Navigating the Pain Trail – Concepts of Pain Physiology in Running Injuries

Stay the CourseA runner glides along trail in the high-desert country, enjoying the sights and sounds, the fresh air, and the compacted singletrack beneath his feet, when he suddenly feels a “THWACK” of impact on his ankle. “Ouch!” It stings, but he doesn’t break stride. Thinking it nothing but a stick, he finishes the run… only to find himself bitten by a venomous snake. He makes it to the hospital in time to avoid mortal results.

A year later, the same runner glides along the same high-desert trail, when he suddenly feels a “THWACK” of impact. This time, he collapses immediately, intense pain up and down his leg. He looks back.

It was a stick.

Why the difference in pain response? Shouldn’t have the snake bite created more pain than the stick?

Pain is an integral part of life: it protects you and alerts you to dangerous forces, usually before tissue injury. And, as we’ve discussed before, it’s an integral part of running: it makes you behave (and move) differently, avoiding danger.

Runners have a love-hate, yin-yang relationship with pain. Few sports involve such liberal doses of self-inflicted pain. Perhaps that’s why we have such a high injury rate: when things hurt, does that mean “do more” or “do less?”

As a physical therapist (as well as coach and runner), pain is my job. Yet it is distinctly not. As I tell patients, “It is not my job to relieve pain, because pain is too complicated!” Phantom limb pain is an excellent example of pain complexity. Instead, my job is two-fold:

For the former, when you solve those things, pain usually – but not always – subsides. The latter job is equally important. Being Pain Manager helps people interpret the signals they’re receiving from their bodies and their brains, and effectively navigate toward normal function.

The researchers and clinicians at the Neuro Orthopaedic Institute (NOI) have helped us Pain Managers considerably with their work in the physiology – and psychology – of pain. Their book, Explain Pain, is the gold standard in my profession for helping to sort through the complexity of pain, and how we – as runners and people – can effectively navigate the pain experience.

This is the first of a periodic treatment by Stay the Course on pain education, as it relates to running injuries. I will start by introducing some fundamental concepts that we now know to be true about the pain physiology and the pain experience.

Pain, Defined

According to the NOI group, the most accurate definition of pain is:

“…a multiple system output constructed…whenever the brain concludes that the body tissues are in danger and action is required…” (Moseley)

That said, pain is anything the brain perceives as a threat. No one will argue that an all-out track mile or the last ten miles of a hundred miler aren’t acutely painful experiences. But we do them anyway because, despite the intensity, they aren’t a threat to our safety. However, the mere stab of arch pain for someone with chronic foot pain will stop them in their tracks. Threat value is everything.

Concept: Pain is Information.

With pain so eloquently and thoroughly defined, here is what it is not:

No Pain, No Gain
If it Hurts, Don’t Do It

We’ve all heard these statements; the former from fellow runners (or coaches, or race spectators), the latter from our health care providers. But the truth is, pain is information, nothing more. What, exactly, that information is telling is critical. Often times, the information is “Quit doing that!” But other times – such as during a hard track interval, stretching a stiff muscle, or a soft tissue massage – it is saying, “Oooh! That hurts! I need more!” or “Thank you sir, may I have another?” But sometimes, pain is a gross over-reaction to normal tissue loading.

Therefore, the job of any medical professional is to be a skilled pain manager to help us decipher and interpret what our bodies – and brains – are telling us, and then to develop a plan to work through the pain.

Applied: Patellar tendon pain. Many runners develop patellar tendon pain, often as a result of braking in their running stride (e.g., landing in front of their center of mass) or by a deficiency of knee flexion during their running stride. When the patellar tendon becomes irritated, knee flexion is most painful.

For those who follow the “If it Hurts, Don’t Do It” Rule, their response might be even less knee flexion – with running and walking. This would only make the tissue more irritated, and symptoms worse. In this case, the symptom – the information – is saying, “I’m tight and I need to loosen!”

The best prescription for patellar tendonitis (besides gait analysis to reduce any braking forces) is to increase knee flexion and perhaps (gasp!) speed up. This runs counter to the “Don’t Do It” mindset that drives most people’s pain response.

Concept: Pain is a Brain Output Based on Sensory Inputs.

In November, I attended a two-day workshop on pain physiology, put on by the NOI Group. The instructor, Adriaan Louw – a prominent researcher on the subject – related the concept of pain as thus:

Information from all parts of the body is relayed continuously to the brain – like different “departments” in a large company. The various parts of the brain act as a “Board of Directors.” There are representatives from the muscles and joints, the intellect, the emotions, the immune and endocrine systems, and more. These Board of Directors pour over that information, and they – as a collective – decide what to pay attention to.

Based on the quality of the information – and the specific experience, beliefs and values of the board – they decide how to respond. Inconsequential information – like the shirt on your back – which you felt when you put it on in the morning – no longer registers. But the dull ache of a long run, or the sharp stab of your foot arch on a stone – garners more attention. Information that the board determines is threatening must be acted upon. Based on the information – and qualities of the board – it takes action to protect you.

This action could take any forms:

–        The muscle system might increase tension to protect (as we discussed in the Achilles column),

–        The endocrine system can secrete adrenaline and cortisol (stress) hormone to protect against the threat,

–        The central nervous system might secrete inflammatory chemicals to “heal the tissue,” and

–        The intellect could send the message to “Stop Running!”

In most cases, this system is highly-effective in protecting us from threats to our system. However, the response to the threat is only as good as:

  • The information coming in: which is relayed by sensory peripheral nerves, and modulated by interneurons (“bouncer” nerves) in the spinal cord – and these nerves are sensitive to many different factors and subject to manipulation.
  • The Board of Directors: how effective it is at accurately interpreting the information and responding rationally, as well as the other demands that it is dealing with at that moment (work, family, life stresses, other illnesses, previous physical or psychological trauma).

Heavy stuff? Perhaps, but incredibly important stuff to consider when navigating pain. Because, what if the information absorbed from the peripheral nerve is over-blown or inaccurate? What if other factors beyond tissue irritation are impacting the Board of Directors and how it responds to those sensations?

Applied: The Stick vs. The Snake. The difference between the trail runner who finished the first run yet immediately collapsed in the second run was the brain. Sticks are not threats. Snakes are. Therefore, snake bites hurt, and sticks do not. The brain incorrectly interpreted the snake bite; thus, when a similar sensation came along, it over-reacted in order to protect.

Sharp joint pain, very often random impulses from nerves, or microscopic tissue releases, are often perceived as threats; chronic, dull joint ache – the cardinal sign of developing osteoarthritis – is often not. This is the challenge of overcoming pain, especially in a sport where pain is an accepted part of the experience.

Concept: Severity of pain correlates poorly to actual tissue damage. If you accept the concept that pain is an interpretation of information – from the peripheral nerves, by the Board of Directors – then you might accept that what we perceive as pain might not accurately depict actual tissue damage.

However, if that information is deemed to be threatening, it will hurt. Period. And the more important running is to our lives, the higher the perceived threat. The higher the threat, the more the Board of Directors will do to mobilize against that threat – more pain, more inflammation, more tensing and protecting.

There’s the rub.

In Part II, we will analyze this concept further, addressing both the physiology and the psychology behind pain versus tissue damage. Until then, a…

Call for Comments

However, rather than simply relating specific injury tales, I encourage commenters to examine their injury experiences under the microscope of these concepts:

–        What are your experiences with “Sticks versus Snakes”? Severe pain that was actually nothing serious, or severe injury that – at the time – registered very little pain.

–        How have you struggled with – or triumphed over – the erroneous Pain Rules: “No Pain, No Gain” versus “If it Hurts, Don’t Do it?”

–        What have you noticed about how your “Board of Directors” behaves with pain information? What about Running Pain versus Non-Running Pain?

 

Bibliography: Explain Pain, Butler & Moseley. Orthopedic Physical Therapy Products; 1st Ed. ( 2003)

Joe Uhan

is a physical therapist, coach, and ultrarunner in Eugene, Oregon. He is a Minnesota native and has been a competitive runner for over 20 years. He has a Master's Degree in Kinesiology, a Doctorate in Physical Therapy, and is a USATF Level II Certified Coach. Joe ran his first ultra at Autumn Leaves 50 Mile in October 2010, was 4th place at the 2015 USATF 100K Trail Championships (and 3rd in 2012), second at the 2014 Waldo 100K, and finished M9 at the 2012 Western States 100. Joe owns and operates Uhan Performance Physiotherapy in Eugene, Oregon, and offers online coaching and running analysis at uhanperformance.com.

There are 27 comments

  1. pdc

    I once ran around with a broken toe for 6 months with only a little pain. I don't even know how it happened…there was no material event disclosure from the board of directors!

    1. OOJ

      PDC-

      Your "Board of Directors" is very calm – a nice commodity in ultra racing.

      This is a good example, of many, of the interpretive variation of pain vs tissue damage. Throughout the "pain physiology/psychology world" there are "astonishing pain tales".

      This is a good example: http://abcnews.go.com/blogs/health/2012/01/21/x-r

      Very little pain, other than "headaches and nausea". There is a similar story of a man who had a nail embedded brain for FOUR YEARS without symptoms…

  2. Phil Jeremy

    During a 60k race, I was 6 hours in -(I'm slow) and at the top of a very steep 2000 feet climb as I started down the other side I got hit with massive knee pain in one leg, which I'd never experienced before. It felt like game over but as I was in the middle of nowhere I gingerly made my way down the mountain. Every step was painful but I 'felt' if I could just find a few K's of flat track it might ease.Your 'No pain No Gain' point comes to mind because eventually it did ease, just by running and 2 hours later I finished the race.

    I still don't know what it was and have never had it since! If I'd been near an aid station maybe I would have stopped. Great article Joe; as understanding when pain is serious and when not is always difficult especially in the middle of a race.

  3. anonymous

    I think it depends a lot on your actual motivation. In case of injury, I am willing to suffer and take huge risks in big races, but cut my run short in training for much less severe issues. Last year I landed my right foot on a little rock when not expecting it and suffered a stress fracture. It was at Leadville, right before the Tree Line, close to mile ~27. It hurt like hell and I pretty much knew right away what happened. I basically could not run flats. But I still could climb well, and decent fast on heels. I cried a few times due to pain and because of dissapointing my friends who were waiting for me at Twin Lakes (one even came all the way from Europe). I just thought I'll keep moving as long as I can. Around mile 70 the foot got so swollen it stopped hurting. So I finished. It was my first 100M.

  4. Josie P

    Anybody else get phantom pain on race da?y – you know, you go out every day of the week and feel nothing, as soon as it's race day you're full of random (but very real) pain in various body parts for the first few miles until you forget about it… odd

    1. Vlad

      Interesting … I thought it's only me. I am OK most of the year, then comes the race day and something always starts hurting pretty bad … the knee, Achilles, or ankles … so I toe the start line thinking it's really not worth running and that I'll have to drop by the first aid station … despair pure … then after mile or two all the pain is gone and I usually do much better than originally anticipated.

    2. Charlie M.

      Opposite for me. Always feeling pain on daily training runs, thinking I won't get to the start line, and then I show up and gun the engine and the pain goes away…until the first training run on the following Monday…

      1. Charlie M.

        I also think that once you've been injured in a way that results in major fibrous (scar) tissue replacing formerly elastic tissue, you HAVE to accept that the Board of Directors will be in control, and will view many benign signals as threatening. For me, every time I try to increase range of motion in my left ankle, the response is that familiar constriction of fibrous tissue, accompanied by a pain signal. It makes every run laborious and frustrating, but I guess the alternative is continual re-spraining of the ankle. It is only when I race short distances (5K) that I don't "think" about the pain, probably because all thoughts/energy are directed to the task of running all out. At race pace (sub 6min mile), there is no "guarding" of the ankle, it either survives or it doesn't. But on a training run (8 or 9 min miles, etc.), the mind swirls with questions (should I get surgery?, how far is my range of motion?, why doesn't it feel right?, etc.). Very interesting that the Board of Directors is silent during the all-out effort, but won't stop talking at jogging pace.

  5. Michael

    When pain starts kicking in during long runs, or I feel like walking on ordinarily easy terrain, I stop for a split second and recalibrate. I ask myself "are you really out of breath? Do your legs really hurt? Then why aren't you running?". I then feel a bit foolish and start running again completely pain free. It seems my Board of Directors aren't the smartest.

  6. sharon

    Wow! This was very interesting, and very well explained.

    I badly and painfully tore a lower hamstring on my left leg 2.5 years ago. It took over 2 years to get over the injury, probably because I started training again as soon as I could even though I could not straighten out my leg when I ran, or climb stairs with out relying on the guardrail. (I DID have 2 physical therapists say that I could start up again.)

    The last 3-4 months I have still been getting regular massages from my currant physical therapist, often complaining of pain in my left leg when I train, extreme cramping during races, and that sort of thing. He insists that I am MUCH tighter on my right side, an injury waiting to happen, and that while the left leg is weaker, the muscles are nice and loose and in fine form. Once when working on my calves where the achilles tendons attach to the muscles he commented that most people whom are this tight here complain of achilles pain. But I have never ever felt achilles pain. He answered that it could be that I have never had an achilles injury because I have never had an achilles injury. Now I understand this better.

    I am hoping now that my "board of directors" after reading your article can again ignore the pain on my left side.

  7. OOJ

    Phil-

    Good comment! This is a good example of the importance of "being relaxed and normal"!

    Often, with repetitive stress, a joint can become "unhappy" (e.g. slight flexed knee gait repetitive on an uphill), and a bit of joint asymmetry (bone gliding) can create significant pain.

    But simply getting back to a "normal stride" (e.g. "a few K's of flat") was enough to get the joint moving and feeling better. Full, gentle motion is the #1 most important element to joint happiness and pain relief…even if it hurts a lot, initially!

  8. OOJ

    Anon-

    Motivation does determine "threat". An injury mid-race can be threatening…but if you're "into it" and know you cannot stop, you "put it away" and run, as you did.

    However, if you're 2-3 months out and you have pain, your motivation (and "threat value") can change significantly: creating fear of movement, high anxiety, and greater pain than what might've been if there wasn't that "anticipation". More on that concept in the next post.

  9. OOJ

    Charlie-

    The difference between the 5K and the longer runs might also be THREAT: if you've had a history of being 100% OK during flat 5Ks, there is no threat (think: running in the city). But on the trail or long run – where you've been hurt before – the brain remembers (think: snake-bitten trail runner back at the scene of the bite).

    Those "mind questions" represent what are called, "Thought Viruses" – negative thoughts about pain that, ultimately, can create nervous system hyper-sensitivity and amplify any input (temperature, pressure, sharp/dull sensations) as "THREAT"/"PAIN"…

    1. Charlie M.

      Yeah, that's definitely part of the equation…but I think I would go all out in a trail 5K too…it's something about a short distance where the extreme effort and decision to "go for it" completely overrides the Threat perception mechanism. In a longer race, where I have to constantly assess and re-assess and hold back and monitor, etc., the Governor and the Board just completely take over and I feel pain that I didn't feel in the trail 5K the week prior. Bascially jogging hurts and running hard doesn't. I know, I know, I should just gun the motor all the time…but then my mind remembers previous bonks, etc. Guess I'll just do the 5K's :)

  10. OOJ

    Good observation.

    AJW has written at least once about the notion of "brain training" in running, and the idea of the "Central Governor" theory – where the brain (e.g. The Board) decides how fast you can run, based on the calculations of terrain, temperature, "body feel", and perceptions of fitness/strength.

    The Board can be negotiated with, as you've noted. Training to be "uncomfortable" is important in this, as well.

    http://en.wikipedia.org/wiki/Central_governor

  11. OOJ

    Sharon-

    Thanks for sharing.

    This brings up the important point of "defusing the threat". A major paradox with injured runners returning to running is this:

    We desperately want to run, but

    We are extremely afraid to run, because we might re-injure ourselves

    When we want to run, but fear re-injury, it's like driving down the road with a foot on the gas, and a foot on the brake.

    It's also like this: http://www.youtube.com/watch?v=k9Nh0Fvoe9k

    You either jump, or you don't.

    The challenge is to develop a progression where the amount and type of running is NOT a threat. As such, I will very often prescribe shallow water [REAL] running for folks: real running, 50% weight-bearing, and NON-threatening. Do a bunch of that, the brain relaxes, run mechanics are normal…then go to land…

    1. sharon

      I have gotten good at jumping, but I have yet to land on the next building.

      I get honest to goodness cramps after 50 km which are VERY painful. I think I am re-injured, but one light massage and I am 100% again. I need a way to relax the muscles while I run. Finding a progression which is not a threat sounds right. Knowing I can trust my PT when he says that my leg is fine, is a good step forward.

      Thanks again for the article.

  12. ScottD

    Great stuff, Joe!

    I've found that my initial pain reaction tends to be more exaggerated than it should be. I twist an ankle on a training run, and the first surge of pain convinces me it's broken, but then I wait a bit and the second wave of information tends to be more accurate (and usually significantly less). My Board of Directors is a bit hypersensitive, I think.

    The most painful week for me is the taper. The Board comes up with all kinds of weird aches and pains that I've never felt before, and they all mysteriously disappear on race day. Weird.

  13. Scottay

    Looking back now, I think I ran for the better part of a year developing and injury I never felt. For months I ran with very little 'pain', rather slight discomfort in my right hip. The hip ached only slightly post runs. At the end of my last 50 miler, I decided it was time to take a break. After 4 weeks off, I was still feeling discomfort in my hip. It was then decided to seek support form a massage therapist, and then acupuncturist. I've spent a good amount of time with both and have discovered just how much pain I had been seemingly "suppressing". I never went to a sports doctor, or had an MRI, but I do know now that my sartorius muscle HURTS, along with a whole host of other compensating neighboring muscles). The pain I felt in my hip was a result of my increasingly failing running form, and compensation for the injury occurring just above my right knee. I haven't run more than a few miles at a time in the last 3+ months. While I am feeling "fine" I am trying to be patient. I am amazed at how calm my board of directors are. Maybe too calm. I wouldn't call it 'no pain, no gain'. I honestly never felt what my brain would interpret as real 'pain'. The process I've been thru has been amazing. Eye opening, and I feel like I am relearning how to sense my body for the first time. Love your posts! Can't wait for part II.

  14. Anne

    I actually had a "stick vs snake" experience a few years ago. It was a January day when snakes are supposed to be in hibernation but there were a few days of warm weather after a big storm. The trails were littered with tree debris (twigs and branches). As I was running on the trail, I felt the twack on the back of my ankle and then it started to sting. Since I was running in a tight group, I did not stop and figured it must have been a twig. Just after that incident, I had a branch hit my calf and it cut through the skin and had a different feeling than the previous sharp sting. I stopped but did not see anything on my ankle where the first hit occurred. The next day, I saw two large, identical, bright red holes on the back of my ankle and figured it must have been from a rattlesnake that was underneath the debris that I ran over. I have had numerous close calls with rattlesnakes so every time I feel a hit to the back of my leg or feel some sort of sharp pain or sting, I always stop and check it out. It is an experience that is always fresh in my mind when I run trails especially in warm weather. Do not believe it when people say rattlesnakes will only strike when intentionally agitated or proked. They can strike sight unseen.

  15. Greg Veltkamp

    As I drove to the start of the Resurrection Pass 50 last year, I was listening to a Radiolab podcast called "Loops". The last piece on the podcast was an interview with Melanie Thernstrom, writer of "The Pain Chronicles". She experiences chronic pain due, in part, to an over use injury. She participated in a study focusing on the negative connotation associated with pain. By viewing her pain experiences (while dialed into an MRI brain activity viewing machine) in a positive manner, she was able to break the negative loop, which had been feeding itself and causing her pain to propagate. She viewed herself as a Saint or a martyr whose faith would protect her from the pain.

    Late in the race, I tried it. My legs cramps and nausea were simply side effects of my absolute devotion to my pursuit. My faith in trail and ultra running would protect me from the ill effects of these bothers and ultimately assist me in transcendence. Why not run faster? Surely, my discomfort and self-induced persecution were only necessary accoutrements on the path to righteousness! Although not having run a single speed workout all summer, I ran miles 20 – 30 at roughly 6 minute pace. No pain at all – I was in control of my destiny! And it all came crashing down. I managed to work through the unbearable leg cramps and hold on for a respectable finish and in doing so, taught myself a valuable lesson. Have fun with your pain. Yes, the Board of Directors needs to pay attention and act when necessary, but when its manageable, play around with it. Imagine a horde of miniscule gnomes inside your body, rushing to the sight of the pain to work furiously at correcting the problem and keeping the machine (you) in the game. Having a positive outlook while experiencing pain is absolutely helpful and necessary while enjoying our long sojourns through the woods.

    1. OOJ

      Greg-

      AWESOME post – one of the best "pain stories", and best examples of logical rationalization of pain I've ever read. Thanks so much for sharing!

      This same mindset is incredibly important for injury pain, as well: get the facts, rationalize, *know you're safe*, then make your symptoms into something positive (or at least something you're "OK" with).

      Way to go, thanks again!

  16. Damian D.

    Oh man, the pain definitely affects your training and actual race day. From an old soccer injury, I have a weaker right ankle that I have to constantly stretch and strengthen. From this I have learned that you have to let pain guide you. As crazy as it sounds you have to let pain "talk to you" and take it as signals for what needs to be fixed. The key is to always push a little bit at a time and challenge the pain.

    1. OOJ

      Good insights, Damian, thank you. For an issue like that, it IS important to thoroughly address "Job #1" of the sports med professional (e.g. "M-n-M"). Once that is covered, accept the information coming your way. BUT, remember to consider that the information coming from the ankle to the board might not be entirely accurate for "true tissue irritation" in a chronic pain situation…. More on that next time…

  17. Rip Vanracer

    I fell 10 miles into a planned 15 mile trail run and separated my shoulder. Since it didn't affect my legs, I ran the other 5 miles even though it happened near my car and I should have quit the run. I couldn't lift my arm over my head for two months but I could run if I held onto my shirt!

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