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If you have been any where near social media over the last few years it cannot have escaped your attention that pain is seen as a much more complicated entity than had been previously thought.

We have to see pain as a SUBJECTIVE experience that can be modified by many varying elements such as emotional, sensory and cognitive factors. One of the most studied aspects of the modulation of the pain experience is the placebo and the placebo effect.

Here is a great comment on what the study of the placebo effect is.

“The study of the placebo effect, at its core, is the study of how the context of beliefs and values shape brain processes related to perception and emotion and, ultimately, mental and physical health” - Benedetti *HERE*

Multiple factors

We could perhaps split any therapeutic interaction into two components:

• Specific/active biological
• Contextual/psychosocial

I think it is fair to say the Specific/active biological part is probably thought about much more than the Contextual/psychosocial part, certainly during my educational process.

External contextual factors

External contextual factors such as visual stimulus, smells, size and colour of tablets have all been shown to exert an effect on the sensation of pain. Here we see a noxious stimulus when associated with the colour red as being perceived as hotter and hurting more than when associated with the colour blue *HERE*

Internal contextual factors

Internal contextual factors such as previous experiences, beliefs and expectations and positive or negative emotion have also been shown to modulate the outcome of a treatment.

So it sounds like this placebo and its effects thing should be pretty important right? Yep but unfortunately one of my least favourite words is…… Placebo!

Here are a couple of definitions of what a placebo is.

"a substance or procedure... that is objectively without specific activity for the condition being treated" - Shapiro

“An intervention designed to simulate a medical therapy that at the time of use is believed not to be a specific therapy for the condition for which it is offered” - Brody

We are presented with a paradox here. If something is without specific activity or is inert then how can it have an effect? This paradox presents a problem as it casts the placebo and its effect in a negative light.

Here are some words that have been associated with placebo and the placebo effect.

• Deception.
• Ineffective.
• Unethical.
• Fake
• Unintended

Here is a great paper from the main man on the subject, Fabrizio Benedetti “Mechanisms of Placebo and Placebo-Related Effects Across Diseases and Treatments” who explains it all much better than me!

A much better term

A much better term in my opinion is CONTEXT.

Regardless of what you do with the human body from being a trainer to a physio or even a doctor, it is important to recognise that the CONTEXT you create in your interaction with your clients and patients has a very real effect on the outcome you are trying to achieve. We could even go as far as saying that being a good car salesman has similarities in this regard.

Now we could see this as unethical if someone were to manipulate CONTEXT to create a positive effect whilst knowing that the intervention they were using had NO real evidence of effect. But if we can SPECIFICALLY create the most advantageous context coupled with best practice then surely this has to be the overriding goal? This is suggested here with regards to manual therapy *HERE*   

Potentially EVEN more important could be that a negative context could influence a well evidenced treatment and reduce its effect. The influence of negative context appears to be more powerful than the influence of a positive context *HERE*

Simply avoiding creating a negative context could be a big deal for the overall outcome. A classic paper from Darlow *HERE* highlights the impact of what is said on the attitudes and beliefs of patients with lower back pain. It has been suggested that the variable of a negative context or nocebo is scarcely considered in a clinical setting. In fact peoples satisfaction is not influenced only by the treatment outcome but also but interaction with the therapist and the PROCESS of care itself. The magic is not just in the technique as many believe! *HERE*

Think about the negative influence of potentially NORMAL scan results. This may not only create a short-term negative influence but can go on to change behaviours and expected outcomes over the longer term. This study found early imaging for acute back pain actually increased long term disability *HERE* . A potential reason maybe the negative contexts that MRI’s can create. Simply rewording MRI reports had a positive effect on aspects associated with creating a positive context *HERE*

The complicated bit

A lot of study into placebo and the placebo effect has focused on the neuroanatomical and biological aspects such as the brain areas involved and chemicals produced. This is exceptionally important in my opinion as it provides a clear link between thoughts and emotions and chemical influences on the experience of pain. Rather than being a mysterious enigmatic creation of the mind, positive context becomes a real event with real chemical mechanisms.

Top down modulatory systems are activated in both positive and negative context. This excellent paper explores these mechanisms. “Different contexts, Different pains and different experiences”

Positive context activates key neurotransmitters such as:

• Endogenous Opioid
• Cannabinoids
• Dopamine
• Oxytocin

These are are all involved in analgesia.

Negative context activates

• Cholecystokinin (anti opioid)
• Opiod/dopamine deactivation
• Cyclooxygenase-prostaglandins (pro inflammatory) pathway

Brain areas such as:

• Anterior cingulate cortex,
• Amygdala,
• Dorsolateral prefrontal cortex
• Periaqueductal gray
• Rostral ventromedial Medulla
• Hypothalamus

Are all involved in the placebo effect.

There are some fantastic papers on the descending inhibitory systems. I would advise anyone with an interest in pain to read these.

Descending Inhibitory Systems

Central modulation of pain

What we can learn by looking at context and its effect on these modulatory systems is that the effects are VERY REAL and backed up by a large body of scientific literature. Hence the context we create should be a very real consideration rather than a side effect or something to be hoped for from an ineffective treatment.

Reward analgesia

Pain that is coupled with a positive context via reward is another example of pain modulation. The coupling of positive context of reward has been shown to significantly increase pain tolerance through the activation of the opioid and cannabinoid systems.

This experiment *HERE* used ischemically induced pain and we can potentially apply this to the old fitness saying ‘Feel the burn’ that ties an uncomfortable sensation into a positive context to drive us on to achieve exercise targets.

Dopamine is also linked with reward analgesia and involves the Nucleus accumbens (NAc) that pumps out the neurotransmitter dopamine. Both cocaine and opiates (there is a rumour they make you feel good!) stimulate dopamine release from the NAc.

Conditioning effect

We also have an effect of preconditioning and associative learning. If we have previously had a good experience from a treatment we are more likely to have another good experience with the same treatment EVEN if the treatment potentially is ineffective or implausible.

We may associate a person with a specific outcome such as “My therapist has magic hands”, this belief and expectation goes some way to making a positive outcome more likely to happen again. Expectation of decreased pain was looked *HERE* 

Previous experiences shape our future expectations and when the expectations are met they reinforce future belief leading to an even greater relationship. We could potentially apply this model of belief expectation and conditioning to repeated treatments that give people short-term relief.

Predicted expectation and outcomes of treatment have been shown to have a relationship for a number of conditions.

This is a great paper from Bialosky.
“Individual Expectation: An Overlooked, but Pertinent, Factor in the Treatment of Individuals Experiencing Musculoskeletal Pain” 

Pain facilitation

We have to also remember that pain perception can be facilitated or ‘turned up’ as well. The rostral ventromedial medulla (RVM) has both ‘off’ (inhibitory) and ‘on’ cells (facilitatory) that will influence pain perception. The two papers linked above on descending modulatory mechanisms go into this process in more detail.

During periods of acute injury this may provide a powerful biological protective mechanism but may also be involved in the maintenance of chronic pain.

The title of this paper is fantastic, “Bad news from the brain”  It describes mechanisms of descending facilitation linked into cognitive and emotional aspects.

The critical bit

My only caveat is the literature is still dominated by the concept of nociception and I would be interested to understand the effects of context on less nociceptively driven pain mechanisms too, especially in light of our changing understanding of pain! Does this model work better with chronic pain driven by sensitization of the periphery, spinal cord and brain stem driving nociception (from potentially previously non nociceptive stimulus) rather than supra spinally?

The simple bit

CREATE A POSITIVE CONTEXT!

Make people feel positive about you, themselves, the issue they have, the process they are about to go through and the outcome of it all!

Start by listening and actually hearing. We are ALL guilty of formulating a reply in our heads while someone is still talking. This probably means you are not listening! Listening and concentrating is a real skill in my opinion and one I am constantly struggling with.

Helping reconceptualise someone’s current experience and the meaning of what they are experiencing might just get some of these complicated neurobiological systems going.

The practical bit - Ways in which we can affect context

This recent paper “Enhance placebo, avoid nocebo: How contextual factors affect physiotherapy outcomes” explores ways of creating the best context during a therapeutic encounter.

Communication is a key aspect to providing a positive context and being “person centered”

These are some key communication points from the paper:

• Be optimistic during the consultation and regarding the dysfunction
•  Explore the patient's disease and illness, request and trust the patient's opinion
•  Encourage questions, answer queries from the patient, deliver positive feedback
• Investigate expectation, preferences and the patient's previous experiences
•  Be warm, confident, friendly, relaxed and open during the clinical encounter
•  Use verbal expressions of empathy, support, sympathy and language reciprocity
•  Use positive messages associated with treatment for pain relief;
•  Use eye contact, smiling, caring expressions of support and interest
•  Use affirmative head nodding, forward leaning and open body posture

This was another interesting recent paper that provided a self assessment tool for dealing with patients in healthcare “Dealing with patients in healthcare: A self-assessment tool” 

Example bit

My bias is using movement as a tool to help.

The question I ask myself is “How can I create a positive context around moving?”

This means that I can hopefully get the positive physical biological and the contextual biological parts of an interaction.

We may have to overcome negative context surrounding the physical aspect first to actually get to the physical aspect! We can often pathologise movement that may create entirely the opposite effect regardless of someone’s positive intentions.

• Avoid negative language around moving or a movement and use positive language and examples
• Explain simply, including basic science, why moving may help
• Listen to any fears someone has around moving or a specific movement (predicted outcome)
• What movements/type of moving does someone enjoy?
• Ask what a specific negative outcome might be and discuss this.
• Shared decision making in how far (ROM), how heavy, how long (duration), how fast?
• Set small achievable targets that provide reward
• Reinforce positive outcomes and reinforce any violation of negative expected outcomes through discussion
• Discuss any potential side effects such as muscle soreness and what this may mean.

Anyone who has read my blog will know that the concept of movement variability fits my biases very nicely. But as time goes by and I delve deeper and deeper into the subject I find myself being forced to challenge those biases as the information does not always fall as nicely into place as I once hoped it would!

‘Movement variability’ seems to have become a bit of a buzzword like ‘functional’ and ‘neuroplasticity’ before it.

Both those terms have merit when applied with the right dose of science and context but have had their validity eroded by poorly reasoned blanket usage. We end up with ‘XXX works because of…..variability’ which is simply a sentence not a mechanism or explanation.

What NOT to do!

Where the concept of movement variability has been most enlightening is to help us learn what NOT to do, not always a reason TO DO something. We see the same with pain science that helps us understand what NOT to say not always what to say. Research into core stability has helped us to understand the probabilities are stacked against it being the answer to back pain but in many cases not what the actual answer is.

Understanding that movement is variable helps us to recognize that models that define ‘good’ and ‘bad’ movement are perhaps less valid than we previously thought. We have proposed models of ‘optimal’ movement that blame any deviation for micro trauma when in fact biological adaptation to tolerable dosages is much more likely to occur.

When we look at movement data for asymptomatic people we see a huge variation in the way that they move. So different people move differently and have different ways of achieving the same task and then the same individual may also have multiple ways of achieving that same task. So movement has both inter and intra individual variation.

This means that deviations from an ‘optimal’ (within safe anatomical range) ARE NOT problems just variations or resource for problem solving. We always have to consider the potential harm of labeling movements as ‘dangerous’ or having the potential to damage and how that affects someone’s desire to move for fear of injury or re injury and even if this information has ‘truth’ to it!

End point vs Coordinative

There are a couple of ways we can look at movement variability and increase our understanding.

The traditional view of variability would be to analyse the ‘end point’ or the execution of a skill, an example would be a throwing action or a stride when running. We would want to keep the amount of variability fairly stable here as to much variability would make it hard to execute a skill repetitively, so just doing random stuff and justifying it by calling it variable does not really fit the bill here but enough variability around a general movement template is good! In more reactive functions we may see the need for greater inter and intra movement variability.

Another way to look at variability is ‘coordinative variability’. This is looking at the inter limb relationship during the action or how the 'end point' is physically organized between the functional muscle & joint linkages that comprise the human movement system. The knee and hip coupling in running would be an example of this, the stride may look no different externally but the internal couplings maybe organized subtly differently temporaly each time. Much of the research into variability has looked at coordinative variability.

Skilled movers often display reasonably low ‘end point’ variability or skill execution, higher for reactive scenario’s than rehearsed, with higher ‘coordinative variability’ potentially to decrease repetitive loads which could help avoid overuse type injury and fits nicely with Bernstein’s great quote of “repetition without repetition”

So is movement variability an important concept to apply practically?

As always the answer comes down to “it depends”.

Movement is variable and being able to move in variable ways and having the ability to so is no bad thing, especially the more you require this bio motor ability for sport or health. If you already have a lot then it is probably not such a big deal. If you don’t have a lot then it likely becomes more of a big deal. We must be careful to not confuse variations around relevant movements with just moving in as many random ways as possible.

Perhaps where I have changed my view point most is the idea that pain ALWAYS = reduced variability. It is likely to be a little bit more complex than that. Sometimes we see the two factors correlate and other times not so much. Pain and motor patterns are both outputs of a complex system that may work independently or interdependently.

Here is a cool quote from "Neural representations and the cortical body matrix: implications for sports medicine and future directions"

“Pain and motor control are outputs of primary neurotags, intimately linked but not hierarchically differentiated”

We also have to separate acute from chronic pain states here as during a painful episode it has been postulated that the motor system is searching for non painful ways to move and therefore may become more variable find pain free solutions. A chronic problem maybe characterised by maladaptive protective stiffness with the net result being reduced variability. We need to carefully interpret who is being studied and the nature of their pain when using the information from these studies.

This paper maybe an example of this "Coupling angle variability in healthy and patellofemoral pain runners" where we see an increase in variability correlated with an increase in pain. A uniform response in variability, that would make thing sooo much simpler, is also not observed which given what we know about humans is unsurprising.

Movement variability likely to be very important for those that have their variability reduced after a painful episode but we cannot say with certainty that this will be everybody and that pain has a consistent effect on variability. But for those that DO have their variability reduced it may play a role in the transition to chronicity as previously discussed by Moseley and Hodges.

 “In summary, the findings show that when pain induces a loss of normal variability in the postural strategy, then normal strategy does not return, which is important because non resolution of the strategy probably increases the likelihood of further back trouble” Mosely and hodges

We have to be aware that motor system adaptations, we are learning, are highly individual and certainly not stereotypical as we may have been led to believe by many ‘models’ of movement and movement ‘dysfunction’. It has been postulated by some that having higher variability in movement maybe protective against the development of chronic pain complaints.

How do we use this information clinically or for training?

That is a great question and one with no clear answer. The vast majority have no access to expensive lab equipment such as 3D video analysis that would allow them to objectively collect the kind of data to answer this question. My opinion is that we can apply movement challenges or tasks that require variability in position, range, speed, balance etc that may highlight the adaptability of someone to variable stimuli.

We could define a problem of posture in a similar way. Applying movement challenges to ascertain if someone can move away from their postural start position may help decide if the posture is actually an issue or not.

We could do this to specific areas of the body or within relevant tasks that are problematic or you feel are relevant generally or relevant functionally. As we have so many relevant tasks and ways to achieve them it is hard to have objective data to work with for such a vast array of movements and their variations.

The question is do we need objective data here?

It is always preferable but probably unrealistic for most clinicians or trainers & coaches.

Perhaps we need a process that fosters inherent variability within the system and focuses more on the task and its constraints rather than solutions to a task such as an inflexible template to adhere to as we see with most exercises. Instead helping people to explore multiple solutions via experimentation with movement patterns and also developing coordinative segmental relationships.

Non linear pedagogy fits the bill nicely here. It moves away from providing a criteria or template led approach that allows the emergence of self organization and inherent variability to occur via the constraints imposed on the task.

You can read more here Chow (2013)

Task constraints could be:

Environment – The space around us.

Instructions – External or internal cues that provide variability

Equipment – Different objects will provide alternative stimulus

An example for a LBP sufferer.

Relevant Task – Bending over to pick something up.

Environment – Placing objects in differing positions to pick up requiring larger or smaller movements or movements in different planes or combination of planes.

Instructions – Sit bum back, bend or straighten the knees or reach left or right to vary the way in which the task is performed.

Equipment – A Power bag would provide the need for an alternative strategy than a barbell as an example. A more functionally relevant everyday item that is problematic could also be used.

Just as variability is probably not THE answer, neither I suspect is the current trend of ‘just load it’. Putting aside the complex multi dimensional nature of many problems, when it comes to a physical stimulus why do we have to choose only one of these concepts?

We may just need two exercises but that provide DIFFERENT stimulus, one that provides a variable movement stimulus, and one that provides a load based stimulus for strength and load tolerance adaptations.

Give exercises with different aims instead of a number of exercises that provide a similar stimulus such as the classic printed therapist sheet!

There has always been this big divide between those that prefer a strength oriented approach to training and rehab and those that like to use a more movement (also called proprioceptive or motor control training) based approach.

For some reason human beings tend to gravitate into camps, tribes or teams, its just part of nature! Training and rehab seems to be no different.

So....which tribe do you belong to?

I could not help but think of the Frankie goes to Hollywood classic!

https://vimeo.com/126022671

First thing we have to realise is that is very hard to completely divorce the two modalities.

Strength training does not mean that we have no proprioceptive input or motor pattern output. Any movement will create feed forward commands and feed back through the proprioceptive system up into the cortex. We may REDUCE the amount of feedback that  comes from differing joint positions and variability of movement during strength training as the movement is often constrained by the increased load. We must remember however proprioception is also about force regulation and a fair amount of proprioceptive research is based on measures involving force rather than being just joint position based.

Equally ‘movement’ training can involve strength and joint loads generated by acceleration & deceleration, end range tension and joint stabilization. Less utilised joint angles may also need less added load to achieve an overload effect that would stimulate a need to increase strength. ‘Strength’ training is essentially adding load to any movement after all, although often specific ‘strength’ exercises are preferred.

We seem to be looking for a one type of training or rehab that encompasses everything. Both types of will individually increase capacity AND interact in relevant situations so need to be looked at concurrently as well.

Maybe it would be better to see strength and movement training as having mostly DIFFERING affects on humans. There will of course be crossover where strength affects movement and movement will affect strength but expecting movement training to increase strength and load tolerance in the same way strength training does maybe misguided. The same is true of strength training, why would it have a specific effect on a motor pattern in the same way practicing that motor pattern would?

The problem here is that this thought process does not fit the ‘tribe’ mentality.

I see this as being similar to the pain science debate and the criticism of the pendulum swinging to far from peripheral to central mechanisms (another tribal debate). Often the truth lies in the middle ground and being inclusive and aware of the impact of many types of rehab and training modalities.

So are strength and movement unrelated?

Now this does not mean that strength and movement are unrelated. This study *Here* (thanks to Nick Clark) found that quadriceps strength was significantly correlated with the function of the knee during walking gait after ACL reconstruction. This makes sense if the level of strength falls below that required for normal movement and this is likely to occur after a significant event such as an ACL injury. One caveat would be that kinematics and strength levels might both be related to pain levels and once pain subsides ‘normal’ motor behavior and strength levels may be restored rather than strength and movement being related to each other.

The relationship between strength and movement patterns after injury is less clear in running potentially because strength levels during or post injury do not fall enough to significantly impact on movement.

This paper *Here* looked at changes in knee biomechanics after a strength training program for the hip abductors in runners with Patellofemoral pain. Peak ‘genu valgum’ or increased hip add and the resulting knee valgus has been hypothesized to be associated (although still unclear!) with PFP. Although hip strengthening programs are designed to decrease peak hip add (and knee abd) this study found a strength training program DID increase strength and decrease pain but did NOT impact on the movement of the knee in terms of peak genu valgum (peak knee valgus) angle at post test compared to baseline. A caveat here is that the analysis of the knee was in 2D, looking at the hip adduction and shank abduction angles, and movement of the knee during running is 3 dimensional.

This study *Here* into the frontal plane kinematics of the knee in running, this time in healthy female subjects, looked at the relationship between hip abduction strength and hip adduction kinematics and found no relationship and this time they did use 3D analysis.

Another study *Here* found that a hip strengthening program did not alter running mechanics in a healthy female population. In fact ‘movement’ training in the form of a single leg squat did not alter running mechanics either but did have an effect on the single leg squat! So ‘movement’ training also displays a healthy relationship with the SAID principle (specific adaptation to imposed demand) and if you want to alter a specific movement you probably have to work on that specific movement.

Gait retraining, the SAID principle in action, is becoming more popular with running *Here* and seems to be effective in improving running kinematics and pain and function in the short term and we also see a crossover to less complex skills such as squatting. It seems running may have more to do with coordination and timing of muscular contraction within a motor pattern  rather than the strength of contraction that can be generated.

So another question is does the complexity of a skill, such as running gait which is very complex, seem to play a part in whether strength training has an impact on movement?

Potentially!

This paper *Here* looked at different training programs to improve knee alignment during landing that has been associated with both ACL and PFP injuries of the knee. They had two groups, a strength group and a jump landing training group and looked at the functional tasks of the single leg squat, single leg landing and bilateral landing.

They found that a strength training program DID affect frontal plane projection angle (FPPA) during a single leg squat AND single leg landing but NOT during a bilateral drop jump as well as increasing strength. Of course the jump landing training group DID improve landing but did NOT improve strength.

The caveat here would be that the strength training program included a single leg squat which more than likely (IMO) creates some motor learning carryover to the FPPA in the single leg test and this was fully acknowledged by the authors.

It might also be that a simpler movement is affected more by changes in strength.

The authors also pointed out that a change in the single leg landing task also improved in the strength group even though they did not train this movement. The conclusion being therefore strength was a factor in the improvement of the FPPA. However we may also see a motor learning carryover between the single leg squat to a single leg landing as they are a reasonably similar movements which has been previously shown. This study also utilised a 2D analysis that has been cited as a limitation in studies that failed to show a link between changes in strength and change in movement.

The authors did come to the most sensible conclusion of incorporating both strength and movement training to decrease FPPA at the knee and also utilised a comprehensive approach to their training programs!

Brain stuff

One argument is that strength training does not affect the movement representations in the cortex but why should we expect them to?

This study *Here*, and yes its not a human study, found that changes in the motor cortex were associated with skill rather than strength as coupled strength and skill training did not induce any more change than skill training alone.

This article *Here* finds that strength training and ‘movement’ training are associated with DIFFERING affects on the brain in terms of neuroplasticity after skill (movement) and strength training.

The strength training group, surprise surprise, increased strength but did not increase the neurophysiological parameters involved with skill training. The skill group improved their skill performance but not their strength. This fits very nicely with the principle of SAID.

Working on different biomotor components created different changes neurologically in terms of MEP (motor evoked potential) behavior at different times throughout the 4 week training program with skill training creating quicker changes than the slower changes associated with strength training.

*Here* we also see different cortical activity between control (movement) and strength tasks.

We may find that strength training is more about the creation of force through co-contraction and movement training is more about the coordination and timing of contraction in relation to a, potentially complex, specific functional skill.

All this does NOT mean increasing strength won’t affect performance or pain

A mistake often made by the ‘movement’ tribe is to reason that because strength does not seem to have a clear relationship with altering movement is that it is not beneficial. Strength, and its more functional relation power, are still bio-motor qualities associated with function and increasing their capacity will surely be beneficial.

This study *Here* found that maximal strength training over 8 weeks improved running economy and  time to exhaustion in distance runners. There maybe a number of mechanisms involved in resistance training affecting distance running performance as seen in this paper. *Here*.

We see a strong correlation *Here* between maximal squat strength and sprint performance in elite soccer players.

If we go back to the article earlier in the piece that looked at strength and knee biomechanics we see that although the strength training program did not affect peak knee kinematics it DID have an effect on PAIN. We would need a control group with knee pain however, instead of just healthies, to allow for the basic healing effects of time to make a really strong link.

Although a causal relationship between decreased strength levels and injury and pain is extremely unclear at the present time, reducing strength inhibition in rehab POST pain is a key variable as we see clearly in the evidence base that pain has an effect on strength output.

This paper *Here* showed that both strength and power (during hop test) were affected in the UNINJURED leg as well after an ACL injury. This may suggest a central modulation of strength and power output after injury not just damage to a joint, muscle or connective tissue.

This systematic review *Here* found that resistance training was beneficial for chronic low back pain, chronic tendinopathy, knee osteoarthritis and post knee surgery potentially strength training being more beneficial for chronic pain. It is important to note the authors felt that high intensity (above 70% 1RM) was more effective than low intensity approaches and did not increase injury risk that seems to be a fear of some when using resistance training.

This study *Here* found that a periodised strength training had a positive influence on strength, pain and disability in active middle to older aged men with chronic back pain.

This paper *Here* looked at the dose response between resistance training and upper and lower back pain in office workers. They found training volume per session more important than the number of sessions attended to be correlated with pain. Interestingly however the specific resistance training group and the more general physical exercise group showed pretty similar reductions in pain.

Strength and movement training were both found to be effective for chronic low back pain in this systematic review compared to controls or other treatments *Here*. It might just be that moving is better than NOT moving for those with chronic lower back pain!

We do have to remember that you could perform an exercise designed to increase strength without ever actually increasing strength because the load, and therefore overload, used does not require an adaptation from the body in terms of strength. A ‘strength’ or ‘strengthening’ exercise on its own is not guaranteed to increase strength. This could be a criticism of papers that look at strength training vs more general programs that the levels of load used are not sufficient to change strength and/or the actual changes in strength are not reported.

We may see that here with a comparison of walking and strength training for chronic lower back pain *Here* with a walking programme as effective as a specific lower back ‘strengthening’ exercises. There were no measures of actual strength or increases in strength in this paper so we do not know if strength is a factor or not and this may fall neatly into what is discussed in the paragraph above.

With CLBP we see an unclear relationship with changes in physical function such as strength and clinical outcome *Here* This does NOT mean that strength training is not beneficial it just means potentially that the moving component may be more important than any increases in strength or other physical factors and the moving component is in the format of strength training.

I have previously discussed this here Strengthening the most overused term in therapy

Some opinion

Certainly putting your body under regular load through resistance training should increase your tolerance to putting your body under load if the loads are sufficient for adaptation!

For example if I am a runner it is very difficult to recreate the loads associated with running without doing MORE running. This may be the cause of a running injury in the first place. However we can manipulate the application of force on the body to elicit cellular mechanotransduction and positive expressions of compounds that alter muscular architecture and subsequent tolerances to load.

Although the loads applied may not be identical in terms of mass X acceleration it does not mean they are not beneficial and the lack of replication and alternative load might be just ‘what the doctor ordered'.

Strength and Injury Prevention

This often cited systematic review *Here* on injury prevention shows very positive effects of strength training on decreasing injuries. This highlights the positive effects of putting your body regularly under load but should not be confused with how strong you are decreasing your injury risk.

You could regularly put your body under load without ever significantly increasing your strength equally you could be pretty strong in comparison to someone else naturally but not put your body under regular load. It is physical activity that is being studied in this paper.

It is also important to note that movement training (proprioceptive) was also shown to have an significant effect on injury prevention and if we think about the body of ACL prevention research we see beneficial effects there.

This all seems nice and clear until we look at this recent paper *Here*  on ACTUAL strength deficits in those that go on to injure their ACLs. Here we see predictive risk factors for isometric hip strength of external rotation being under 20.3% BW (percentage of body weight) or abduction strength under 35.4% BW.

What is unclear here is HOW this impacts on non contact ACL injuries. Although the rationale in this paper is that abnormal lower extremity movement is related to non contact ACL ruptures, lots of evidence on this, and that strength is then related to the abnormal movement. BUT the relationship between strength and movement is most certainly uncertain at the present time in my opinion (and this being my blog my opinion rules!) so as a modifiable risk factor we cannot ignore this data but the exact mechanism is still unclear.

Strength may be more important with relation to movement in those that require very high levels such as in multi planar athletic populations as it might also be important when strength levels do not meet the required level for ‘normal’ movement to occur such as post operatively.

Conclusion

So shock and surprise I hear you gasp, strength and movement training have different effects on human body.

If you want to move in more varied or ‘better’ ways and improve the bits of the body and brain involved with moving then movement training is perfect.

Want to increase strength and power and load tolerance then strength and resistance training is awesome.

Sometimes to be really effective we have to think about using a bit of both and adding load to a relevant movement to get the kind of crossover to ‘function’ that maybe required or desired.

Both will have an impact on different components associated with performance and both should help reduce injuries. We must remember though that performance is extremely hard to quantify as this is often subjective, research often test elements of performance which is quite different.

Probably the clever guys are doing a bit of both already in the fields of rehab and training/performance and realise that both movement and strength training have their part to play.....just on different aspects!