Updated: Jan 4, 2020
Mobility, and the training for this, has enjoyed an explosion in popularity. Rightly or wrongly it has now become an ‘industry’ in its own right. This blog will explore the ‘mysterious science’ of mobility and try to find where the truth lies.
Mobility is booming, just ask google.
What contributes to this rise in popularity would be pure conjecture, but this particular gentleman might have something to do with it.
Or even this particular form of training:
As a strength and conditioning coach, I’ve seen mobility become a mainstay of programming; once again rightly or wrongly it now takes up a large proportion of athlete’s and patient’s time. I would like to ensure the moralising of this issue is not what you take away from this blog - simply that it is a ‘novel’ training practice and like anything new, we need to critically appraise its effectiveness and determine its overall utility in the health landscape. So if mobility training is here to stay (as it most likely is) and if coaches, physiotherapists and all manner of other health care providers (HCPs) continue to program this modality without restraint, it would be good to provide some guidance around what it is and when it might be of use.
Once again, this blog is not about whether or not mobility is inherently good or bad (I actually think that’s a contrived question - as you’ll see throughout - the answer is moreso along the lines of ‘it depends’); but with anything that is both new, lucrative and opening up a whole host of ‘instant experts’, questions have to be asked. First and most pressing, do we even know what ‘it’ is? I contend that regardless of claims of scientifically based systems backed by decades of research - see here - we really don’t know what’s going on and we haven’t even really properly defined what mobility actually is.
Mobility is best described as the athlete’s ability to reach the intended range in a specific skill; it is a weight bearing and multi-joint concept (Ref). Mobility, therefore, is highly dependent on stability and coordination of multiple joints. It can subsequently confusingly be associated with coordinated movement and is espoused to precede a highly-developed locomotor apparatus; a strategy of preventing accidents from happening (Ref). This confusing ‘catch-all’ term has led to a wide discrepancy in what is currently termed mobility training. There needs to be a concerted effort to properly define the term mobility, or more specific usage of terminology within the athletic performance literature, as currently it can be used to describe many forms of training and practices.
Adding to the confusion
It seems that, intermittently, the term mobility is used interchangeably with the term motor control, or at least used in the sense to imply that mobility may be an earlier stage to developing motor control (Ref). These terms may be depicting similar concepts along the same continuum, and a solution may be to use the term ‘early motor control’ instead of ‘mobility’ to avoid confusion. It is also confusingly used sometimes when referring to simple range of motion (Ref), but it typically doesn’t get confused with flexibility, which is more concretely defined as absolute range of motion possible within a joint or series of joints and may be either static or dynamic; however, both of these concepts may contribute to our overall ‘idea’ of what mobility is. If you’re confused, good, because I am too.
What do we know
Does it help with performance?
Besides many systems claiming superiority in this space, there is an incredible paucity of research in this area. Part of this may be the inherent difficulty we have in defining where ‘mobility training’ begins and where other stuff ends. Secomb et al demonstrated in a cohort of 16 Australian surfers that improved mobility may be the basis of improved landing performance (Ref). This study admits, however, that increased muscle strength is a confounder for the findings (Ref).
To my knowledge there have been no long-term trials on the effectiveness on mobility training on performance in comparison to programs without mobility training included. We simply don’t know what it actually does, and therefore how much time to spend on it or how much value to place on it in the grand scheme of performance.
Does it help with injury risk?
There are countless studies analysing the predictive ability of range of motion on injury risk. By no means a comprehensive assessment of these, but it may be apt to say that despite continual looking, conclusive evidence that reduced range can predict injury continues to elude those that look for it. Reduced knee extension range has no bearing on hamstring injury risk in a relatively robust meta-analysis here. It seems range of motion is pretty useless as a risk factor for most lower extremity injuries (Ref). Now, this is probably because injuries are far more complex than one or two factors alone and our predictive algorithms need to evolve far beyond their current state to be able to meaningfully approach the problem. This is also because it really does depend on the type of sport or action that you are involved in as to whether range of motion becomes any kind of risk factor worth considering. Notable here is that in activities like gymnastics reduced flexibility, specific to hips may be worth considering as predictive of injury, but it is surprising how small the list of sports is where a lack of flexibility is truly predictive of injury (Ref). Joint laxity is a different construct, so I will not comment on this. The phrase, ‘it depends,’ applies here and will come up again.
We have to remember where the practice of mobility really became ‘vogue’ - a sport whose main modality is improving body mechanics to make olympic lifting more efficient (Crossfit).
It makes sense
A counter argument may be that, this is just common sense; why do we need the research? If you have more range of motion available, under control, during skills it should serve for the basis of better skills. This increased range under control is also potentially going to lead to less ‘compensation’ and thus potentially less injury. This makes sense, it does, and in all likelihood it’s probably how it works. But the fact of the matter is that we don’t really know.
All of this is not to say range of motion isn’t important, but simply stating it may not be as important as we consider it to be. Which may demonstrate further that more systematic approaches are needed to define, and homogenise the terminology involved in mobility before any kind of interventional trial can determine any effectiveness.
OK, so what do we do with it?
Like most things, judicious use should permeate how we approach it. It may depend on the goal in mind. It should not be a surprise that loaded, eccentric training has been shown to be effective in improving range of motion in this systematic review by Kieran O’Sullivan. This might be some of what mobility training does, but again, the entire definition becomes confusing when you take in all of what mobility training has to offer. Some forms of mobility are just a waste of time.
One issue with mobility training is that it isn’t applied judiciously and there are narratives in the health landscape that simply don’t help people - read this article here and tell me if you think that ‘mobility’ isn’t a term yielded with malicous intent. As I have stated above, mobility training has not been shown to be correlated with, predictive of, or effective on performance and it has unclear links in injury. Linking mobility with pain is something that is commonly done; this - if you understand the true nature of pain - is probably a mistake. The unfortunate situation that we find ourselves in, is that the practice of mobility really took off by its biggest proponents espousing (thus far non-existent) causal relationships between mobility and pain. Just see the title of Kelly Starrett’s breakout book:
Given the above review of the (lack of) literature into the area, then it’s easy to see these claims are spurious. On this note, I can empathise with those of you who are affronted by this - I was too until I began to think a little differently. The problems with claims like this mean that it will lead lots of people into a ‘false hope’ of simply ‘mobilising’ their pain away; once again, if you begin to understand the nature of pain, it becomes apparent that this can be unhelpful. It may reduce some of your athletes or patient’s pain, but just because they mobilised and subsequently found a relief in pain doesn’t mean the mobilisation was the active ingredient - it may play a part - but it simply can’t explain the entire outcome. This situation should be better interpreted as your athletes did a thing (mobilisation) and they got a response (pain reduction); there are a whole host of things happening here, mobilising tissues is but one of them - it doesn’t mean the pain was in the tissues, not in the short term or the long term.
Placing value on mobility training is, therefore, inherently based on the coaches or HCPs wants and needs. It is not a fix-all for pain, nor has it been proven to improve performance, or even reduce injuries. There are some common claims that continue to present in the realm of mobility, which I will use to summarise the value we should place on mobility training.
“Everyone should squat like a baby”
Unequivocally not true, because well, babies are babies and adults are adults. Adults will never be babies, not ever. We have different anatomy, different physical properties, different mechanics, different neurological systems; we’re just.. different. Conversely and going to the other end of the spectrum:
“Everyone should squat differently”
Probably more appropriate, but it doesn’t mean that we let ‘form’ go out the window. Squatting form is an important prerequisite to performing the skill. There are far too many blogs on squatting for me to attempt to add to the noise, so this can probably be summarised by thinking of skills like squatting as having a framework with important individual differences. Common sense, right?
Nick Tumminello probably said this best when he said, “Squat like an adult - Squat like YOU!” Although the statement, “by trying to ‘fix’ adults into the same movement standard, might have the opposite effect and ‘cause’ problems” (paraphrased) is probably not correct - we don’t have any evidence that mobility training will cause injury or pain - but certainly the sentiment of wasting time doing this training with limited pay-off is an important one.
So in conclusion, it really depends on how much time you want to provide mobility. Understanding that, for now, we have really limited evidence to show any effectiveness on performance, any effect on injury and it certainly does not stop pain from happening. The coach or HCP needs to weigh up how much time to devote to this form of training against other forms - namely loading appropriately. We need to define what we are doing with mobility training, we need to perform this training judiciously just like any other training stimulus and we definitely need to stop telling people that they can mobilise their pain away.