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RE: Classification Scheme vs. Biomechanical model
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RE: Classification Scheme vs. Biomechanical model - November 25, 2007 2:43:32 PM
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steve
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From: victoria, bc Canada
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Hi Doug,
I agree with you that we are movement specialists and biomechanics are very important to what we do but I think this arguement is being polarized somewhat.
When I refer to the biomechanical model I am refering to a system that suggest that pathology and treatment decisions can be made through a focus on palpating movement in specific segments and directions in the spine and minimizes or ignores important other clinical factors that have been established through sound research. A nice example would be the emphasis placed on alar and transverse ligament testing while most therapists have no idea about the Canadian C-spine rules or Nexus protocol for ruling out fractures. Here we have a case where emphasis has been put on tests that have unknown importance if positive or negative and identify very rare pathology. This stated, we certainly should be aware of these conditions and be questioning how to rule out the presence of the conditions through the clinical exam but we should also be more aware of a clinically relevant fracture that can easily be ruled out through a couple of quick tests.
Certainly research has established that motion palpation contributes to our clinical decision making, just that it isnt nearly as important as what we once thought. There no longer seems to be a need to treat as specifically as we once thought either. Even in the example of the ACL tear, the history contributes more to our decision making than the actual Lachman test that has quite variable reports of its sensitivity and specificity (Between .55 to .99 depending on what study you read). I also wonder why no study has ever established that certain clinicians palpation skills are better than others with respect to the spine and would suggest that some of these therapists who feel they can palpate specific pathology are often misleading themselves in establishing a faulty diagnosis.
Your comment about theory based models - "Some aspects might have very strong support but some critical aspect further down in the logic train may be fatally flawed." reminds me of a great post a guy named Bobcat did years ago on this site. If I could find it I would link it.
Steve
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RE: Classification Scheme vs. Biomechanical model - November 25, 2007 6:38:34 PM
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SJBird55
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Doug, point taken, but my intent wasn't to slam biomechanics... just some of the manual palpatory crap that goes on - and yes it does. It is prevalent here in the States.
Steve or anyone... where is that Cat? I know I'd enjoy a blast from the past. Bobcat was my favorite. :)
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RE: Classification Scheme vs. Biomechanical model - November 26, 2007 1:50:31 AM
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avalon
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quote:
Avalon, are you trying to say physical therapy does not work for LBP?
Not really. I'm just saying that a limited model which is focussed on back zones will fail in many instances.
Many PTs treat LBP bu I do not. I encounter patients that experience pain in the lumbar area with/without real physical problems.
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RE: Classification Scheme vs. Biomechanical model - November 26, 2007 1:44:50 PM
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Bournephysio
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Proud, you may want to read my comments before responding. I said nothing about specific joint play.
SJ, I didn’t think it was your intention but unfortunately I think that reading “the biomechanical model sucks” leads to biomechanics sucks in many minds so I thought that point needed to be made.
Hey Steve,
“but I think this arguement is being polarized somewhat.” I really don’t get this. My first point was that the “biomechanical model” is anything but. Proud seems to want me to defend this model (and is twisting my arguments along the way).
I agree with much of your post but I will say a couple of things. “I am referring to a sytem that..... ignores important other clinical factors” There is no reason for this. In fact the system is set up to accommodate this. The Canadian C-spine rules would fit perfectly in the scanning exam. The clinical prediction rules for manip fit in the “biomechanical exam.” When I started in the Canadian system it was in a state of flux. There was a great push to be more evidence based. New material such as Hodges work was being incorporated. At the 2004 IFOMT, people like Watson, Fritz, Kahn, and Moseley presented. Since then, I think only Kahn’s work has been completely incorporated. The Canadian system has stagnated and stopped incorporating this new material. My wife and a couple of people that I work with just took V4 (the first spinal manips class). I was astonished to hear that the clinical prediction rule for manipulation was never mentioned. At the very least it is the best evidence we have that manipulation even works.
“I also wonder why no study has ever established that certain clinicians palpation skills are better than others with respect to the spine and would suggest that some of these therapists who feel they can palpate specific pathology are often misleading themselves in establishing a faulty diagnosis.”
There are a few different points here. The primary reason that no study has established is that we rarely study this properly not only in the spine but in the periphery as well. We tend to concentrate on reliability and spend little time with accuracy. Even while training, most of our feedback is from other therapists not gold standards. Sometimes we get lucky and can correlate mri or surgery findings with our testing but this isn’t overly common. Manipulation is another point when you can get feedback on technique and has convinced me that motion palpation can be valuable especially for the neck (you can’t/shouldn’t just wind people up like you can do in the lumbar spine). Proper technique gives you a much better chance of successfully manipulating the spine with as little force and amplitude as possible. The second part of the comment about palpating specific pathology has two components. I have no doubt that some therapists convince themselves that they are feeling something that doesn’t exist (e.g. phantom movements of the cerebrospinal fluid). It is more common that PTs ascribe the differences that they feel incorrectly to a specific pathology. If you can manip a joint (even the “wrong” one) and get an immediate improvement in ROM or pivms or pavms what do you think caused the restriction? Joint adhesions??? not likely. I think that there is little doubt that motion palpation in general is a skill and as such you would expect differences between different therapists as well as differences with training and experience.
Doug
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RE: Classification Scheme vs. Biomechanical model - November 26, 2007 4:44:43 PM
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proud
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Fair enough Doug,
But you said this:
quote:
...It has long been known that you can’t reliably determine if a segment is rotated. I have not seen this in the Canadian system since I’ve been taking courses so around 10 years
Which had me under the impression that you were unaware of much of the specific joint play taught within the system. I mis-interpreted. My apologies.
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RE: Classification Scheme vs. Biomechanical model - November 26, 2007 6:24:11 PM
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Crevidence
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I like the definition of the biomechanical model for this thread as taken from steve
"When I refer to the biomechanical model I am refering to a system that suggest that pathology and treatment decisions can be made through a focus on palpating movement in specific segments and directions in the spine and minimizes or ignores important other clinical factors that have been established through sound research".
Summing up what I have absorbed so far in the biomechancial model vs. classification scheme thread.
The classification scheme is useful for treating a lot of pt.'s.
SJbird:
The classification system discussed does seem to cover the majority of the patients seen in therapy except those in chronic pain with a highly sensitized nervous system or those with (+) slump testing or those with high levels of fear.
There is not much research being conducted to support what is being taught in many of the "biomechanical" courses
Kaden
".....regarding research on the biomechanical model - I can't argue - there is very little. I think this is two fold
1) Hard to do specific biomechanical research and as allready pointed out not all that reliable.
2) Many teaching this model are not doing much research with I agree is a problem
Keep things simple/evidence based and complexity does not equal expert..
Steve
The assumption in the physiotherapy world is that complexity is the realm of the expert clinician and enables them to improve their outcomes by sifting through complex theories and testing with significant detail and variations on each test (Ie. an upper limb tension test sequencing or a pivm in multiple planes of movement etc.). The interesting thing is that it now seems the more data we collect and the more intricate the testing the poorer our decision making. This is called retrospective clinical reasoning, where all the data is collected and then looked at to then make a decision with respect to diagnosis and treatment. Essentially, so much data is collected without knowing its diagnostic properties that "Noise" is created and red herrings are chased.
Certain motion palpation tests for the lumbar spine are valid for possibly identifying clinical hypermobility/instability but not hypomobility. A valid test does not always need to be reliable.
Bourne
PA’s are a motion palpation test (and a paivm in some systems). flexion/extension pivms have use for diagnosing clinical hypermobility/instability and have published sensitivities/specificities.
People probably can't determine manually if a segment is FRS etc..
SJ
one really can't feel that a segment is rotated, flexed or sidebent. ;) Some therapists THINK they can feel it, but research indicates they really can't or aren't.
Any flaws in my take home message so far.
Avalon, why do you not treat LBP and why does focusing on limited back zones fail in many instances. There is a spine surgeon in my area that I think ascribes to this. He says life is therapy.
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RE: Classification Scheme vs. Biomechanical model - November 26, 2007 10:05:46 PM
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proud
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Simply had to say that I think your summary was accurate crevidence. Although I do not agree with the spine surgeon in your area....of course I imagine the spine surgeon is only a little uncomfortable with some recent literature concerning the value of spine surgery....
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RE: Classification Scheme vs. Biomechanical model - November 26, 2007 10:06:09 PM
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Kaden
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Can someone share with me literature that demonstrates that subgrouping patients provides superior outcomes to PT's providing specific manual assesment?
I agree that for one to say a segment is flexed/rotated etc is very difficult and most likely not possible.
But, many in this post have indicated or at least suggested that a subrouping/classification approach provides superior outcomes to those practicing the "biomechanical" model.
In all the studies I read (primarily Fritz et al is what I am seeing) they are comparing subrouping to a control group receiving general aerobic activity, advice that LBP usually improves and AROM exercises.
It is a leap to make the assumption that these outcomes mean subgrouping is superior to those practicing the so called "biomechanical" approach.
Thanks for the input
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RE: Classification Scheme vs. Biomechanical model - November 26, 2007 10:58:56 PM
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jlharris
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I would have to say that the sum total of literature that PT, in general, for LBP is no more effective than chiropractic, accupunture, simple education, etc, would tell us that the way we've been treating LBP is limited and not very effective. And if you most PT's recieved the same education I did, it was based on trying to determine specific motion restrictions at a specific level, and then fixing that.
I also know that Childs et al have looked at LBP pt's that fit the manip CPR, randomly assigned them to a manip group (matched treatment classification) and, IIRC, a general exercise group (non-matched). Not only did the MATCHED group do better, but the non-matched group got worse.
I also read a study on neck manip and chiropractic. I bring this up because chiros tend to also ascribe specific position and/or movement faults to specific levels as the "problem". In summary, DC's were allowed to manip the C-spine as they're exam dictated for one group, and the other group, a computer randomly assigned the level and manip to be done. Surprise! No difference betweent he two groups.
No smoking gun there, but, IMO, enough to make one seriously question the need for years of continueing ed to learn something that apparently is unreliable, and most likely won't allow you to achieve superior results from just guessing and maniping.
_____________________________
Jason L. Harris, PT, DPT
My PT Blog
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RE: Classification Scheme vs. Biomechanical model - November 27, 2007 12:17:44 AM
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steve
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Hey Doug,
Thanks for the response... What your saying sounds like what I'm thinking, if that makes any sense. The upper quadrant screening exam is a great way to rule out serious pathology and you would think that every effort would be made to incorporate something like the Canadian C-spine rule while questioning some of the other more traditional screening tests. It would also be helpful to see therapists learning more about likelihood ratios etc so they could incorporate them into decision making. My experience has been that his information isnt even on the radar for the most part with the Canadian system.
Your right about the reliability testing for manual palpation - it has a lot of things working against it with any research study; the 20 or so studies done of the SI joint that consistantly show lack of inter rater reliability confirm this. If there is no gold standard available what are we testing for and how is it contributing to our decision making? Does it matter? I think most of the evidence suggests that hypermobility matters a fair bit and hypomobility a little bit but I wouldnt hang my hat on either one on their own. For me, its a question of weighting in the decision making process and I give it far less than other components of the examination.
I'd agree with you on the palpation of the neck, it certainly feels like you can palpate more and it would make logical sense that it isnt as accepting of a global wind-up technique as the l-spine but based on the research study JLHarris refers to I am again hesitant to put too much worth into identifying a specific segmental level.
With respect to the motor skill level of the practicioner, again I think its importance has been over valued by the physiotherapy community. I believe it feels better for the patient and there is greater confidence potentially from a patient perspective but the research would suggest that it doesnt change outcomes significantly, particularly in situations where standardization has been used to identify patients amenable to treatment. Josh Cleland just published a paper on thoracic spine manipulation similar to the l-spine CPR where novices performed as well as experienced clinicians. Where does this leave us (From my perspective)? I would suggest more time be spent on incorporating well done research into our practice paterns and some but nearly as much time on a few key techniques for manual therapy... but just my 2 cents worth.
Hows school going?
Steve
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RE: Classification Scheme vs. Biomechanical model - November 27, 2007 1:47:03 PM
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Kaden
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Jason,
Good points. However, it still doesn't show any direct evidence that the classification model is superior to PT's providing specific manual assesment. Fritz et al comparing subrouping patients that fit into a manip category with general exercise is like comparing oranges to apples - the intervention was not even close to the same.
I am not arguing against thier results. I think it is valuable to point out that subrouped patients have better outcomes than non-subgrouped for the future of how PTs will look at evaluating patients. However, many in this post suggested that subgrouping patients provided better outcomes than the biomechanical model. That may be their perspective but there is no evidence to support this.
I can find hundreds of studies in the literature showing manual therapy plus exercise intervention is better than exercise alone. Does that validate the biomechanical model - not even close. It simply implies MT pluse exercise many times is more valuable than exercise alone. Just as studies comparing a specific subgrouped population to a general exercise control group does not prove that subgrouping is better specific manual assesment. It just proves that subgrouping patients provides better outcomes than a general exercise group.
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RE: Classification Scheme vs. Biomechanical model - November 27, 2007 3:31:19 PM
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jlharris
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However, it still doesn't show any direct evidence that the classification model is superior to PT's providing specific manual assesment.
I disagree. What do you use to determine when to manip vs stabilize vs using a direction specific AROM approach? Palpation? These studies are showing that A. -possibly- a fair number of pt's are not going to get the treatment that best fits them and b. those who don't will do worse because of it.
the intervention was not even close to the same.
That's the point. Read studies on LBP treatment and 90+% will show that one specific intervention was no better than the other. eg exercise vs accupunture, manipulation vs education, exercise vs estim, etc. The point, again, is if one doesn't match the patient up with the treatment that best fits them (treatment based classification) you'd do just as well using MFR or CST. It all migrates to the median.
However, many in this post suggested that subgrouping patients provided better outcomes than the biomechanical model. That may be their perspective but there is no evidence to support this.
Again, I think the evidence that shows that we are not doing any better than CST is a HUGE indicator that the complex biomechanical model we were all taught in PT school hasn't seperated us in terms of providing superior results compared to any other crock being doled out for LBP. Subgrouping is a first step is admitting there is not one magic bullet for treating LBP (ie, PRI, Mekenzie, Mulligan, Paris, Sharman, etc) and that knowing which pt's need which approach is the key to optimal outcomes.
IMO, I think we need to step away from our current "My guru is better than you guru" battle and realize the problem is that it doesn't matter what guru you follow, your outcomes aren't better than the next guru's. We need to look at what is similar, what is different, and which type of pt's respond best to those similarities or differences; not take 15 con-ed classes to recieve a certifaction stating you can palpate and dx something that is most likely not there.
It just proves that subgrouping patients provides better outcomes than a general exercise group.
My question then, to you and everyone in general: Are you subgrouping? If you are than this whole back and forth conversation is moot. We know that we don't have a full compliment of "classifications" and therefore it's up to our expertise/experience/clinical knowledge to determine the best plan of care. You could do a dance over your LBP pt during the eval, but as long as you also see how long they have had pain, does extend below their knee, what is their hip IR, HYPOMOBILITY at any level, and FABQ score (or replace with stab CPR criteria) to allow for optimal treatment based on a classification, you are golden. Heck, even check LLD! (sorry, reference to another thread).
_____________________________
Jason L. Harris, PT, DPT
My PT Blog
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RE: Classification Scheme vs. Biomechanical model - November 27, 2007 3:43:11 PM
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Kaden
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Hey Jason,
good stuff. I wasn't trying to knock the subgrouping system. I subgroup and feel it works well and I get better outcomes. I was just trying to make the point that it is a bit of a stretch to imply that the evidence showing subgrouping works, proves that specific manual therapy doesn't work.
Again, here we go with the "palpation" and treat scenario. I don't know who is using that and to assume all manual therapist using specific assesment rely only this to treat is flat out wrong.
I use evaluation, a cluster of special tests first to subgroup patients. And then if I decide it is a local lumbar problem that may benefit from mobilization I will to a more specific biomechanical assesment.
Do I need to be that specific, probably not, but b/c evidence shows you don't again does not mean you get worse outcomes choosing to do so.
In summary,
I still don't think there is enough evidence to say a subgrouping approach is superior to those doing specic assesment and manual therapy.
Let's stop assuming that every manual therapist not using CPR and subgrouping is simply palpating and treating with some manual intervention. They may not be using the same subgrouping as some but as stated above are using subjective plus a cluster of tests to lead them down a particular path which may or may not be a manual therapy intervention.
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RE: Classification Scheme vs. Biomechanical model - November 27, 2007 4:12:54 PM
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steve
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Kaden,
Here's the thing - everyone subgroups. If you practice CST you subgroup into different treatment approaches within your model of practice. Studies using "Typical physiotherapy" has the therapist subgrouping on their individual preferences. The problem is is you just "Subgroup" based on experience and unknown variables in clinical testing but dont use any evidence to create these groups you are doomed to perform no better than all those therapists in randomized trials where therapists treat use "Typical physiotherapy" - look what a black eye that has been on our profession.
Steve
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RE: Classification Scheme vs. Biomechanical model - November 27, 2007 4:23:23 PM
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Kaden
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Steve,
Point taken. But show me the study where "typical physiotherapy" in studies is a clinician subgrouping and choosing the intervention they would like. When we compare things to aerobic exercise and general exercise and call this "typical physiotherapy" are think we are missing the boat.
I am all for developing criteria for specific subgrouping. Lets just not compare it to a general exercise and posture education group. Why not put it to the test against experienced therapists choosing whatever exercise, manual technique, etc they want and compre outcomes.
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RE: Classification Scheme vs. Biomechanical model - November 27, 2007 7:20:09 PM
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jlharris
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Kaden, first I'd like to thank you for the level headed approach you've maintained in all this. I know (reading back) this thread has been very us vs YOU. Personally, I'm not meaning to do that and try not to use the pronoun YOU.
Why not put it to the test against experienced therapists choosing whatever exercise, manual technique, etc they want and compre outcomes.
Here's the problem with that. If everyone is able to do what they want, or, what they feel is "best" then there is no reproducibility. This is a key to developing good outcomes across the profession. Very broad analogy - if you went to your MD for chest pain, would you want him/her to choose whatever treatment they want. Or, one that is standardized across the profession to achieve the highest consistent outcomes?
Now I'm fairly sure that's not the treatment philosopy you meant to portray in the above sentence, but I feel it helps illustrate an important point in regards to the need to standardize PT care to achieve consistent, expected outcomes whether you see me or Joe Blow in California. And relying on an individuals "expertise" will not allow our profession to do achieve that goal.
< Message edited by jlharris -- November 27, 2007 7:23:16 PM >
_____________________________
Jason L. Harris, PT, DPT
My PT Blog
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RE: Classification Scheme vs. Biomechanical model - November 27, 2007 8:32:28 PM
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Kaden
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Jason,
I agree. Developing standards across the PT profession should be the goal and I hope therapy continues to go in that direction. So, that is why I agree subgrouping patients using reliable evidence should become the standard. Standardizing care would help marketing as well and the publics perception of what we do b/c we would no longer have such a wide variety of treatments for essentially the same problem -LBP. Joe blow would be able to answer the question - what does a PT do? So again, I am in full agreement with standardization.
However, I still don't think the evidence is there to condemn the biomechanical model (and to clarify again when I say that I am not talking the DO model of palpate and mob) is there yet. We may have to agree to disagree about that. I know you extrapolate (which I think can be a stretch from many of the control groups in these studies) from other studies that the biomechanical model produces worse outcomes as we have not as a profession had great sucess treating LBP. However there is no direct evidence IMO to show that those using the biomech approach get worse outcomes or if they could even get better outcomes.
Bottom line though - I agree we should be subgrouping with use of best evidence out there and as you allready pointed out then maybe it doesn't matter how we approach the joint manip or mob from that point. If I feel more comfortable and confident using the specific approach and you using a more general mob or manip approach then so be it. The important thing is that the correct treatmet was selected for the given client based on appropriate classification. ....and I have stated this throughout the post that I agree with subgrouping. I was never trying to be the defender of the biomechanical model of palpate and mob.
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RE: Classification Scheme vs. Biomechanical model - November 27, 2007 8:40:06 PM
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Kaden
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Just an FYI for everyone that has chimed in on the debate. Naiomt is discussing spinal manipulation at it 2008 anual meeting featuring speakers from both side of the debate. Included are Josh Cleland and Tim Flynn so could be good stuff related to this post if anyone is interested. NAIOMT Symposium - 2008
Topic: Spinal Manipulation Saturday, April 12, 2008 Portland, Oregon Featured Speakers Include: Erl Pettman, Tim Flynn,
Peter Huijbregts, Josh Cleland , Laurie McLaughlin *Additional pre and post Symposium courses will be added!
Check back for more info!
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RE: Classification Scheme vs. Biomechanical model - November 27, 2007 9:51:23 PM
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Crevidence
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quote:
ORIGINAL: steve
Kaden,
Here's the thing - everyone subgroups. If you practice CST you subgroup into different treatment approaches within your model of practice. Studies using "Typical physiotherapy" has the therapist subgrouping on their individual preferences. The problem is is you just "Subgroup" based on experience and unknown variables in clinical testing but dont use any evidence to create these groups you are doomed to perform no better than all those therapists in randomized trials where therapists treat use "Typical physiotherapy" - look what a black eye that has been on our profession.
Steve
Steve,
This stuff is profound. There are almost 1400 hits on this thread at this point. Do you realize how many minds you are expanding with this stuff? There is probably a 20 yr PT veteran right now trying to figure out how to subscribe to JOSPT while simultaneously throwing out his "course manuals".
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RE: Classification Scheme vs. Biomechanical model - November 27, 2007 9:52:54 PM
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jlharris
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Great points Kaden. Thanks for the info on the NAIOMT symposium.
_____________________________
Jason L. Harris, PT, DPT
My PT Blog
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