Centralisation, Part 1: Mechanical pain, mechanical diagnosis and the Wrasse bite

(Part 2: Pain centralisation:- another stab at explaining a clinical observation – will be the next blog.)

The overall plea comes down to this… Could we please substitute the term ‘Mechanical pain’ with the term ‘mechanically patterned pain’?  This article explains what I think both are, what they mean, and why we should change.

This is rather long, sorry, suggest you go for a run first then grab a beer and a tranquilizer…


Two days ago I cut my finger.  I was fishing and caught a sizeable Ballan Wrasse, about 3 lbs, the nearest thing to a pretty reef fish that the UK has, but no good for eating.  They’re good fun to catch but hard to get off the hook because they’ve very impressive sharp teeth and small hard skinned mouths. The end result is that after a tussle with the fish and a deeply embedded hook, it bit me and I jerked my finger out of its mouth which made the skin wound even worse.

My Wrasse wound helps this discussion, I’m sure, but not quite yet.

Mechanical pain – implies mechanical fault – implies it needs mechanics to fix… (to me)…

I have to say that the term ‘mechanical pain’ and accompanying phrases like ‘mechanical pain requires mechanical therapy…’ I’ve always felt uncomfortable with and feel need a bit of an airing.  One implication is that a mechanical fault needs mechanical forces to correct/help.  Clearly, if you break your leg there’s a mechanical fault and mechanical remedies like screws, plates and plaster are mighty helpful in the early management.  I fear that the term as applied in musculoskeletal pain presentations, particularly related to the disc in low back and neck pain, promotes the myth of ‘putting something back’ or ‘reducing a derangement’ in some way, and in so doing side steps the wonderful chemical-physiological-neurological-biological healing and pain process going on, which…. even for the skin, TAKES TIME, and moreover for the disc, is interminable and ultimately next to useless.

An aside on disc metabolism. 

For a biologist the disc is moribund – and therefore nearly/virtually dead in terms of response to injury… It’s metabolically incredibly slow:– biological turn-over rates of disc material are measured in years/life times.  If you’ve the time and interest, please read my chapter/discussion on this that’s on this blog at this link: https://giffordsachesandpains.files.wordpress.com/2013/06/06-chapter-ju.pdf

Particularly the section in the chapter that reads: But why does the disc bother to hurt?

A big point is that a damaged disc does attempt to repair itself but for the most part degenerates rather than aspiring back to a full and normal hydrostatic state of well-being.  It’s a bodge job and it doesn’t matter whether you rest or move, the outcome is much the same, your disc never gets back to how it was; dream on.  Putting a disc ‘back’ is also a myth, but there’s now plenty of evidence that any extruded disc material gets gradually ingested, nibbled away at and removed by the immune system. Clever, but you have to wait, it takes many months.   An important point for us all and our patients is that even though a disc may degenerate or be degenerate, it is still a good functioning structure and very strong.  Live on! (Changed joint mechanics is an interesting story…)

The big deal arises from the question… What’s going on when the pain goes rapidly, the range improves and the pain centralises…and very soon the patient’s pain has gone?  … and the answer is that the disc can’t have healed, recovered, reduced its internal derangement in a matter of a minute or two.. or even over the next few hours, days, weeks or months…

(Don’t get mad with me…hang in there.., yes the pain problem does improve rapidly but we need a better explanation than the anatomical and ‘reducing’- something ones.  That fluid moves in and out with movement, like all good collagenous tissues, is a given).

Some illustrations of my problems with the term ‘mechanical pain’ and the underlying notion of what ‘mechanical therapy’ does:

This illustration is typical of what I think needs challenging…

Note this quote is from (http://shp.missouri.edu/vhct/case1699/3LBPsyndromes.htm) that I found at the top of a 2 minute Google search using the term ‘mechanical therapy’ ….(this is the website from the University of Missouri-Columbia School of Health Professions… teaching new physical therapists what to think and believe..).  What this website is saying, is very familiar…and is what a great number of therapists the world over believe I feel…  (‘Oh no they don’t’… ‘Oh yes they do’… The scientific rigor here is exemplary.)… Here we go…

‘Symptoms tend to centralize and eventually diminish as the displaced disk material is relocated and the deformity of surrounding tissues is reduced……’

The rest of the material on the page is along a similar vein.

Thoughts….and discussion…The argument that ‘therapy works’ – that the pain goes with mechanical therapy (meaning with exercise, movement, manual therapy etc) doesn’t prove that what you are doing restores the mechanics back to normal at all. It just proves that movement helps the pain at that instant, or, if the patient gets better and better by repeating a movement over many days or a week or two, that the movement has helped to ‘desensitise’ or turn the dimmer switch down on the pain representation in the nervous system.  This includes the terminal zones of sensory nerve fibres in the tissues too.  It’s as if the nervous system ‘decides’ that the damaged tissue is not a real threat to homeostasis and there are better things to be getting on with… ‘Hey, disc, I know you’re all fissured and cruddy, man-up… I’ve got a life to get on with… you’ll cope…Bye…’  The sun goes down and the slightly embarrassed and rather meagre little sensitised nociceptor population turns over, pulls the covers up and goes blissfully back to sleep again. Amen.  Or, they stay awake but the nervous system decides to blank them and their central nervous system representation’s access to consciousness… ‘You know, I thought it was awful, but now that therapist has shown me how good it is to move again, I’ve changed my outlook…’

What I’ve just said amounts to this statement….  ‘That just because a pain rapidly improves with movement/mechanics/manual therapy – doesn’t mean that it’s reducing or fixing something in a very short space of time, that’s just not possible ….’  In fact some forces used may not even be doing the tissues any good even though the pain may get better.

Another example for consideration….

Let’s have one more example from what I’d call, (with no apologies until they can prove me wrong), …. a pseudo-scientific professional …..This is to get the balance,…..we love criticism of our competitors but we can’t take self criticism..I’m the same…but knowing you’re like this helps to quell the emotion a bit… (Please find time to read Stuart Sutherland’s brilliant book: ‘Irrationality’)

I’ll get to the ‘pseudo-scientific- profession’ example in a moment; it needs a little introduction ….ahem….

Mechanical and manual therapy in physiotherapy has forceful high-velocity ‘Grade V’ thrust techniques at one end of the spectrum and gentle Grade 1 mobilisations at the other……. Grade V’s were what we used to call ‘wopping the joint’ back in Adelaide in 1985 – hence our tee-shirts with ‘Wop 85’ on and a cartoon of the exact opposite, the Maitland grade 1 mobilisation, – ‘bending the fly’s knees’, printed under the ‘Wop’ statement.   For those who haven’t come across the bending the fly’s-knees analogy, it means that you place your thumb tips on the back of an obliging fly’s thorax which is obligingly standing on the spinous process you want to mobilise.  You then oscillate up and down just enough to bend its knees….a virtual technique pretty close to hands-right-off healing energy or is it energy healing?  It’s a small point, but our profession still does pseudo-science too….

Anyway, I am reminded of witnessing a McTimony Chiropractor doing a demonstration at an osteopath conference where I was giving a talk on neurodynamics, a long time ago…. Nothing’s changes here either…  Check out this website – http://www.mctimoneychiropractic.org/  and note this from the site…:

Chiropractic treatment is simply a method of adjusting the bones of your body to improve skeletal alignment. In doing so, it helps your nervous system work more efficiently, relieves pain and discomfort, and increases mobility.’

… and this….

‘Your McTimoney Chiropractor is trained to correct misalignments using quick, gentle and accurate adjustments which ensure you experience maximum comfort.’

The McTimoney chiropractic that I witnessed that day was with rather flamboyant and dramatic hands-on followed by a very quick ‘swipe’ of the hands across and away from the flesh… leaving the ‘flab’ oscillating for a moment or two…and probably a nano-film of skin removed…  and then there were lots of verbal positives about better movement, released and realigned segments… (the guy did feeble passive intervertebral movement (PIVM) testing and revealed how good it all was after the ‘flab wobbling’).  It was certainly on a par with a Maitland style: do a PIVM test, then do a ‘Grade 1’ mobilisation, then re-test the PIVM and praise the Lord.   As far as the result on the tissues and joint under the thumbs/hands are concerned… no direct effect whatsoever I’ll propose.

That processing could have altered I am definitely not denying, nor that good money is exchanged for a very brief encounter, or that it is classic pseudo-science because of the claims about what it does and how it works.

Now, if the patient gets up and moves a whole lot better… it must have influenced the joints’ mechanics??… No, see it as processing change and change in reflex/feeling/fear/muscle tone whatever and a new willingness to move… Is that subconsciously possible?  Very!  (See the continued discussion that’s at the end of the last blog about sex and leg length…There, I look at cranio v reflexology for back pain.. and hey, both reportedly fix the same pain as we found out by a good and surprisingly honest interview with the pain afterwards.)

The big issue here is the McTimoney notion of ‘realignment’, of change in mechanics from the hands on encounter….Come on!  At least Geoff Maitland never climbed over his Brick Wall and said that a Grade I was altering collagen… he just stood by the result and accepted something must have happened, or, binned the technique for that patient if it didn’t produce some change.

One problem the term ‘mechanical pain’ has to face is that without exception, all pains are the result of a neurobiological process, – they’re all about impulses, bio-electricity, electro-chemicals, consciousness and vast levels of complexity in representational areas and homeostatic monitoring modules of the brain, far from the injured tissues and the location of the pain.  Granted, mechanical forces start injury pains off… like the Wrasse’s teeth gouging and penetrating through my skin.  Mechanical pain exists at the moment of the physical injury.  Mechanics does the physical damage and leaves a physiological and anatomical mess for the body’s healing system to clear up and mend as fast as it can.  I think all would agree that no amount of movement at the time, or just afterwards can restore the anatomy quickly back to normal again…you just add to the injury surely?  Try sutures perhaps?  Is that the best modern medicine can do for a wound?  Virtually, yes!!

That movement and graded mechanical forces – usually produced by getting normal functional movements going again in a graded way, – helps healing tissues to form a healthy scar repair is not denied, but the healing biology requires TIME and patience and mechanical dips in and out.. And that is a bit of a problem in this age requiring the ‘instant fix’.  That is where ‘conning’ or ‘tricking’ the nervous system comes in and why we could all try and invent a new pain treatment.  See what you can come up with and… get away with too…  I’ve already written about ‘tricking pain’ here: –


Instant changes in pain with treatment may be largely irrelevant to the overall healing process, other than making it feel transiently better (a psychologically positive step of course).  Or maybe it’s the same?  Or maybe you made it worse?  Did you wake up grumpy and couldn’t quite get the right atmosphere with the patient? … The patient didn’t trust you, thinks your weird…that creepy shudder effect perhaps…?  (Facetious Headline.. ‘Read all about it….Mechanical pain made worse by mechanical therapy because the therapist made the patient feel creepy…Therapist denies everything…’)

On the other hand, if you can do something to make the pain better, you can use the good result to reassure the patient that their system is capable of winding down and shutting up… all you have to do is help them to find a way of doing it…. That’s one good thing about a system that uses movement to change pain, so long as it doesn’t create fear of structure, as I see it, we’re good.

Something more positive now….Isn’t it great that sometimes sharp pain makes you actually want to move it and massage it a bit.   Writers and books about pain that tell you pain means stop, rest and avoid so as to let the injured tissues heal just haven’t listened to the reality of pain at all… don’t you just love to move your neck into that sharp pain occasionally to see if it’ll move a bit further…?  Don’t you just love to pick that scab off the wound…?  Clever pain!  ‘Sometimes sharp pain makes you want to try it and move it slowly… Aching pain and stiffness makes you want to get up and move… From time to time the tissues need a bit of movement and good adaptive pain gets you to do just that.

I’m pleading for those who think ‘mechanical’ in the clinic  to try and understand and embrace processing changes far more… and also think about the purpose behind movement making such dramatic and quick changes even though the movement could be making the tissue situation worse.  This question is an evolutionary ‘why’ question, ‘why’ would that sort of response have evolved?  I’ll answer that shortly.

Back to my Wrasse bite..Any piercing of the skin is an anatomical emergency, a sure threat to homeostasis and as a result we’ve evolved the most fantastically complicated response to shore it up, make it aseptic and physically safe.  The said process is chemical, immune, neuro-endocrine (C fibres and sympathetic efferents spew out neuropeptides), electrical and sedately physical too as the whole area re-grows to bridge the gap and draw the tissue together again.

The threat of the original ‘cut’ through the skin is almost instantly signalled by mechanical forces being transposed into electrical impulses at the ends of sensory fibres… all of them, that’s the Aβ, Aδ and C… some of which are also more than likely to have suffered damage themselves. (You can’t cut through the skin without cutting through sensory fibre axons and their nerve fibre terminal branches)

So, mechanical forces produce the cut and its pretty ‘ow’ straight away, (well the excitement of the fish held things at bay for a moment or two).  I knew I’d been cut though, I felt that, but it didn’t bother me… Then once I’d dealt with the fish and returned it, the cut was a little sore and there was blood all over the place for about 15 minutes.  Instinctive licking adds saliva – a natural antiseptic and clotting agent… and in the end I tie my handkerchief round it so I can get on with the fishing.  Didn’t bother me for the rest of the day.

Two versions of mechanical pain that I’m comfortable with:

1. Bend your finger back and keep going.  At some point it gets nasty and you usually want to stop because it’s smartly telling you that you’re approaching the tissues limits.  Or put your first finger in a woodworkers vice and start tightening it up.  If you’re awake and concentrating, the greater the force generally, the greater the pain.  Smart, evolution of a nasty sensation puts a stop to potentially damaging forces causing injury.  That clear relationship between force and pain is how we’d all love pain to behave in every problem and every patient… but it doesn’t.

2. Have a Wrasse bite through your skin… it’s the instant pain you get that relates to mechanical forces and then…anatomical damage…. etc….

Both 1 and 2 produce pain because of transduction of mechanical forces into impulses and those impulses reach the brain where pain production is an option for the brain to decide on.  So, well it was mechanical, but it instantly became….. a whole lot more complicated… very quickly… so is it mechanical pain then… ah? …..Up to you…., call it whatever’s easiest, so long as you don’t forget the processing in the brain part.

All pains involve the brain and ‘you’ the sufferer. It’s practically instant from mechanics to electrical to cognitive-emotional-behavioural… You imagine how you’d feel being bitten by a Wrasse…or having your finger in the vice? Right.., if your brain is switched on there’s psychology in every pain every time in every place…. The very word associated with pain is ‘aversive’ – and demands… ‘ alter your behaviour quick!’ … ‘avert’ means to back off, turn away…

A plea- don’t listen to these Cartesian dinosaurs who harp on about real pain equates to mechanical pain that needs mechanical treatment and that the other type of pain is psychosocial…  or ‘central mechanisms’ or even ‘not real pain’…. There was a pain revolution in physiotherapy from about 1995 to 2005 or so… remember?.. Or was it all a waste of time?  Some of us are starting to wonder!

Now, On-off pain with movement….in early acute stage and early healing…Back to my cut finger which is now, two days later, gaping, weepy, a bit crusty and…. I nearly said sore… But in actual fact, when I keep it dead still, with the finger in a position that doesn’t stretch the skin there is not one jot of pain, even though it’s clearly in the inflammatory stage of healing.  If I move it, bang, pain on… move it back, pain off, ….pain on…. pain off….pain on… repeated movement… on, off, on and off… and hey, the pain’s getting gradually less…. and I’m going further…. easy, less stiff too and wow…mechanics cures mechanical pain….!  Oh, damn, it’s bleeding again… never mind I’m moving it and its getting better… Same thing if you want to massage it… pain goes but it weeps and bleeds more… That drains the toxins away, clever see…there’s always a ‘smart-ass’ reason for everything… Oh! ah?.. mmmm, Yes, … and that’s why we like to move and massage a swollen joint or anything that’s swelling is it?  Could be….  Think like this: The swelling dilutes the inflammatory soup a bit, so swelling is an adaptive ploy, plus there are all the toxic breakdown products, they get diluted in the swelling too… Dilution by swelling reduces the ‘bad’ side effects of these products… But then the swelling makes it stiff and achy and so it makes us massage and move it to free it and in so doing…clear much of the fluid away ….  Ah, there’s a hand up in the audience… ‘So the RICE Rest/Ice/Compression/Elevation thing goes a bit against evolution then?’ … ‘I think so… swelling going up and down in the aftermath of early injury is a good thing… do it… don’t compress it for too long.. be guided by what it wants you to do, not what someone tells you, you should do’… ‘Ah! Right?’

Another question from the audience… ‘So getting the patient to stay in one posture for long periods, like for example maintaining the lordosis goes against the grain with evolution too…?’…..  ‘Good, you’re getting the idea.’

So early movement and pain on/off can be argued either way… may help, may make it worse… But the truth is that using mechanics (ie. Movement/forces of some kind) can make the pain better, even though it might be putting the healing and damaged area back a day or two….. so… ‘ Doc you advised I keep moving it, 10 every hour, or more often if it starts to bother me?…Yeah?  OK…. it keeps bleeding… I think your advice was nuts…

Frequently asked questions from the make-believe forum…

‘So does doing early movement matter if the injury’s in the disc?’  Answer… If it is just a disc, the answer has to be no, because what difference to the end result would it make anyway, it shouldn’t matter.  Wise action is to progress with graded build up of forces though.

Could movement be squeezing more material out of the disc and around nerves…?’  Well maybe it could, but Mike Adams the disc expert said that once an extrusion has occurred more material is unlikely to come out… Early end range movement and consideration for the nervous system is something important that needs considering.

‘Could the movement be making a bulging disc squash a nerve… and injure it without immediate or even later symptoms….?’ Well, yes it could and that’s something that needs considering….Graded increase in movement and range is the wise way forward.. On the other hand, it could just happen anyway, it’s hard to know!  Hunter gatherer’s never had a clue what was going on … and may have survived fine with a foot drop and a friend who helped them for a while..

The ‘Action more important than healing view’…this is the answer to the evolutionary ‘why’ question from earlier…

Why would the pain get less and less in the face of screwing-up the carefully crafted early healing process and putting it back a day or so?  All those fibrin strands and all those little platelets snugging in there, going, ‘What the bloody hell does he think he’s doing…that’s such a nuts thing to do?’

Think hunter-gatherer and you realise that using the injured finger is often essential and that hey, the process can start again anyway, what you don’t want is horrid pain when you really have to use your finger… And, imagine I’m out there fishing again just about to land this 8lb Pollock, no way am I going to let that beauty get away, grab it with both hands, the fish is bleeding, I’m bleeding again, but hey no problems, I’m not a haemophiliac, it’ll mend later.  Sorted.

Here’s another, my Philippa dropped a Calor Gas cylinder on the top of her foot recently.  It hurt enough at the time to curse and blame someone else.  For the rest of the day it eased right up, but it hurt like hell that night… what’s the point of that kind of pain?… That’s an evolutionary ‘why’ question that’s hard to think of an good answer for…but hang on a minute….  Injuring your foot is a bad thing to do because if you can’t walk you’re going to find it hard to run away, to hunt and gather…It seems that there are some parts of your body that are more painful when merely knocked or banged than others and one wonders why.. Now anytime you hurt your foot evolution has made it that it hurts like hell so that you learn to be more careful next time…You need your feet and they’re a little vulnerable down there….  Think about stubbing your toe…hurts like hell,  Yet, the same force on the side of your thigh, arm, trunk… not a problem, unlikely to damage either…  Same argument for banging your head… really bloody hurts compared to similar forces on other areas of your body….. evolution says… look after your noggin you nog..look after your feet too… and your eyes, they’re sensitive and important.  Nose?  Nah! (If you’re a bloke!)

Last time now….‘Mechanically patterned’ pain is no pain at rest, pain only with movement and no pain immediately after the movement.  So this pain from bending my cut finger was mechanically patterned, and shouldn’t be classed as mechanical pain with the connotation that it can only be fixed with mechanical forces.  Movement in the early stages of injury can be argued either way, but mostly we heal well even if it is mostly by scar formation which later may initiate degeneration, but, hey ho, the pain goes away and good function returns.  The evidence says rest longer than 3 days is detrimental for spinal pain.  Good rule.  Keep moving and if you don’t want to, maybe think about converting to becoming a tree, mind you, those windy days won’t be too pleasant.

On-off pain as time goes on….Now, I don’t want to make an argument for moving or not moving a musculoskeletal tissue just because a bit of neuro-chemistry and a brain is involved. I’ve spent my life trying to stop people resting and get moving and we know most tissues heal as we continue to function and that prolonged lack of movement is overall a bad thing.

The plea is to swap the term to ‘mechanically patterned pain’ and consideration of the state of the tissues based on other findings from the history.  For example, if my on-off pain in my finger was 2 weeks, 2 months or 2 years old and the pain subsided with movement it seems like a good ploy to do the movement to help desensitise it.  Note the thinking has shifted from mechanical fault fixing to ‘desensitising’ – using movement, or mechanics, to alter pain processing that’s stayed sensitive too long.  It’s maladaptive pain and sensitivity.   (I like to use the term Maladaptive pain processing in this context to mean pain out of proportion to the damage done).  ‘It’s time you shut up dear’.  In other words the tissue’s being a bit over-sensitive and there’s no point in having the amount of pain it’s having. Tell the brain too.

So give patients the de-sensitising message and a positive structural/anatomical/strong recovery one – or you’ll be stuck with the ‘it’s not fixed’ problem when they don’t improve… and the patient will end up with therapists like me who try to unravel their maladaptive pathological/anatomical/biomechanical beliefs…and then provide a much better and more hopeful perspective.

Too much early movement??  The battle of the neediest…Now, a bit of movement based pain modulation is always nice, especially at first….But it may be only up to a point.. I know, that if I keep on doing the movement to my cut finger right now, it’ll eventually get mighty sore, it’ll start to ache, I’ll end up being much more protective and it’s more than likely to stay sore for longer than it otherwise would have.  Short bursts of essential activity are fine, but eventually the tissue can win out in the continuous arms-race between the brain’s need for function and the tissue’s need for a bit of rest. (Remember, healing by scar formation of collagen takes months to a year or more…mechanically patterned pain that gets more and more sore needs consideration of this slow healing… and everyone being more patient with recovery time perhaps? Think of the time line for knee collateral ligament injuries for example)

Repeating movement of normal tissues….So repeated movement can be pain relieving and purposeful, but do too much and it often gets shitty.  This is even true of undamaged tissues.  Here’s a challenge…. do a repeated movement, say wrist extension to end range, make it fairly hard too… and I’d like you to set off to do maybe 200 reps., and see what happens… sort of thing a gymnast might do when practising their handstand routine say.  Count the number of handstands/reps to ‘sore’ and note if it leaves you sore for long afterwards.

Everyone varies, but there’s a good study in this for anyone wanting to do ‘normative studies’ – a passion of mine…  Don’t just do the wrist though, make sure you get normals to do all the spinal movements in all directions too… and find out the max, min and average ‘to-sore’ score.  It would be so useful to know in the clinic.. don’t you all agree??  Easy to do too and it’ll get you a masters.

Now, is it tissue tolerance or gating efficiency that you’re observing?  Get the observation done first and sort that out later… it’s probably a bit of both.  Don’t forget to measure pain tolerance of each individual before you start too… you know, put the forearm in ice cold water and see how long the subject can keep it in there for… remember us blokes can stay in longer if there’s a hot chick present while they’re doing it… Does that help us see that psychology is involved in pain with every pain, every time?

Research plea… Let’s stop trying to prove our techniques are better than placebo, they’re not… Let’s turn our attention to finding out more about normal responses and normal recovery history and timing… Recovery has been done quite well for frozen shoulder, poorly for sciatica and desperately needs doing for carpal tunnel syndrome, tennis elbow….. Achilles tendonitis, plantar fasciitis….  to name a few…

Now you’ve done those 200 handstands it’s time for the ‘Staying completely still’  test…. ….which is right at the other end of the spectrum.  I call it the ‘how-long-can-you-stay-still-for’ test.  Again it relates to mechanics in that it’s no movement and constant pressure, or constant stretch just about everywhere.   The ‘living/human-statue’ thing you see in street theatre… give them money and they usually move a little.. then, well, they look pretty dead again… staying completely still like this for long periods I’ve always viewed as an impressive form of torture. Being still is not conducive to tissue health or tissue life unless you’re a dandelion in the doldrums,  a well practiced human statue or a yogi who’s got nothing better to do than nothing with their brain.

While it’s mechanics that starts it off, it’s eventually what I call ‘botty-rot’ pain that results for any sitting still human-statue attempt-tee..  Tissues that don’t move don’t get any circulation…and soon get cranky.  Bend your fingers back and observe the tight skin in the palm of your hand. Note the colour, the white where there’s no blood and the blotchy bits where the blood is pooled and stuck.  Keep it there and keep staring.  No change in colour, no blood movement. All mechanical?  Sustained posture pain perhaps? The tissues like oxygen and nutrients fresh every few seconds and because they function like us, they need to run the sewer out regularly too.  Block these processes and the tissues start oozing inflammatory chemicals like prostaglandins and other eicosanoids…and then come the impulses to the brain…  Botty-rot results in the bum, and if the brain’s doing nothing much (Oh, focused on computer games… ahh! ) so it all starts to go bananas and you have to move.  Moral here: mechanics turns to chemicals turns to electricity and makes you move… aversive… psychology again… sorry.

Chronic pain can be precise and mechanically patterned….There are plenty more examples, but let’s have a thought for pain that’s beyond the Wrasse cut, the repeated hand-stands and the human-statue’s botty-rot problem.

All pain’s can have a mechanical pattern, even chronic ones.  Chronic pain, and I mean chronic maladaptive pain, can sometimes be incredibly precise and be clearly mechanically patterned.  I tear my hair out when I read papers that define ‘nociceptive mechanism related pain’ as having ‘mechanical pain’ , being well ‘localised’ and having clear relationship to movement and physical stress…, … and then ‘central mechanism related pain’ as being vague, non-mechanical, and poorly localised… I wonder if those who write this stuff and tell clinicians to believe it have ever really listened to patients.  Meow.

To assume that a pain of many years duration is still a tissue problem because it’s mechanically patterned and localised is OK ish to consider…,  but it’s mostly flawed and unhelpful overall.  Why can’t it be a meaningless pain, or a pain that is out of all proportion to the needs of the tissues (which granted may well be scar tissue or degenerate)?  My best argument follows… and comes from researchers with the rare qualities of having ‘listened’ to patients.

Here’s a quote from: Coderre, T. J., J. Katz, et al. (1993). “Contribution of central neuroplasticity to pathological pain: review of clinical and experimental evidence.” Pain 52: 259-285.

( – and note, the authors include Joel Katz and Ron Melzack, researchers who listen to patients!)

‘A striking property of phantom limb pain is the persistence of a pain that existed in a limb prior to its amputation.  This type of phantom limb pain, characterized by the persistence or recurrence of a previous pain, has the same qualities and is experienced in the same area of the limb as the pre-amputation pain.  Case studies of amputees have demonstrated pain ‘memories’ of painful diabetic and decubitus ulcers, gangrene, corns, blisters, ingrown toe nails, cuts and deep tissue injury.’

It’s the same for some unfortunate arthritic pain sufferers who then undergo amputation.  They get phantom arthritic pain, it may come and go with the weather and have feelings of stiffness in the joint just like it used to have… yet there’s no joint there anymore.  Pain related to arthroses in the knee joint is usually seen as a nociceptive mechanism… a fault or problem in the joint… get a new one… maybe we need to think again?

See: Haigh, R., C. McCabe, et al. (2003). “Joint stiffness in a phantom limb: evidence of central nervous system involement in rheumatoid arthritis.” Rheumatology 42: 888-892.

CBT approaches to patients with arthritis related chronic pain and disability have been shown to be effective…

Clinically you have to simply ask the questions … ‘Is this chronic mechanically patterned and well localised pain out of all proportion to the damage done?’  ‘Is it capable of being loaded and not being damaged?’  If you think its scar tissue or degenerate, so what, the key question is:- ‘Is it strong enough to start loading and get fitter?’  And, ‘Is it capable of being exposed to forces and movements that may help it to become less sensitive/desensitised, stronger and more functionally capable?’  The answer is most often yes and vast improvements can be made given the right top-down approach and top-down messages.

Fluid movement and discs.  Repeated movement causing pressure changes in tissues and forcing fluid out so they become less turgid may, in part, be a possible tissue reason to explain quick changes in pain and stiffness. Conversely, lack of movement provides an opportunity for fluid to return and become turgid and stiff again.  The disc, being the largest collagenous and avascular structure in the body, if intact, clearly demonstrates this fluid flow and changing stiffness phenomenon.

You might like to read the following paper about this very topic.  I wrote it way back in 1994…and hopefully note that I’m not the ‘neo-psychosocial’-tissue-hating-fascist that some would have me be.

Gifford, L S 1995  Fluid movement may partially account for the behaviour of symptoms associated with nociception in disc injury and disease.  In: Shacklock, M O (ed) Moving in on Pain.  Butterworth-Heinemann, Australia

In Part 2 to follow fairly soon…. I’m going to review the statement below from earlier and discuss another way of looking at centralization that I hope is reasonable and palatable, bring your shorts or wear sensible underwear… :-

‘Symptoms tend to centralize and eventually diminish as the displaced disk material is relocated and the deformity of surrounding tissues is reduced……’


A final review of some of this… 

  • It’s my belief that the term ‘mechanical pain’ tends to make therapists think of a ‘mechanical problem’ that can only be fixed with ‘mechanical forces’.  I have criticised the notion that rapid improvement in pain while using exercise or mechanical techniques means that the mechanical problem, the tissue dysfunction, is improving.  I gave some examples from this profession as well as others and have attempted to show that this is much more likely to be due to changes in processing, but fluid movement may be involved too.
  • The preferred term: ‘Mechanically patterned pain’ allows the clinician to see that this ‘on-off’ with movement/manual therapy clinical pain presentation can be associated with tissue injury, tissue inflammation, scar tissue and healing, and many degenerative tissue or joint disorders as well.  The term allows pain mechanisms to be embraced and the broader dimensions that always accompany it in every patient every time. It suggests that movement may well help, not only with healing tissue recovery over longer time periods if graded well, but also in the desensitising process.

Centralisation or Centralization… follows in a while…


20 thoughts on “Centralisation, Part 1: Mechanical pain, mechanical diagnosis and the Wrasse bite

  1. Really enjoying your blog Louis; thanks for continually making us think and rethink what is going in us “complex organisms”. Trouble is most of us like simple explanations; for ourselves and for our patients. It would be good to hear more of the way you explain these concepts to different people ( some want and cope with more depth than others, don’t you find?)
    Thanks also for sharing all the links and past articles, i have just dusted off my copy of Moving in on Pain!
    Hope Philippa’s foot is on the mend?!
    PS I don’t think you need fear any diatribe from McKenzie Institute and I for one am looking forward to a reopening of the conversation.

    • Chris, wow, long time, good to hear you and thanks for your kind words and thoughts. You still Milton Keynes? or have I got you in the wrong place?

      1. Regarding explanations complex v simple – agree totally. All in the forthcoming book which is nearing completion… going like a train.
      2. Philippa’s foot is better now, though it took a good month, she had to wear her walking boots a lot as they were the only shoes that were comfy!
      3. re Mckenzie and backlash – well, I think it needs debating and I try to be reasonable and logical. Nice comment today at the bottom of ‘The Mckenzie debate’ page here too. That lass said she was told she had to use the McKenzie system… sounds like the Isle of Wight…(that only makes sense if you’ve seen the recent debate in Frontline about the health authority there spending £46,000 training all the islands physio’s in the mcKenzie system. Ker-ching…! Whoops slipped on the keyboard then…)
      Take care,,


  2. ‘I wrote it way back in 1994…and hopefully note that I’m not the ‘neo-psychosocial’-tissue-hating-fascist that some would have me be’.

    This is still the impression that i have (not of you louis ) but many people who are interested in the complexities of pain and movement.
    On a typical day there are one or two people who fit the tramline diagnostic categories designed to assist the processing of patients in the NHS clinics. Unless i have missed the other 90% and failed to register the black swans/redflags that are creeping through, the rest of my cases yesterday were ‘flare up’s’ in chronic multifactoral lifestyle/chronic stress and OA type problems …The only way to negotiate this typical scenario I have found is to integrate the information i have learned from the pain revolution and the case histories presented by yourself Dave Butler and Mick years ago!
    I had this very articulate lecturer as a patient yesterday who presented with atypical inflammatory reaction in her feet about 6 weeks ago . Complex history in a way and been evaluated by Rheumatology etc but the thing that made the most difference to her were very simple things –issuing crutches with some info on stress/loading/healing times/inflammation/rest what to watch out for , some papers on cns and inflammation ( lots of external stresses which she later informed me of) and what SHE could do ….This to my mind is what we are useful for (and everything has settled down ) …This contrasted 100% with the consultant who said that she likely has x, nothing she can do will make much difference and the history (prev fracture/bilat metatarsal pain and massive increase in loading gorge walking ) had nothing to do with the presentation so she needed methatraxate . The patient said she felt she was sinking into a medicalised role with little control . For a huge amount of people this is exactly what is happening and the only way i can justify my job very often is to use the education to help the willing to move on and challenge a great deal of what has been done or suggested to them.

    Back to your question ….
    Let’s turn our attention to finding out more about normal responses and normal recovery history and timing… Recovery has been done quite well for frozen shoulder, poorly for sciatica and desperately needs doing for carpal tunnel syndrome, tennis elbow….. Achilles tendonitis, plantar fasciitis…. to name a few…
    One woman told me she had carnal tunnel syndrome . However, ignoring the recovery time for this particular case the questions are valid ……..Most are very slow …….many patients and clinicians are totally unrealistic and the pathophysiology is far from straightforward . Much of the thinking is still ‘inflammatory’ see Kahn BMJ sometime in the past . ‘opathies’ strike the middle aged enthusiast and the process of recovery is in months to years . It took me 2 years to be able to be able to spring about alcohol free at a ceilidh dance with achilles (and the Alfredson protocol made no difference and made it worse) . I had tennis elbow too …had an injection ..felt great .. pain came back, lasted a lot longer i.e. well over a year (research says this is often the case)…wrote something up about mechanisms behind injections (central/placebo modulation etc ) not popular ..Much too much emphasis in physiotherapy on learning skills to inject patients in my opinion as vast majority of treatments in non specialist clinics are non inflammatory problems. Still the way to promotion is through ‘doing things to people’, mirroring the orthopaedic interventional model and not the interactive educational communicative process that is much more relevant (see Diane Jacobs excellent blog for further explanation) .

    Looking forward to your book very much …..

    • Ian, as ever, spot on. It would be great if such clinical histories and commentaries could be written up and published…. Topical Issues in Pain 6 perhaps!! ‘Clinical histories, comments and reasoning’.
      A bit like Mark Jones’ book of case histories in ‘Clinical Reasoning for Manual Therapists’ but shifted away from the heavy bias towards ‘technique’. Just a thought!
      I think I said somewhere about my ‘nail-gun’ golfer’s elbow that took over 2 years to go completely… followed building a long fence and using a heavy nail-gun for 3 days….
      I’m working hard on the book.. thanks for looking forward to it!!

      • That’s a good suggestion –there must be a wealth of stories , dismissed as anecdotes perhaps but therein so often lies the interest. Rita Charon calls this narrative medicine and Quinter writes eloquently about the ‘aporia’ of pain (meetings in this space between provider and ‘patient’ create the place for change). In this space there is an interface between neuroscience and the humanities . The writing and research of Benedetii http://www.amazon.com/The-Patients-Brain-neuroscience-doctor-patient/dp/0199579512 and the informative case histories of Oliver Sacks such as a leg to stand on perhaps. This was recently reviewed here http://www.ncbi.nlm.nih.gov/pubmed/22872718 and there are lots of lessons that could inform interactions. I am surprised there is little interest in this side of life but as it doesn’t conform to recent trends in pathways and orthopaedic evidence i shouldn’t be.

        • Nice, what coincidence, both Beneditti’s books sit beside me and I’ve just referenced them in my writing here! Sacks is a great one for describing things but doesn’t ever seem to get into pondering what’s going on. I recently enjoyed a great deal of his Hallucinations book (especially seeing what a LSD tripper he was)…. as well as his ‘musicophilia’ a while back.. What a great listener and narrative writer he is.
          In the last few years I’ve been asking successful patients what the key things were in their improvement and turning their life around… and it’s a lovely question to ask… I found I got stuff like…. ‘When you said stop screwing your face up and try to flow again…’ or, ‘I’d been so fearful of making it worse until you showed me that I was actually doing the movements I feared anyway… ‘ (Patient fearful of bending but sat fully slumped and liked a curl up exercise on all four’s). Or this, ‘When you said my body was strong enough to walk from here to John-O-Groats and back…’ Or, ‘when you helped me to realise I was tensing with all my movements, it took a week to work out what you meant, but once I’d got going with the right head set-up I came on in leaps and bounds….’
          It’s not only what you say, it’s when you say it too.
          These examples could easily have been classed as tissue problems and left to fester…and fiddled with… The first had mild OA knee; the second was an ongoing back pain whose X-rays revealed degnerative changes; the third (J-O-Groats) was one year post cruciate repair; and the last an 18 month post whiplash….
          It’s obviously not the only thing and context, trust etc are massive…The great aporia of pain, fascinating…

  3. Thank you for sharing your thoughts, Mr Gifford.

    Your ‘Introduction to Evolutionary Reasoning’ chapter was a “turning point” for me as a clinician (too many years too late – 2+ years ago); I am grateful that you are freely sharing your previous works and current thoughts on providing care to patients in pain.

    I am currently a clinical instructor for a first-level student in the US…this posting is being added to his reading list.

  4. Mr. Gifford,

    Just discovered this blog through Somasimple. Thank you for this blog – it has become one of my regular browsing sites, and I’ve subscribed/followed. I very much look forward to your upcoming book!

    Jamie Robertson

    • jamie, thanks for your thanks… I’m actually enjoying doing all this and at the same time the book thunders along… If you like the style here, it’s just like the book… hope it works out! Louis.

  5. Thanks Louis another great post. The following quote I may stick to the wall

    “Let’s stop trying to prove our techniques are better than placebo, they’re not… Let’s turn our attention to finding out more about normal responses and normal recovery history and timing…”

    The more we focus on techniques the more we miss the point.

    • Top man! Now, who’s going to get researching?… I always wished I’d kept a diary… the one thing I did do though was to jot down on a pad all those patients who were interesting, or I’d done something clever with, or were total disasters…. for later reference…! good science starts with observations creating ideas, they shouldn’t be so denigrated …… ‘Single case histories’ make us think, especially when someone’s honest and describes an observation, a problem or even a disaster…. not all the ‘how I cured a chronic tennis elbow in one treatment’ ones…
      I had a note from an old patient today saying how stopping taking artifical sweetners had cured her friends MS, apparently the lady was in a wheelchair… soon got out.. and up and away… Wow… or, ‘eh?’ …or, ‘No, really?’…. anyone else observed this..and mystified… ?

  6. Thanks for this Louis, a great read. the following quote I may print out and stable on the wall

    “Let’s stop trying to prove our techniques are better than placebo, they’re not… Let’s turn our attention to finding out more about normal responses and normal recovery history and timing…”

    Physiotherapy does seem to be going round in circles with evidence based practice. The more we study techniques the more we miss the point.

    • Thank you ‘painphysio’! i must say, the two comments so far have been very encouraging, I’ve feared the scathing comment ‘Gifford’s ‘diatribe’ ( A bitter, abusive denunciation!), like I had from the McKenzie faculty back in 2002… I’m trying to be calmer and more persuasive here I hope….Appreciate your re blogging, thanks, Louis.

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