Letter to the Editor - Controlling Resistance Training Variables in Interventions for Chronic Nonspecific Low Back Pain

Spine have just published online a letter I submitted to the Editor regarding a recent publication by Willemink et al. which I discussed on this blog earlier in the year.

If anyone would like a copy please contact me.

The letter highlights my concerns with the authors conclusions in light of the methodology employed and follows on to a degree from the letter I wrote in response to Steiger et al. last year in European Spine Journal.

The main issues refer to the poor control of resistance training variables, in particular the intensity of effort, load and also frequency.

In their paper Willemink et al suggest that adaptations on the multifidus musculature are not related in any way to clinical improvement i.e. pain and disability. However another issue with their methodology relates to the lack of control group. Their training protocol was likely insufficient to induce muscular adaptation anyway, but it is also not possible to rule out that the clinical improvements may have been due to placebo type effects.

I think it is premature to suggest that changes in muscular morphology or performance are unrelated to clinical improvements at present. Especially when our own research utilising very specific isolated lumbar extension exercise has just reported that improvements in isolated lumbar extension strength are in fact significantly related to clinical improvements.

There's No Such Thing as Cardio - Full Length Video

Last summer, just after official publication of a review article I and several co-authors worked very hard on, I gave a talk at The 21 Convention in London whereby I explained the concept in the paper to the attendees.

Anthony has now released the full video, free to the world.

On the whole I'm pleased with how the presentation went and think it conveys the concepts discussed in the paper in an easy to understand manner.

As always please watch and offer any feedback either on the youtube channel, The 21 Convention website using my email on the right.

Oh and make sure you download the full talk (or any others, particularly Doug McGuff's, Skyler Tanner's, Eric Daniels and Yaron Brook's which so far from last years conferences I have enjoyed immensely) and in doing so help support Anthony's efforts with The 21 Convention.

A Randomised Controlled Trial of Limited Range of Motion Lumbar Extension Exercise in Chronic Low Back Pain

Earlier in the year I shared the poster I presented reporting on the results of the first empirical piece of research from my PhD study.  

Well the full study has now been published in Spine.

The abstract is below, if anyone wants a copy of the full text just feel free to drop me an email!

A Randomised Controlled Trial of Limited Range of Motion Lumbar Extension Exercise in Chronic Low Back Pain

Abstract

Study Design. Randomized controlled trial.

Objective. To compare the effects of full range of motion (ROM) and limited ROM isolated lumbar extension exercise upon fullROM lumbar extension strength, ROM, perceived pain and disability.

Summary of Background Data. Limited ROM is common in chronic low back pain as is lumbar extensor deconditioning. Limited ROM exercise is a common prescription but is yet to be empirically tested.

Methods. Male (n = 21) and females (n = 17) with non-specific CLBP were initially recruited. Participants were randomised to either a full ROM (FullROM) or limited ROM (LimROM) training group, or a control group. Twenty four participants (males n = 14, females n = 10) completed the study and were included in analysis. The intervention lasted 12 weeks. FullROM and LimROM completed isolated lumbar extension resistance training 1x/week, performing 1x/set of exercise at 80% of their maximal tested functional torque to failure. FullROM group trained through a full ROM. LimROM group trained through the mid 50% of their full ROM.
Full ROM isolated lumbar extension strength, lumbar, and standing ROM (Schobers test), and perceived pain (visual analogue scale) and disability (Revised Oswestry Disability Index) were measured pre and post intervention.

Results: FullROM and Lim ROM significantly improved in full ROM lumbar extension strength, perceived pain and disability compared with the control group. No changes occurred in lumbar or standing ROM. No significant differences were found between either FullROM or LimROM for any outcome measure. Changes in perceived pain and disability met minimal clinically important change values for FullROM (VAS, -30.3+/-25.76mm and ODI, -18.2+/-6.63pts) and LimROM (VAS, -16.29+/-10.97mm and ODI, -12+/-5.16pts).

Conclusions: The results suggest that both FullROM and LimROM are equally effective in increasing full ROM lumbar extension strength and producing clinically meaningful improvement in perceived pain and disability.

For those who decide to take a look at the full text there is a further interesting result reported that is not in the abstract (for lack of space).

Because of the concerns I had with a paper published by Steiger et al. I decided that I would ensure to examine the associations between targeted areas of my intervention (in this case isolated lumbar extension strength) and both pain and disability. Steiger et al. had noted that there was a lack of association between improvements in such outcomes and so the target of many exercise interventions was probably not responsible for the clinical improvements in pain and disability.

The results from my study however have suggested that there is a significant moderate correlation between improvement in isolated lumbar extension strength and both pain (r = -.488 to -.668)  and disability (r = -.414 to -.539) i.e. the greater a participants strength improved the greater their pain/disability decreased. 

Now it is impossible to tell which direction this association goes from just this result. Improved pain might allow the participant to willingly generate more strength. But in the context of deconditioning's cross-sectional and prospective association with LBP and many of its symptoms, I think it is entirely plausible that the greater the improvement in the target of the exercise (isolated lumbar extension strength in this case) the greater the improvement in pain/disability. Add to this that any exercise can cause some improvement in pain, but in non-specific approaches the performance outcomes (i.e. trunk extension) do not correlate with this change, it suggests that just improving pain through cognitive or placebo means to some degree does not allow the participant to improve performance to the same degree.

Considering the other recent study published in Spine that looked to question this concept I am hoping that further discourse will open and more research be done to elucidate the direction of mechanism.

Multiple Joint and Single Joint Exercises - The Big 3/5 is Enough?

Perhaps in terms of upper body strength and hypertrophy development it would seem so.

Effect of adding single-joint exercises to a multi-joint exercise resistance-training program on strength and hypertrophy in untrained subjects

ABSTRACTThe aim of this study was to examine the effect of adding single-joint (SJ) exercises to a multi-joint (MJ) exercise resistance-training program on upper body muscle size and strength. Twenty-nine untrained young men participated in a 10-week training session. They were randomly divided in 2 groups: the MJ group performed only MJ exercises (lat pulldown and bench press); the MJ+SJ group performed the same MJ exercises plus SJ exercises (lat pulldown, bench press, elbow flexion, and elbow extension). Before and after the training period, the muscle thickness (MT) of the elbow flexors was measured with ultrasound, and peak torque (PT) was measured with an isokinetic dynamometer. There was a significant (p < 0.05) increase in MT (6.5% for MJ and 7.04% for MJ+SJ) and PT (10.40% for MJ and 12.85% for MJ+SJ) in both groups, but there were no between-group differences. Therefore, this study showed that the inclusion of SJ exercises in a MJ exercise training program resulted in no additional benefits in terms of muscle size or strength gains in untrained young men.

I can't get access to the full text at the moment (will be able to at some point through the libraries database) but would appreciate it sooner if someone else can get it (email in the sidebar).

It would seem however to provide support, at least for the lat-pulldown and the bench press, that the elbow flexors and extensors are adequately stimulated and conditioned through these movements.

Whether it is reasonable to extrapolate this to other exercises, such as multiple joint lower body movements like the leg press, is unsure. 

From my groups research it certainly seems that isolation is important for lumbar extensor development as both the deadlift and unrestrained extension exercise fail to significantly improve lumbar extension strength.

But at least for upper body development it would seem that additional exercises to address 'weak areas' may be unnecessary. 

Although, perhaps a longer intervention may have found significantly greater gains in the MJ+SJ group? There may be a point of diminishing returns with MJ exercises and that's where SJ exercises can come into play. But this is all necessarily speculative.

In terms of time and efficiency at least it would seem that a pulldown and chest press based movement is all thats needed for optimal development of both elbow flexors and extensors.

Ancestral Health Symposium 2013 - Abstract

I just wanted to put a post up here to note that I have been given the honour of presenting this year at the Ancestral health Symposium alongside many other luminaries in the ancestral health movement. 

The abstract of my 20 minute presentation follows:

Title: An ancient perspective on deconditioning in low back pain.

Bio: James Steele BSc (Hons), Ph.D. Cand., is an Associate Lecturer at Southampton Solent University (United Kingdom). He has previously published peer reviewed articles on the area of resistance training. His current research, however, seeks to examine low back pain (LBP) as a multifactorial condition from an exercise physiology/biomechanics perspective. In particular he is examining the effects of specifically addressing lumbar extensor deconditioning in LBP with isolated lumbar extension resistance exercise, upon other associated physical symptoms of chronic LBP. 

Abstract: LBP is a multifactorial issue with many associated symptoms and potential causes. Prevalence is high in westernised populations and also comparably high in rural and indigenous populations. Other diseases common in western populations, such as obesity, diabetes, heart disease, and cancer are almost absent in populations devoid of the western influence and who follow a traditional diet and lifestyle. It therefore seems counter-intuitive that LBP rates should also be high in traditional populations. The hypothesis that an evolutionarily determined factor might predispose these high rates across a wide range of Homo sapiens populations thus seems plausible to examine. Fossil data from the clade Anthropoidea suggest adaptations in predominant habitual locomotion styles from 1) arboreal quadruped, to 2) semi-terrestrial quadruped, to 3) biped over the past ~20 million years. These adaptations were accompanied and permitted by important anatomical evolutionary changes occurring in the lumbar spine and pelvis. These changes appear to have developed from 1) a long mobile lumbar vertebral column, laterally facing pelvis and large lumbar extensors to 2) a short lumbar vertebral column, posterior location of the transverse process, lengthening of the ilia, reduction of extensor musculature and increase in passive rigidity through entrapment and invagination and 3) to re-lengthening of the vertebral column, reduction in length and broadening of the ilia and sacrum. However, comparative musculature anatomy between old world monkeys and modern humans suggests the presence of a relatively smaller lumbar extensor musculature, and thus potentially weaker, in humans. In addition, hip/trunk extensor musculature of short backed primates is well developed. Anatomically modern humans therefore may bear the compromise of relatively strong hip/trunk extensors and relatively weak lumbar extensors in combination with a long flexible lumbar spine. This may contribute to disuse atrophy of the lumbar extensors which may explain the consistent association of their deconditioning in LBP, and also predispose modern humans to the high prevalence of LBP presently observed.

Learning Objectives:

Upon completion of this session, participants will be able,

1. Describe the prevalence of LBP across a range of populations.

2. Explain the role the lumbar extensor musculature plays in LBP and its multifactorial symptoms, and some of the key observations regarding this musculature.

3. Understand the hypothesis that anatomical evolutionary changes might be responsible for deconditioning of the lumbar extensor musculature and thus the high prevalence of LBP across a range of populations. 

4. Recognise predictions of this hypothesis and suggested methods of testing them.

For those of you who have been wondering what ever happened to the next parts in my series of blog posts from way back covering this topic, well, I continued researching and putting the evidence together in preparation for this and for writing a paper on the topic. So AHS13 will see me present my full ideas on this topic alongside some proposals for future research to tests the predictions that stem from them.

I'm really looking forward to heading out to Atlanta and getting to meet with the people who's work I have been reading for some time now, and getting to be a part of what is a fascinating direction in research that has prompted and shaped many of my thought in my own research.

Hope to see you all there!

Medico-Mechanical Gymnastics - Some Things Haven't Changed

When Arthur Jones set out to produce MedX equipment it was with the goal of producing the ability to provide objective measurements of spinal function, and to also allow objective understanding of exercise performance during rehabilitation. In fact, this has essentially been the goal with any and all spinal testing devices that do not involve hands on manipulation such as that commonly used by Physiotherapists. 

When I was working on my Undergraduate dissertation this was something I paid attention to in my literature review and I attempted to point out some of the problems with manual based techniques applied by the therapist for both testing and training.

In this case I paid attention to the literature specifically looking at McKenzie techniques but the prinicples are applicable to all 'hands on' manual techniques.

I've copied and pasted that section of my dissertation here for perusal (I'm not going to go through and hyper-link all the references though). I do so however to lead into an exert that I enjoyed whilst reading through an old book on Gustav Zanders Medico-Mechanical Gymnastics given to me at xmas suggesting that this is an argument that has been around for a long time.

The most widely used form of rehabilitation through spinal manipulation therapy are McKenzie techniques. These techniques are utilised by physiotherapists (Battie et al. 1994; Foster et al. 1999; Hurly et al. 2000). The Mckenzie technique involves first an assessment of the patient using a ‘cause and effect’ relationship. This requires the therapist to provide systematic progression of applied mechanical forces to utilise a pain response in order to monitor changes in function. The treatment then involves an education of the patient to actively manage their condition and if necessary then the therapist can apply ‘hands on techniques’ until the patient can manage the prescribed skills on their own (McKenzie Institute International, 2009). There is much contradicting evidence towards to the efficacy of spinal manipulation and McKenzie techniques in the treatment of CLBP (NHS Centre for Reviews and Dissemination, 2000). A Meta-analysis of thirty nine randomised controlled trials evaluating spinal manipulative therapy concluded that it had no statistically significant advantage over general practitioner care, analgesics, physical therapy, exercises, or back schools (Assendelft et al. 2004). Measurement of pain used a 100 mm point visual analogue scale and found that only when compared to sham therapy was there a significant difference by 10 mm (95% CI, 2 – 17). This was only concluded for acute pain.  Two other reviews of McKenzie therapies effectiveness made similar conclusions as to its effectiveness in the short term. Clare et al. (2004) found a reduction in short term pain of 8.6 (95% CI, 3.5 – 13.7) on the 100 point analogue scale. Busanich & Verscheure (2006) found similar results. Both reviews conclude that McKenzie therapy is effective in the short term on outcomes such as pain and disability however there is insufficient data on its effect over the long term. Despite themselves reporting contradictory evidence for the efficacy of spinal manipulation, recent guidelines offer its recommendation for up to a period of 12 weeks (National Institute for Health and Clinical Excellence, 2009). The contradictory evidence ranged from one study finding a small to moderate difference, to the majority finding no significant difference between manipulation and others treatments. These came from a range of studies varying in quality and bias (National Institute for Health and Clinical Excellence, 2009). The McKenzie Institute International (2009) provides reference to numerous studies and published guidelines concerning the efficacy of the approach. They too provide contradictory evidence. The following are reviews cited by McKenzie Institute International that offer contradictory recommendations on McKenzie therapy as a treatment and diagnostic tool:-

·        ‘McKenzie method is recommended as a classification based treatment system and some of the relevant evidence presented (American College of Occupation and Environmental Medicine, 2005)’

·        ‘This wide ranging review and guideline includes a summary of the McKenzie approach, both as a treatment and as a diagnostic method. They concluded there was limited evidence to support its use as a treatment for both acute and chronic back pain, and moderate evidence indicating its value as a diagnostic tool and prognostic indicator (Danish Institute for Health Technology Assessment, 1999)’

·        ‘These guidelines have been developed using a structured and rigorous methodology. For sub-acute and chronic back pain they recommend that there is good evidence to include certain specific exercises, including the McKenzie method  (Philadelphia Panel, 2001)’

·        ‘Development of a clinical management model for back pain patients from previously published guidelines and systematic reviews. McKenzie approach was listed as a recommended therapeutic intervention for acute and for chronic back pain with ‘poor’ scientific evidence; and for sub-acute back pain with ‘moderate’ scientific evidence (Poitras et al. 2008)’

·        ‘McKenzie recommended for acute and chronic back pain. Guidelines noted the reliability of assessment with trained therapists; the value of sub-grouping using centralisation; and the ability of McKenzie method to improve pain and disability in the short-term. This was supported by best levels of evidence: systematic reviews and RCTs (Work Loss Data Institute, 2008)’ (McKenzie Institute International, 2009) Along with the copious amounts of contradictory evidence for spinal manipulation therapy there are numerous problems with its use as a treatment and diagnostic tool. Most studies have used pain or disability as an outcome measure, where disability is regarded as quality of life. Although a valuable outcome measure it is not an objectively measureable one. Return to normal function is the only truly objective outcome measure of any rehabilitation program and in order to measure this we must be able to objectively measure change in function (Fulton, 1993). Because of its reliance upon manual and ‘hands on’ procedures it is impossible to provide any objective measure of function or to provide an objective, systematic progression in treatment. In its essence manual therapy is based upon the subjective feeling of the therapist as to how much pressure, resistance or velocity they are providing during manipulation. Based upon the contradictory evidence for its efficacy when compared to other   treatments and on the problems associated with its measurement capabilities it would seem that manual therapy only provides short term relief from pain but is not a suitable means of providing longer term progressive treatments. As a diagnostic tool it is also flawed due to its subjective nature and may cause more discomfort for the patient because its ‘cause and effect’, force/pain relationship may require a great deal of trial and error from the therapist.

Bare in mind I wrote this a few years ago now and honestly I think pain is probably the most important outcome from a treatment program certainly from the patients perspective.

But after reading that now enjoy and consider this exert from the book "G. Zander's Medico-Mechanical Gymnastics: Its Method, Importance, and Application."

"It is easy to understand that it was very hard work to give movements on the Ling system. 'How can you stand giving such a number of movements?' a patient one day asked the gymnast into whose hands he had entrusted himself. 'I cannot stand it' was the reply. And so it was, for after some time his health was irretrievably lost. This case shows sufficiently the dark side of manual gymnastics. It is true that forced work of this kind may not always bring on injurious consequences for the movement-giver, but the weariness that a skilled and popular gymnast must feel after treating one patient after another for many hours, will surely have a more or less disadvantageous influence on the treatment of the patient. This fact is expressed by a write in a foreign periodical in the following manner: 'The gymnast is mistaken, if he thinks that his weariness is the effect of increase of strength in the patient, or that occasional development of strength in himself corresponds to a passing weakness in the patient. Whatever may be the advantages of the manual method in some respects, it is difficult to deny the truth of these words; for besides the inevitable weariness of the gymnast after several hours work, he is also subjected to occaisional influences which diminish his strength, and consequently the intensity of the movement cannot always be the same.'

All Pain Starts as Acute Pain

There is a pervasive meme with regards to LBP that 

"80% of all low back injuries and acute LBP recovers within ~6-12 weeks"

This is often a rod in the support of psychosocial models of explaining why we have such high prevalence of CLBP. If the majority of acute LBP heals itself spontaneously in ~6-12 weeks then the high prevalence of reported CLBP must be down to psychosocial factors, right? Only a minority of LBP must be due to actual physical injury or factors stemming from physical characteristics because if the majority heals quickly but people keep on reporting pain they must not actually be injured, right?

The thing is the meme above is "wronger than a very wrong thing", to quote Blackadder. In fact, the majority of low back injuries and acute LBP continue and develop into chronic LBP (1, 2) often with increasing frequency and severity (3, 4). 

Now, it could be argued that this development of a vast majority of acute LBP into CLBP is down to pain sensitisation stemming from the original occurrence and underlying pain generating mechanism, or down to psychosocial 'yellow flags' that might predict development of chronicity and disablement, or more likely a combination of the both contributing as causative and exerting influence on one another also.

But an important point to make is that the psychosocial factors often blamed for CLBP are likely not responsible for the initiation of the series of event in the first place - the initial injury or episode of LBP. Pyschosocial factors may contribute to it becoming a chronic condition, or they might arise from the chronic presence of pain - this is not 100% clear as yet. But something which I have taken issue with regarding much of the trend towards considering CLBP as a predominantly psychosocial condition is that the model never really offers an answer for what causes LBP in the first place - right at the beginning, what causes the injury, the acute pain? 

This is a key point, and something I rarely see mentioned explicitly in the literature, so I was surprised and pleased when reading a recent paper by Michael Adams and colleagues (5) to see this so explicitly stated.

"Psychosocial factors have little influence on the initiation of severe back pain (Adams et al., 1999), and chronic back pain always starts as acute back pain. The originator of the Biopsychosocial Model of back pain has since warned that physical causes of back pain should not be neglected (Waddell, 2002)."

Figuring out what results in such high low back injury occurrence is a really interesting thing to consider. The psychosocial model seems to imply that freak severe injury must account for all incidences of low back injury and acute LBP because it already assumes that physical factors or dysfunctions are a result of pain, not the cause (6). Yet it seems that accidents such as slips or falls, despite resulting in higher cost injuries, are very uncommon with regard to cause of injury; lifting or materials handling, however, are most commonly considered a cause (7). 

What I think the most interesting thing to look at is what renders our back so susceptible to injuries in the first place? Essentially what factor predisposes us or increases our risk to succumbing to the variety of potential injury mechanisms in the first place? 

I have my ideas on what is likely the most influencing factor, but I still think we've a way to go before any definitive conclusions that be given, and its very likely that a variety of factors interplay in this area.