There are two sides to the prognostic coin. 1. The patient gets better / remains better, fully recovers etc and 2. The patient remains painful/disabled, gets worse etc. It is true that psychosocial variables predict a poor outcome as you have pointed out. This has been a major focus in back pain research because it those patients whose symptoms persist who cause governments and insurance companies the greatest cost. Early Identification those who have a poor prognosis does have the theoretical potential to reduce costs, though early cognitive behavioural interventions, and indeed there is some evidence that such interventions do reduce costs and suffering. It is fair to say that over the last 3 decades the psychosocial aspects have received much attention and national treatment guidelines across the developed world have emphasized this[2;3], especially here in New Zealand[1] However, addressing depression and other psychosocial aspects of distress have not reduced the cost of the problem of low back pain and has not provided an effective treatment in the acute or subacute stage. There is value in psychosocial interventions in the persistent back pain population and the PGAP program (see http://www.pdp-pgap.com/pgap/en/index.html ) is an excellent example (but not the only one) of a tested and effective management for these aspects of chronic low back pain. There are also physical signs that identify a poor prognosis. Those patients with radicular pain radiating below the knee, have a neurologic deficit (evidence of nerve root compression), and who have a significantly limited straight leg raising test that provokes the referred pain[18] have a 90-95% chance of having a herniated lumbar disc. While the long term (2 years) prognosis is about the same regardless of whether the patient receives appropriate surgical decompression or awaits the outcome of natural recovery[16;17], the symptoms can be severe for many months. The short term prognosis is better with appropriate decompression surgery / discectomy.

The other side of the prognostic coin is a prediction of which patients do well. While this is of less interest to governments and insurance companies, it is equally important for clinicians and patients. Just being able to say with confidence to a patient that the symptoms are either going to settle spontaneously or can be made to settle rapidly is enormously therapeutic in that it allays fears of permanent disability. A patient who presents with acute onset severe pain that does not radiate into the lower extremity has an excellent prognosis i.e. a 90% chance of being much improved within a week or so. This is the natural history of low back pain. However this is not enough. Clinicians need to be able to rapidly identify those with back pain whose symptoms can be made better rapidly and consistent and it is here that that the physical examination is very helpful. Aside from not having symptoms of depression and psychosocial distress, certain physical findings predict an excellent outcome reliably and consistently, and for a significant proportion of patients. The most researched physical sign of an excellent prognosis (with appropriate treatment) is the centralization and directional preference phenomena[12-14;20;22]. The testing procedure to elicit the centralization and directional preference phenomena is a highly standardized procedure of simple repeated movements and sustained postures[15] which is reliable[4]. The phenomena are also highly specific to the demonstration of discogenic pain as revealed by provocation discography[10]. Logically, when the opposite of centralization of pain symptoms i.e. ‘peripheralization, is revealed in the physical examination, the prognosis is correspondingly poor.

Certain other physical signs assist in identifying pathologies that have a less than good prognosis. The sacroiliac pain provocation tests assist in identifying pain of sacroiliac joint origin[9;11;19], which is a feature of what is generally called pelvic girdle pain[5;7].

It must also be made clear that depression and psychosocial distress affect not only prognosis (as you have pointed out), but also our ability to interpret physical test results[11]. The relation between these psychosocial; factors and physical examination has also been previously explored in some detail [6-8;21;22].

The references I offer here are samples only. There are many more examples. I hope this is helpful.

Reference List

[1] ACC, National Health Committee. New Zealand acute low back pain guide. Wellington, New Zealand: Accident Rehabilitation & Compensation Insurance Corporation of New Zealand and the National Health Committee, 2003.

[2] Arnau JM, Pellise F, Vallano A, Prat N. Editorial Comment: European guidelines for low back pain - a necessary step forward and an opportunity not to be missed. Eur Spine J 2006;15 Suppl 2:S131-S133.

[3] Arnau JM, Vallano A, Lopez A, Pellise F, Delgado MJ, Prat N. A critical review of guidelines for low back pain treatment. Eur Spine J 2006;15:543-553.

[4] Clare HA, Adams R, Maher CG. Reliability of McKenzie classification of patients with cervical or lumbar pain. J Manip & Physiol Ther, Vol. 28 2005. pp. 122-127.

[5] Gutke A, Hansson ER, Zetherstrom G, Ostgaard HC. Posterior pelvic pain provocation test is negative in patients with lumbar herniated discs. Eur Spine J 2009;18:1008-1012.

[6] Gutke A, Josefsson A, Oberg B. Pelvic girdle pain and lumbar pain in relation to postpartum depressive symptoms. Spine 2007;32:1430-1436.

[7] Gutke A, Ostgaard HC, Oberg B. Pelvic girdle pain and lumbar pain in pregnancy: a cohort study of the consequences in terms of health and functioning. Spine, Vol. 31 2006. p. E149-E155.

[8] Gutke A, Ostgaard HC, Oberg B. Predicting persistent pregnancy-related low back pain. Spine (Phila Pa 1976 ) 2008;33:E386-E393.

[9] Laslett M, Aprill CN, McDonald B, Young SB. Diagnosis of sacroiliac joint pain: validity of individual provocation tests and composites of tests. Manual Therapy, Vol. 10 2005. pp. 207-218.

[10] Laslett M, Oberg B, Aprill CN, McDonald B. Centralization as a predictor of provocation discography results in chronic low back pain, and the influence of disability and distress on diagnostic power. The Spine Journal, Vol. 5 2005. pp. 370-380.

[11] Laslett M, Young SB, Aprill CN, McDonald B. Diagnosing painful sacroiliac joints: a validity study of a McKenzie evaluation and sacroiliac joint provocation tests. Aust J Physiother, Vol. 49 2003. pp. 89-97.

[12] Long A. The centralization phenomenon: Its usefulness as a predictor of outcome in conservative treatment of low back pain: A pilot study. Spine, Vol. 20 1995. pp. 2513-2521.

[13] Long A, Donelson R, Fung T. Does it matter which exercise?: A randomized control trial of exercise for low back pain. Spine, Vol. 29 2004. pp. 2593-2602.

[14] Long A, May S. The comparative prognostic value of directional preference and centralization: A useful tool for front-line clinicians? Journal of Manual & Manipulative Therapy, Vol. 16 2009. pp. 248-254.

[15] McKenzie RA, May S. Mechanical diagnosis and Therapy: The lumbar spine, Vol. 1. Waikanae, New Zealand: Spinal Publication New Zealand Ltd, 2003.

[16] Peul WC, Arts MP, Brand R, Koes BW. Timing of surgery for sciatica: subgroup analysis alongside a randomized trial. Eur Spine J 2009.

[17] Peul WC, van den Hout WB, Brand R, Thomeer RT, Koes BW. Prolonged conservative care versus early surgery in patients with sciatica caused by lumbar disc herniation: two year results of a randomised controlled trial. BMJ 2008;336:1355-1358.

[18] van der Windt DAWM, Simons E, Riphagen I, Ammendolia C, Verhagen AP, Laslett M, Devillé W, Aertgeerts B, Deyo RA, Bouter LM, de Vet HCW. Physical examination for lumbar radiculopathy due to disc herniation in patients with low-back pain. Cochrane Database Syst Rev 2008.

[19] van der Wurff P, Buijs EJ, Groen GJ. A multitest regimen of pain provocation tests as an aid to reduce unnecessary minimally invasive sacroiliac joint procedures. Arch Phys Med Rehabil, Vol. 87 2006. pp. 10-14.

[20] Werneke M, Hart DL. Centralization phenomenon as a prognostic factor for chronic low back pain and disability. Spine, Vol. 26 2001. pp. 758-765.

[21] Werneke MW, Hart DL. Centralization: association between repeated end-range pain responses and behavioral signs in patients with acute non-specific low back pain. J Rehabil Med 2005;37:286-290.

[22] Werneke MW, Hart DL, George SZ, Stratford PW, Matheson JW, Reyes A. Clinical outcomes for patients classified by fear-avoidance beliefs and centralization phenomenon. Arch Phys Med Rehabil 2009;90:768-777.

Dear Arnold,

17 years of statistical evaluation of our treatment in our rehab centre for chronic low back pain has not shown any solid predictive parameter (neither physical, neither psychological). What we do see is that depressed feelings diminish significantly when patients regain grip on their body and pain. For us depressed feelings do not have predictive value. (although in some cased depression is so bad the patient cannot lear and perform the exercises, then medication is needed first).

There is a nasty aspect in your question: besides the specific back pain (see marks answer) there is a huge number of patients with 'non-specific' backpain. It is commonly assumed that in these patients no 'specific' physical cause for the complaints can be pointed out. If you cannot find physical causes, what would you select as predictive parameter? Basic parameters as endurance of stiffness are to gross and useless. This is one of the reasons why psychogical factors are found in literature and physical are not.

The simple fact is that we don't know where to look (in the non-specific patients...)

Thank you Dr. Laslett and Dr. Wingerden for your reply. As you have mentioned, most patients whom we encounter are those with non-specific low back pain. Some scientists suggested spinal instability to be the potential cause of non-specific low back pain. Specific motor control exercises have been developed and used in last 2 decades. However, the hypothesis of transversus abdominis and lumbar multifidus co-contraction in reducing back symptoms and preventing recurrence has been busted by recent research. Apparently, centralization phenomenon is a more reliable physical sign to predict the prognosis of certain patients. While a meagre number of physical features can predict clinical outcomes of patients with low back pain, much research has shown the strong influence of psychology of patients or patient-therapist relationship in determining the treatment outcomes. Future PT curriculum should incorporate additional psychological and communication skill training alongside the traditional physical-oriented training to equip our graduates to treat patients holistically.

Dear Arnold,

With all respect I would call your last answer a bit too short fetched. Although the mechanism behind multifidus and transversus are more complex than assumed, it has not been busted, as you call it. The centralisation fenomenon is usefull in specific back pain. I am not sure about the non specific!

I''ll try to come up with a somewhat more complete picture:

The way people use their body, we call behaviour.

Both psychological and physical factors can affect this behaviour:

Examples: .If you are depressed or just in a bad mood, you behave different. If you have a muscle tear, you behave different. If yiou in pain you behave different.

In all these cases your body is doing something in a not regular way. It can be assumed that this abnormal physical behaviour in itself could induce pain.

From this perspective, no matter what the prime cause, if we want to normalize behaviour. People can change behaviour effectively if it is accompanied with positive feedback (and/or emotion).

So to be effective we have to know how we want the person to behave (normalize physical function) AND we have to understand what motivates the patient. BY the way, an important part of this positive feedback lies in the physical improvement and diminished pain a patient experiences if he changes behaviour.

Maybe I am mistaken, but I think there has not yet been much literature on this approach.

Too many studies just focus on physical change or psychological factors. My main point is: they are intertwined and depend on very complex factors!

Hi Dr. Wingerden,

My bad. I used a provocative phrase. I should say that the conventional hypothesis of transversus abdominis (TrA) and lumbar multifidus (LM) co-contraction is oversimplified. A number of recent papers and comments have raised the doubt about this hypothesis.[1,2,3] Specifically, feedforward onset of TrA during a contralateral shoulder flexion seems to be a directional biomechanical response.[3] TrA doesn't seem to activate prior to other trunk muscles regardless of the shoulder movement directions. Further, evidence also shows that most pregnant women who experienced low back pain during their pregnancy recovered within a week of delivery.[2] It is a weird phenomenon given that the function of their distended abdominal muscles are not supposed to fully recover during that short period. New evidence also reveals that there is a great intraindividual and interindividual variability in trunk muscle recruitments for individuals with and without low back pain.[4] Alternation of TrA onset doesn't seem to predict post-treatment clinical outcomes.[5] In short, spinal stability involves complex co-ordination of all the trunk muscles rather than a simple co-contraction of two innermost muscles. However, in last two decades, we have overemphasized the importance of TrA and LM co-contraction in our practice. Spinal stabilization/motor control exercises are so appealing to thousands of physiotherapists. We somehow forget that co-contraction of muscles may not be the best strategy for our daily activity. A recent meta-analysis has showed that motor control exercise is not better than other types of back exercises in the long run.[6]

I agree with you regarding the complex behavioural change and low back pain. There is a trend to study the patient-therapist interaction and treatment outcomes. It may be a promising research direction because patient-therapist relationship may be an important factor to educate patients and to change their behaviour.

References

1. Stokes et al., Abdominal muscle activation increases lumbar spinal stability: Analysis of contributions of different muscle groups. Clin Biomech 2011;26:797-803.

2. Lederman. The myth of core stability. J Bodywork Move There 2010;14:84-98.

3. Morris et al., Corset hypothesis rebutted — Transversus abdominis does not co-contract in unison prior to rapid arm movements. Clin Biomech 2012;27:249-254.

4. Hodges et al.,New insight into motor adaptation to pain revealed by a combination of modelling and empirical approaches. Eur J Pain 2013; Epub ahead of print.

5. Vasseljen et al., Effect of core stability exercises on feedforward activation of deep abdominal muscles in chronic low back pain: a randomized controlled trial. Spine 2012;37:1101-1108.

6. Wang et al., A Meta-analysis of core stability exercise versus general exercise for chronic low back pain. PLoS One. 2012;7(12):e52082.

Dear Arnold,

I almost fully agree with your point of view, almost. I agree that stability of the spine is more complex than some simple muscle co-contractions. On the other hand Hodges and friends have pointed out some significant principles which need more research. That motor patterns change (in back pain) is intriguing. From what we experience from our patients (over 17 years about 10.000 back and pelvic pain patients) we have the assumption that the altered patterns of multifidus and transverus might not be the cause but more a consequence of what is happening in the spine, leading to some vicious circles.

Another point of disagreement is the amount of woman that experience lasting problems in their pelvic area after childbirth. This number is bigger than often presumed. I agree that the majority recovers within weeks after labor, but there remain many with non-optimal functioning spines and pelvises. Because in many countries it is considered normal that the mechanical capacity of the pelvis of a women after laber decreases, their discomfort is considered normal. However, this is not! Proper training can help to improve function of the pelvis in these woman signficantly. In conclusion and addition to my previous mail: physical dysfunction (i.e. altered motor patterns) plays an important role in back and pelvic pain. We still don't understand the exact mechanisms and focussing on altered/delayed multifidus only is an oversimplification. This still is no argument to leave physical factors out of the equasion of finding predictive parameters for back pain recovery. On the contrary, besides the psychological/behavioural factors, the physical aspects need more attention and reseach. Especially since experiencing pain free motion is the optimal psychological stimulus for back pain patients. Proper knowledge of physical function allows therapists to let their patients experience motion without of less pain!

@Arnold and Jan-Paul. This is an excellent discussion and the great majority of what is being said is right on the mark. Arnold - your comments on the limitations of the traditional TransAb / multifidus schema are spot on. However I am not sure how it is that my comments about non-specific back pain and specific back pain are apparently being misunderstood. For example from Jan-paul "..The centralisation fenomenon is usefull in specific back pain. I am not sure about the non specific!.." This statement reverses the correct order of things. The centralization phenomenon is not 'useful in specific back pain', it is a means by which non-specific back pain is rendered specific for those that display the sign. Being a very common finding (estimates vary with chronicity and variations on the definition of centralization), this single clinical sign reduces the proportion of cases who should be labelled as non specific from the usually stated 90% to as much as 30% (if 75% of patients display the centralization sign). It is of course not the only clinical finding that is highly specific for a particular patho-anatomic diagnosis. The SIJ provocation tests are highly sensitive and have moderate to high specificity for pain of SIJ origin (see our own work and that of Peter van der Wurff[12]). The clinical findings of motor deficit, reflexopathy are also highly specific to nerve root compression, though the research that supports this contention is rather dated now and should be replicated using better quality of trials[11]. Also there are imaging signs that are highly specific like the high intensity zone seen on MRI [4;7;10] and herniation of disc material[5;13]. The observation of Modic changes in the vertebral bodies of the lumbar spine seen on T2 weighted MRI is also strongly associated with pain – discogenic pain[1-3;6;8]. All these non invasive clinical test procedures reduce the proportion of non specific LBP cases to a very manageable level – probably in the order of 20-30% of subacute cases and maybe to 50% of chronic cases[9].

The points made by Jan-Paul regarding the proper integration of the physical and psychological aspects of pain and pain behaviour are noted and I agree entirely. However the statement “..In all these cases your body is doing something in a not regular way. It can be assumed that this abnormal physical behaviour in itself could induce pain..” cannot be left uncommented upon! This is an assumption that implies a definite causal link and we should be wary of any such statement. There are literally thousands of people not experiencing back pain of any sort of pain, whose body mechanics are grossly abnormal. Look at cerebral palsy, Parkinsons disease cases just to name two. That certain abnormal biomechanical anomalies are associated with pain is reasonable and may be sustained with reference to appropriate literature, but to assume that these are causal is not possible unless one can say that these findings are sufficient and/or necessary to produce LBP. I have taken the traditional meaning of causation here to mean that causal requires necessary and sufficient conditions to me met. To my knowledge, aberrations in biomechanical function have not met either sufficient or necessary condition status, but please correct me if I am wrong.

Reference List

[1] Albert HB, Kjaer P, Jensen TS, Sorensen JS, Bendix T, Manniche C. Modic changes, possible causes and relation to low back pain. Med Hypotheses 2008;70:361-368.

[2] Albert HB, Manniche C. Modic changes following lumbar disc herniation. Eur Spine J 2007;16:977-982.

[3] Albert HB, Manniche C, Sorensen JS, Deleuran BW. Antibiotic treatment in patients with low-back pain associated with Modic changes Type 1 (bone oedema): a pilot study. Br J Sports Med 2008;42:969-973.

[4] Aprill C, Bogduk N. High-intensity zone: a diagnostic sign of painful disc on magnetic resonance imaging. Br.J.Radiol., Vol. 65 1992. pp. 361-369.

[5] Boos N. The diagnostic accuracy of MRI, work perception, and psychological factors in identifying symptomatic disc herniations. Spine 1995;20:2613-2625.

[6] Braithwaite I, White J, Saifuddin A, Renton P, Taylor BA. Vertebral end-plate (Modic) changes on lumbar spine MRI: correlation with pain reproduction at lumbar discography. Eur Spine J 1998;7:363-368.

[7] Hyodo H, Sato T, Sasaki H, Tanaka Y. Discogenic pain in acute nonspecific low-back pain. European Spine Journal, Vol. 14 2005. p. 573.

[8] Kuisma M, Karppinen J, Niinimaki J, Kurunlahti M, Haapea M, Vanharanta H, Tervonen O. A three-year follow-up of lumbar spine endplate (Modic) changes. Spine 2006;31:1714-1718.

[9] Laslett M, McDonald B, Tropp H, Aprill CN, Oberg B. Agreement between diagnoses reached by clinical examination and available reference standards: a prospective study of 216 patients with lumbopelvic pain. BMC Musculoskelet Disord., Vol. 6 2005. p. 28.

[10] Peng B, Hou S, Wu W, Zhang C, Yang Y. The pathogenesis and clinical significance of a high-intensity zone (HIZ) of lumbar intervertebral disc on MR imaging in the patient with discogenic low back pain. Eur Spine J 2006;15:583-587.

[11] van der Windt DAWM, Simons E, Riphagen I, Ammendolia C, Verhagen AP, Laslett M, Devillé W, Aertgeerts B, Deyo RA, Bouter LM, de Vet HCW. Physical examination for lumbar radiculopathy due to disc herniation in patients with low-back pain. Cochrane Database Syst Rev 2008.

[12] van der Wurff P, Buijs EJ, Groen GJ. A multitest regimen of pain provocation tests as an aid to reduce unnecessary minimally invasive sacroiliac joint procedures. Arch Phys Med Rehabil, Vol. 87 2006. pp. 10-14.

[13] Vroomen PC, Van Hapert SJ, van Acker RE, Beuls EA, Kessels AG, Wilmink JT. The clinical significance of gadolinium enhancement of lumbar disc herniations and nerve roots on preoperative MRI. Neuroradiology 1998;40:800-806.

Dear Mark,

You are absolutely right on the centralisation part. You can see i am not McKenzie educated. Sorry. The discussion on the abnormal physical function is indeed more subtle. My remark on physical dysfunction in relation to pain was oversimplyfied. I'll try to be more specific. Our bodies have some over-capacity. This means that we don't have one optimal function but we can shift a bit. However this shifting often means our capacity is somewhat less. In the examples of Mark about the cerebral palsy, these people can live their life without pain, but in most cases their physical capacity will be, in some way limited. If such a person would attempt to perform on a non-palsy level chances are there will be discomfort.

In other words, I agree with Mark that not all abbarant function per definition leads to pain. Non-optimal function however does alter physical capacity, which increases the chance of overload, and consequently pain. By the way it is in this area where also psychological aspects come in: when your perception on your physical ability is not within range with your true physical capacity this may lead to overburden and pain.

In a general clinical standpoint, it is intuitive that there should be predictive value. For purely mechanical back pain and no radiculopathy, the prognosis should be good. Physical examination may not be as representative and accurate in predicting rapid vs slow recovery. This may be dependent on the mechanism of injury, age and other psychosocial factors.

If back pain is related with neurological deficits, that is where PE may be predicitive. But the support for further diagnostics may be the best way.

Either way, predictive factors are great when you have stratified your patient population and striked the confounding variables, my opinion.

I really enjoy our discussion. Mark - I agree with you insightful comments. Interestingly, some recent longitudinal studies found that Modic changes might not be associated with the clinical course of LBP [1,2]. Once again, it shown that spinal pathology may not totally related to pain perception, which involves complex psychological, physiological and physical interaction. Regarding the causal relation between aberrant biomechanical function and LBP, I agree with Jan-Paul that it may increase the risk of future LBP injury but it has to be proven by longitudinal studies, which is very difficult to prove once we pool the data from different participants with diverse biomechanical patterns.

Based on our discussion, I note that subdividing our patients into different subcategories based on specific physical findings (radiculopathy, centralization phenomenon or SIJ symptoms) may have a predictive value. However, for those patients without these clinical signs, their prognosis may vary. Correct me if I am wrong.

References

1) Keller et al., Are Modic changes prognostic for recovery in a cohort of patients

with non-specific low back pain? Eur Spine J 21:418–424.

2) Jensen et al., Is the development of Modic changes associated with clinical

symptoms? A 14-month cohort study with MRI. Eur Spine J 21:2271-2279.

Interesting biomechanical perspective. Not published yet but we finished golf swing study with lumbar disc degeneration and currently the literature is being peer reviewed.

There is a kinematic difference between groups that is statistically signficiant.

To determine if this "kinematic fingerprint" that we have identified has clinical value remains to be seen.

Modic changes has some values in the clinical setting, but it is safe to say it may affect treatment outcome as well, my biased opinion.

Yes

@ Arnold. Indeed, not all Modic changes correlate with pain on discography - only type 2 as I recall. Does the Keller et al article look at prognosis for different Modic types or just all Modic types? If they lumped them all together, then I would expect that the 'all Modic' category would not be prognostic.

Keller et al. analyzed Modic Type I and Type II change separately. However, both Type I and Type II Modic changes didn't did not associate with the course of pain, FABQ and function. It might be partly explained by the high drop out rate (40% and 60% dropped out at 6-week and 1-year follow-up, respectively). However, more longitudinal studies are warranted.

Thanks Arnold. You saved me the effort of re-reading the article. Cheers!

You are welcome

Dear Arnold

We have performed a study in primary care looking at physical examination to predict long term outcome in patients with non-specific low back pain. Measured at a physical examination 4 weeks after the patients initial visit, several physical measures were predictive of future outcome. As in many other studies, physical facotors assessed at basline did not predict future outcome.

We have published our results see reference below.

sincerely,

Paul Enthoven

ref:

Paul Enthoven, Elisabeth Skargren, Görel Kjellman and Birgitta Öberg

COURSE OF BACK PAIN IN PRIMARY CARE: A PROSPECTIVE STUDY OF

PHYSICAL MEASURES. J Rehabil Med 2003; 35: 168–173

All biopsychosocial aspects must be taken into consideration in the treatment of low back pain.

The theory proposes that may be different in practice.

http://www.jospt.org/doi/abs/10.2519/jospt.2012.42.4.A1#.VPH7I_nF9q8