knee injury, though.
Lumbar flexion is another motion that is often labelled “bad” or “off limits.” This belief stems from several biomechanics studies that have demonstrated that sitting, forward bending, and lifting with a rounded and/or rotated spine appear to increase load on spinal discs. In one popularly cited study of cadaveric pig spines, repeated flexion-extension cycles under load resulted in an increased rate of disc herniation.
The problem with these broad sweeping generalizations is that they fail to examine what the actual loading capacity of a spinal disc is. Nor do they consider that discs can adapt over time, discs need load for normal health, and that disc bulges have a very poor correlation with pain. The lumbar spine has the inherent capacity to bend forward, flex, rotate, extend, side bend, and tolerate extreme amounts of compression. To classify one of these movements as inherently bad assumes that evolution’s blessings of lumbar range of motion were wrong.
Again, we have to examine movement in context. Bending forward to tie your shoes is an example of lumbar flexion that is significantly below the loading threshold. It does nothing good or bad to the tissues in the lumbar spine. It is just moving within a normal range of motion in the body.
Once again, with lumbar flexion we can work towards the upper end of the envelope of function with progressive loading of submaximal deadlifts or Jefferson curls. To create positive adaptations in tissue strength and loading capacity, we simply increase the load and volume over the course of several weeks and months. What we’re not talking about here is lIfting a very heavy object off of the floor with a twisting and jerking motion from full lumbar flexion without training or preparation. That right there would be a great way to push the tissues past their loading capacity and lead to injury.
To recap, biomechanics become more important as load increases, when considering maximal force production and high level physical performance, and in the case of true acute tissue injury. We cannot consider the relative importance of biomechanics without first considering the specific scenario of interest.
SS: Biomechanics always matter, however, how much they matter differs based on the situation. Biomechanics helps us understand how much stress or challenge will be put onto different tissues, but it doesn’t tell us how much stress or challenge those tissues can currently handle. A good example is aging and the ability to squat.
Biomechanics will highlight the positions in which the low back, hip, and knee will be most challenged. But when we look at a wide range of people, we find some are unable to tolerate much forward knee translation, lumbar flexion, etc. (These are typically the people who stopped doing these activities somewhere along the way.) In contrast, when we look at people in southeast Asia, it’s very common for them to squat while eating, conversing, or going to the bathroom. These individuals can do so with a forward knee position and lumbar flexion – exactly the same positions that the others could not handle.
We can use biomechanics to alter the stress a tissue experiences, but this decision is relative to the needs of each person. For example, when picking up something from the ground, we have a wide range of options, and each option challenges the back, hips, knees, and ankles differently. Depending on how much load tolerance you have across these structures, you will adopt a different option. If your knees do not have enough load tolerance for a squat style lift, you may go with more of a hinge or stoop style – or vice versa.
It comes back to requiring more critical reasoning and not being able to make overarching claims across all of humanity. Humans are amazing and adaptable; sweeping generalization do not apply to everyone.
TR: I’m going to steal my answer here from Greg Lehman. For pain and injury, biomechanics likely matters morein three instances:
- During high load activities (e.g. maximal back squatting or maximal effort cutting/side-stepping). Reason being, when an external load exceeds the ability of tissue to tolerate stress, an injury might occur; and the wiggle room for tissue overload is much lower in high load situations.
- When there is little time to adapt. There are certainly positions and postures that place more stress on certain tissues than others. For example, significant forward knee movement during squatting places greater stress on the anterior knee (e.g. patellar tendon). However, this does not mean that squatting this way will cause anterior knee pain. If a person is only squatting a couple of times a week, the structures in this area might simply be able to adapt to the stress imposed upon them without resulting in pain. However, if that person was to begin squatting every day, this gives these structures less time to adapt and therefore they are more likely to become overloaded. In this instance, squatting in a way that puts less stress on the anterior knee might help prevent anterior knee pain from developing.
- When psychosocial factors have been assessed and appear to be contributing little to the person’s pain experience.
In the presence of pain, I don’t think movement can be “more good” or better. However, I do think movement can be alteredto reduce stress on different tissues if it appears that the tissue/structure is sensitised. For example, you could do reverse lunges, keeping the shin more vertical, instead of forward or walking lunges to take stress off the anterior knee. This will help desensitise the area while still allowing for a training stimulus. And graded exposure to a similar movement pattern may also help make the original movement pain-free sooner.
It should be noted that for performance, biomechanics does matters a lot. There are certainly more biomechanically efficient ways to execute certain movement tasks such as sprinting, jumping, and throwing.
PN: Are movements/exercises inherently good or bad?
JH: No movement or exercise is inherently good or bad on its own. Movements and exercise are completely neutral tools to be used in the right way, by the right person, at the right time. The beauty of the human body is that it was designed/evolved to have an incredible capacity for adaptation. When we load it with sub-threshold loads, it tends to get stronger over time.
To claim a movement is bad infers that we know exactly what movement is good. It also infers that we understand completely how all pain and injury occurs and the exact biomechanical detail that is occuring within every aspect of that movement. Yet, if you ask any exercise biomechanics researcher, they will be quick to tell you many things we thought we knew about human movement were overly simplified or flat out wrong. Additionally, there are still lots of unknowns about how the body functions and adapts to different loads and movement scenarios.
In practice, we may see that a certain movement seems to aggravate an injury in most people most of the time, but this does not mean that this movement is “bad,” unhealthy, or wrong for other people at other times – or even that same person at some point in the future. Individual anatomy and injury history are likely the more important determinants of what exercises may be more or less “good” for a specific person at a specific time.
For example, it may not be a good idea to work on aggressive ankle inversion strengthening three days after an inversion ankle sprain. Yet that exercise wouldn’t be an issue in someone with a healthy ankle. It may not be a good idea to work on wide-grip, full-range of motion barbell bench press in someone who has a flared up biceps tendinopathy, but this exercise likely wouldn’t bother someone with no shoulder issues. It might not be a great idea to work on Jefferson curls in a person who has an acute disc herniation, but it may be good idea to progressively load the Jefferson curl over a long period of time to build strength and tissue loading tolerance in a person with no current disc pathology.
When looking at exercise and movement, we have to peel our minds away from good/bad dichotomies. We have to start looking through the lens that understands human tissues adapt to progressively applied loads. We should select exercises that make sense for the specific person in front of us and are directed at their specific goals.
SS: No, there are no good or bad movements, just ones you’re not currently prepared for. Over the course of time, there have been many exercises and movements that have been vilified – deep squatting, bench press, lumbar flexion, behind-the-neck exercises, burpees, etc. As we learn more about the movements and humans in general, we see that it’s not a simple good or bad, but rather a “currently appropriate” or currently not. For most people, many movements can be built towards with proper graded exposure and sufficient time. It’s just a matter of whether it’s a goal for you and if you’re patient enough to work towards it.
TR: In short, no. Some exercises might have a higher risk:reward ratio than others (like the old behind-the-neck press), but exercises aren’t inherently “good” or “bad.” It’s their application that is more often the problem.
Let’s take the behind-the-neck press as an example. For someone with great shoulder mobility, with no prior shoulder issues, who is an advanced trainee looking to optimise their anterior deltoid development, it’s a good choice for an exercise. Conversely, for someone with poor shoulder mobility and a history of shoulder issues, who has only been training for a year in the gym, it’s probably a bad choice. Or at least there are a lot of better choices!
Again, exercises aren’t inherently good or bad. They’re just tools to help provide a certain stimulus to the body. A certain exercise can however be a good or bad choicefor an individual, depending on their mobility, injury history, goals and level of resistance training experience. Like a lot of things in the rehab and fitness realm, it’s context dependent. They can’t be judged as good or bad without considering the person who is doing them and how they are programmed. Fit the person to the exercise, not the exercise to the person, and program it sensibly. Follow these steps and you will rarely run into any issues.
PN: What are the biggest misconceptions you see about pain and/or pain science?
JH: I see three big misconceptions about pain: (1) pain is often viewed as an input to the brain from the system rather than an output by the brain in response to threat, (2) the degree of tissue damage is often assumed to be directly proportional to the degree of pain experience, and (3) more pain equals a worse injury. We need look no further than examples of phantom limb pain to see that tissue damage itself is not solely responsible or even necessary for the experience of pain.
Regarding pain science, the most common misconception I see is that pain science is often viewed as an intervention or a “camp” of people. This immediately falls prey to creating tribalism and unwillingness to learn, as people have a tendency to put up a defensive nature when encountered by the “other camp.” Pain science is nota camp or an intervention. Pain science is simply everything that science tells us about the experience of pain and how we can use that information to help people in pain through physical, psychological, and socially focused interventions.
SS: When it comes to pain, the biggest misconceptions I see are that pain is bad and that it equals tissue damage. Pain is generally more of a threat perception than it is an actual measure of tissue damage. Getting people to understand that can be freeing when they feel daily life’s normal aches and pains. It can be relieving not to stress and perseverate on them. Going through life without pain is unrealistic; pain is inevitable. Revising your relationship with pain can be life changing.
When it comes to pain science, the biggest misconceptions are that people think it’s something we choose to do or something that gets added onto treatment. Pain science tells us that all of our interactions, environments, statements we make, and prior beliefs play a role in our pain experience and treatment. For the people who choose to “practice with pain science,” we just acknowledge the prior statement to a higher degree. We try to be cognizant of all the fluctuating aspects that relate to a patient, client, or athlete’s experience.
TR: The biggest misconception I see about pain among the general public is the widespread belief that pain equals tissue damage. You tell a patient that they can feel pain, even severe pain, without any damage happening to their body, and 9 times out of 10 the look on their face is one of shock and disbelief. We need to raise as much awareness about this as we can. If more people understood this, it would dramatically reduce rates of pain catastrophising and fear avoidance behaviour. In turn, reducing these behaviours could actually reduce people’s pain!
The next biggest misconception I see among the general public is that the back is extra fragile and needs to be treated differently from other areas of the body. For example, suppose a person hurts their elbow playing sport. What do you think they do after hurting it? They bend and straighten their elbow all the time to test it out and see if it’s feeling better. On the other hand, suppose a person hurts their back. Bam – full Tin Man mode is activated! The back is robust; there needn’t be such a stark contrast in response between these two incidents.
The biggest misconception I see other practitioners have about pain science is the idea that pain scientists think “biomechanics doesn’t matter.” Anyone with a proper understanding of pain science will never be seen or heard saying such a thing. They promote that bio, psycho, and social factors all play a part in someone’s pain, and which one matters the most in any given situation depends on the person in front of you, not your own predetermined beliefs.