Is it all just too bloody complicated?

I’ve just got back from the ESMAC-SIAMOC meeting in Rome. We’ve been entertained royally for three days in the aulas and cloisters of the Thomas Aquinus University. It has once more been a fantastic opportunity to network and exchange ideas and on one level I come back rejuvenated and inspired.

I say “on one level” because on another level I’ve also come back somewhat disappointed – disappointed because there was little in the scientific programme which left me feeling I understood things better than I did before I arrived. A large number of papers could be summed up by the conclusion, “we understand this area less after performing this research than we did before we started”.  I don’t think it is just ESMAC-SIAMC that suffers in this way. I see it at most of the conferences I attend and in a lot of papers that I read (and, if I’m being honest, in some of the papers that I write).

Just two areas illustrate this. One is in the advanced and complex modelling that is so often the focus of contemporary biomechanics. We learnt (or had confirmed) in Rome that the results are highly dependent on the details of how the individual anatomy is parameterised and of the calibration processes used to define joint centres.  The overall conclusion is that we are less confident in the output of our simulations and models after we’ve performed this research than we were before. Of course it is important to know what the limitations of our research. At some stage, however, we will have to acknowledge those limitations and accept the conclusion that the biological complexity of the human neuromusculoskeletal system is just too great for us to stand any chance of applying these techniques usefully (at least not beyond the constraints of healthy people exercising tightly controlled tasks).

The other field is that of measuring spasticity. Seven or eight years ago I was really excited about the prospect of instrumenting clinical tests to quantify spasticity more rigorously. The results I’ve seen reported are really quite disappointing in that it seems that spasticity is a rather complex and badly behaved phenomenon that simply refuses to be measured.  I have little faith any longer that spasticity is a purely velocity dependent response  (Lance, 1980) and the additional complexity that is introduced when displacement, acceleration or even jerk might have to be considered removes any hope that we will ever understand how these components interrelate within the current paradigm.

One of the “advantages” of research leaving us less clear of what is happening than we were before is that it opens up the conclusion that “further research is required to better understand these phenomena”. Research thus begets research and the university departments rub their hands in glee at the prospect of more research grants, papers and citations. For many of us it leads to increased job security. We have a vicious circle that delights and thrives in creating complexity and chaos.

This is particularly bizarre in orthopaedic and rehabilitation fields (and perhaps more widely across health sciences) in that the tools we have to treat our patients are generally extremely blunt. Selective dorsal rhizotomy, intrathecal baclofen and botulinum toxin are the only tools we have to manage spasticity. At a clinical level the only decision we need to make is which, if any, of these to use. If we want our research to be clinically useful we need to concentrate on the simple questions that need to be answered before we turn our focus to the more complicated ones that don’t.

The small number of presentations that did impress me posed a research question in such a way that the answer actually improved my understanding of a given issue. Almost all of these resulted in me having a clearer, simpler view of the world after the presentation. This doesn’t necessarily require simplistic techniques. The walk-DMC scale that Kat Steele and Mike Schwartz proposed in their prize winning paper (page 25 of Abstract Book) uses a sophisticated technique. It is a technique, however, that has been appropriately selected to answer a well posed research question (Can we quantify the effect of disordered motor control on walking in children with cerebral palsy?). Once the appropriate techniques has been selected the answer is simple (Yes, at least on the basis of the preliminary analysis they presented).

One of the most ancient tests of the scientific quality is Occam’s Razor, that science (and our thinking in general) should be as simple possible but no simpler. It would be interesting to perform an audit of the presentations at any contemporary conference against this criterion. I suspect the results would be quite sobering.


Lance, J. (1980). Pathophysiology of spasticity and clinical experience with baclofen. In R. Feldman, R. Young & W. Koella (Eds.), Spasticity: disordered motor control (pp. 485-495). Chicago: Year book medical publishers.



  1. Hi Richard,
    I agree with you that this years’ ESMAC-SIAMOC meeting left me asking more questions than feeling satisfied with what we have already achieved, but unlike you, this also left me rather energized. This not only because, as you pointed out, increased complexity provides us with job security (important to a young researcher :), but because it is exactly this that defines science: the uncovering of layers on the path to finding solutions. What you refer to as uncertainty is actually an opening up of information, previously unmeasured and uncovered. Take your example on spasticity. Exactly by instrumenting the clinical spasticity tests were we able to demonstrate that spasticity is not only velocity-dependent. This shows that the underlying assumptions we had previously made were incorrect and supports the necessity to improve our assessments. This finding also opens up pathways to explain the variability in spasticity treatment response and will help us rethink our management strategies. So rather than this complexity ‘removing hope’ of understanding the paradigm, I think it will actually help us to make sense of it. In that way, we’ll actually be closer to Occam’s Razor, with fewer assumptions, and more accurate science.

  2. Hi Richard,

    Your honest but rather pessimistic comment of the last ESMAC-SIAMOC meeting triggered me. I don’t share that feeling with you, and I tried to explain why.

    First, I fully agree with Lynn. This will surely not surprise you. I also have some additional thoughts.

    I first would also add a reply on your statement ‘Selective dorsal rhizotomy, intrathecal baclofen and botulinum toxin are the only tools we have to manage spasticity. At a clinical level the only decision we need to make is which, if any, of these to use.’

    I believe that exactly one of the problems of treatment is that clinicians frequently only think about that simple question, whether you should treat the patient or not. However, in order to figure this out, the next question is much more crucial: ‘HOW should we treat the patients with selective dorsal rhizotomy (SDR), intrathecal baclofen pump (ITB) and botulinum toxin (BTX)?’. With the improved instrumented assessments of spasticity and with gait analysis we can fine tune the treatment, meaning that we can indicate which muscles should be targeted, and to what extend, in each of these procedures. The problem arises with treatments that are applied in a too simple way, just by deciding whether to treat or not, as packages, without reflection and careful analysis and decomposition of the problem. I agree that this is a complex puzzle, unfortunately. But I am not that pessimistic, because quite some pieces of this puzzle have been studied in a proper way , thereby step by step increasing our insight into the problem.

    More concretely I can refer to BTX treatment that now can be fine tuned based on detailed instrumented spasticity assessment combined with gait analysis. This provides a profile of the level of neural and non-neural components of hypertonia, and its impact on gait function. This insight cannot be extracted from one or two 10 minutes presentations on a conference, but can result from an integration of these limited conference contributions with previous and ongoing studies.

    I can also refer to the SDR procedure, which should be applied in a very selective way, by taking into account the overall profile of spasticity and weakness, and patient history to make the procedure much more than a purely neuro-surgical act. It surely does not make the problem simple. The decision on the selection of the rootlets and the number of rootlets to be cut can be made on an extended set of objective information, such as spasticity level and type of spasticity, impact on gait and the natural history (taking into account effects of previous treatments). This will make the SDR procedure much more selective. By systematically applying these promising comprehensive evaluations that have been established and validated by several multidisciplinary research teams, especially by applying them on large groups of patients, we can all contribute to further improve the treatment options and get beyond the simple question of whether you simply need to treat the child with SDR, ITB, or BTX, without considering the specific goal with related fine tuning of the treatment.

    Research indeed begets research, but I believe this is not a purely university department issue. Fortunately, much of our research is triggered by clinical problems, aiming at improving treatments for specific patient groups. If we keep our view on these clinical problems, try to assess them as good as possible and try to merge all available knowledge, even if this causes confusion, we do see new pathways that are interesting, not only from a research point of view (ensuring our job security), but especially from a clinical point of view (improving treatment). This process is much slower that we would like it to be, but it is not stagnating. After working in this clinical field of pathological motion for about 20 years I am happy to see several crucial progresses in clinical research that dramatically changed our treatment policies, and I expect lots of new evolutions in the near future, especially due improved assessments step by step resulting in new insights in muscle behavior on a short-term and long-term perspective.

    I would like to make another comment as well. Some of the separate presentations might indeed be considered as disappointing and confusing when looking at it in an isolated way. This is a comon problem of every conference. However, in view of all recent studies and progress in the field, such small studies might be considered in a very different way. These small studies, even inconclusive or confusing, encourage us to reflect about established treatment paradigms and ensure progress in the field. They also encourage to merge research fields. One example is the progress on instrumented spasticity and weakness assessment and the progress on the assessment of muscle structure and mechanical properties, both during stationary assessment and during gait. Although this surely causes confusion, especially when generally accepted hypotheses are not confirmed, it highlights new promising pathways, which might give us the courage to reconsider and change our treatment strategies.

    So I would encourage to use conferences such as ESMAC-SIAMOC to reflect and integrate all the small pieces of knowledge, encourage all members of multidisciplinary teams to make progress in proper assessments and exchange knowledge, even if it is only a small piece of knowledge that does not seem to add much from a first point of view. And especially I believe we should never give up to improve our assessments of the problems in the most accurate and comprehensive way when we find new aspects which were unexpected and confusing. Apart from consolidating job security in sciences, it provides step by step more insight into these very complex problems such as muscle behavior in different pathologies.


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