The Chicken or The Egg in Youth Fitness

[wpfblike] Youth Fitness: which came first?

youth fitness


Mobility before Stability?


Stability before Mobility?


I’ve read research that states both…


In your practical experience, which order makes most sense in youth fitness?


Please… Let us know:


– the IYCA Team


P.S. Perhaps the Answer You’re Looking For Is Right Here —> https://iyca.org/fitspecialist1


27 Responses

  1. Kamal says:

    If Mobility cannot be expressed from a stable position, then stability be increased and mobility introduce.

    If Stability is lacking at a given range of motion, due to altered length tension relationship, then the reverese will be true?

    But i see few mobility issues, it’s common to see stability issues, and being unstable it’s difficult to express total mobility, or desired range.

  2. Peter Camann says:

    After spending last weekend with Gray Cook and Lee Burton, PhD, at PB!’s FMS 2-day seminar, I know what they’d say, and I know you know both these bright individuals as colleagues. Having said that, Brian, mobility comes before stability. All one has to do is observe babies in a crib. Mobility comes first. Stability has to be learned and earned.

  3. Peter Camann says:

    PS Good question, Brian. : )

  4. Cory says:

    Agreed. I like to think I can look at Cook, Burton etc. with a critical eye though one’s first inclination is to take everything they say as gospel. I look at it critically through practical application–so not only do the theories/principles make sense but they also work in the real world with real clients.

  5. Brian Grasso says:

    For the record, Peter, I could not agree with you more. Chalk this up as one of the reasons I can’t stand fitness machines for kids. Stability IS an earned characteristic, and is done so naturally with mobility as part of the dual equation. Reducing or eliminating the natural stabilizing forces that occur while we produce movement, ESPECIALLY when the organism is young, learning and impressionable, to me, is entirely counterproductive to establishing natural function. BG.

  6. Aaron says:

    I was leaning towards mobility, but when I read Peter’s comment that sealed the deal. if kids can’t move, they will never learn how to control movement because they are never “stretching” and pushing their abilities.

    “Reducing or eliminating the natural stabilizing forces that occur while we produce movement, ESPECIALLY when the organism is young, learning and impressionable, to me, is entirely counterproductive to establishing natural function.”

    Thanks for the question Brian.

  7. Casey Wheel says:

    I love the FMS theory of mobility before stability. Looking at new borns, they can all suck on their toes, then they gain the stability to pick their head up, crawl, stand, and walk.

    However stability could come before mobility when it comes to performing an exercise. Your body needs to stabilize first then go through the motions. The easiest comparison is lift weights, because you feel yourself get tight or brace, the push, pull, squat, deadlift, etc etc. We do the same when playing sports or doing an activity but I believe its at an unconscious level. But if you don’t have the proper mobility, that’s when stabilizing during exercise can lead to compensations and injuries.

  8. Paul says:

    Brian, would you be kind enough to cite specific empirical scientific studies which demonstrate that strength training on a machine results in a reduced capacity to stabilize joints? Thanks.

  9. Ray Rice says:

    In my opinion, the two work hand in hand. The infant observation is great example. Looking closer at the observation, the child is also working stability to achieve better movement/mobility. Bigger issues can be developed when they discover poor habits that gives them mobility. The infant has a desire to get somewhere. When the infant makes his/her moves they are in the discovery mode. Whatever they find that works (good or bad) and it gets them to the next step, it becomes their way of movement until something better is discivered. Then the next question is: They had to move a body part first? But, in order to move a body part, the muscles had to be somewhat stable. This can go on forever and ever. Bottom line, mobility and stability are inseparable.

  10. Darren says:

    I think the stability vs mobility debate is short-sighted. Mobility simply means to be mobile. Mobile implies the ability to move efficiently/effectively. You cannot do that without some stability somewhere at some time. Too much mobility is a problem, and too much stability can be a problem as well, the balance between the two is totally unique to the individual.

    The best movement drills are the ones that require an athlete/individual to stabilize something while creating quality movement elsewhere.

    The FMS deep squat progression (not the assessment itself necessarily) is a perfect example, being able to stabilize the hips in the low squat position while creating movement through the T-Spine and shoulder. This solidifies the bottom up theory of development and works on mobility and stability simultaneously. There are other examples seen in walking, running, dead-lifting, squatting, jumping, cycling, etc…

    This is how the body is constantly working, so I always try to remind myself that any stability or mobility drills we’re working on should tie into something larger requiring both stability and mobility at the same time. PNF patterns like the chop and lift are a few of my favourites in this realm.

  11. I dont think this question is the same as the chicken or the egg. Train mobility at the hip and stability at the low back at the same time. Get the rib cage to move properly and watch the shoulder gain stability. In short, the two go hand in hand.


  12. Well I believe mobility and stability work together. I have a 2 year old daughter and watching her development has been truly amazing. She naturally figured out mobility and stability at the same time. For example, the best way she figured to stand up from a supine position on her back to standing was incredible! First, she would sit up like Dracula rising out of his coffin using her core only! (no hands!) Then, she would bend her knees and tuck her feet under hips. Finally, she would rock her body forward into a squat position and proceed to stand. That takes an incredible amount of mobility, stability, and strength! She will be 3 soon and to this day she stills moves that way! What do you say to that?

  13. Les Young says:

    Both mobility and stability at some point cannot be separted, with that being said I look at my kids they are able to be mobile before that can demonstrate stability, however, at the advance stages of exercise there must be stability inorder to perform a desired mobile exercise. In conclusion it depends at what level of exercise we are discussing.

  14. Perry Aitchison says:

    Stability, in essence, is the ability to resist outside forces that would, without stability, result in movement. Stability cannot exist without the tendency toward movement. Athletes with good stability are able to manipulate movement better than those with poor stability, but clearly movement begins the cycle.

  15. Dr. Kwame M. Brown says:

    FACT: From a developmental perspective, the mobility happens first, just like Peter and Brian stated.

    FACT: If you have a young person come to you later in life, the question may be reversed. Stability will allow increased mobility. The CNS will restrict movement if it senses a lack of stability.

    Some misinterpret this to think that the stiffer someone is, the better. It is the ability of the brain to make the CHOICE BETWEEN stability and mobility, and have either available at a given moment, that is key. This is why any program worth it’s salt has both present, all over the body, and in different situations on differing terrain.

  16. Paul says:

    This is an absolutely fascinating thread. I only wish there were some scientific evidence presented…anywhere.

    If it’s a fact that mobility arises in advance of stability, as stated by Peter, Brian, and Dr. Brown, then the implication is that the system is inherently unstable.

    If the CNS restricts motor outflow, as a result of sensing inherent instability, then mobility will be inhibited, from the outset. In other words, children will never develop the capacity to move. This isn’t making too much sense.

    Ok, is there any evidence for any of this? At what point does the CNS begin to develop stability? Again, any evidence?

    This is such an extraordinarily complex issue, yet it’s being reduced to a few convenient bytes.

    Why not begin with a defintion of stability, distinguishing between joint stability and total body stability (ie stability of the C.O.G.) and then proceed from there? Because each definition has a host of conditions which need to be managed, not all of which lead to clinical manifestations.

  17. Dr. Kwame M. Brown says:


    Good to have you back. To start, I think you are being a tad to literal and “all or nothing” here when you say:

    “If the CNS restricts motor outflow, as a result of sensing inherent instability, then mobility will be inhibited, from the outset. In other words, children will never develop the capacity to move. This isn’t making too much sense.”

    Obviously, there is middle ground between freedom and fluidity of movement / full command and complete paralysis. Middle ground between Stephen Hawking and Roger Federer.

    For scientific evidence of mobility arising before stability: Try to get a baby to sit upright. They do not yet have the ability. They are “floppy”. But they certainly have the ability to move limbs in all kinds of interesting directions. What would you attribute this to besides mobility without the ability to restrict degrees of freedom where necessary? The evidence on this is long standing and clear from centuries of observation of babies. We don’t need a controlled study here.

    You can see stability begin to develop as children crawl, then sit up on their own, walk. You then see stability take a front seat to mobility when toddlers exhibit en bloc movement, where the CNS will restrict degrees of freedom to “strap” the head to the torso functionally. Tweens / Teens, especially during the peak growth spurt, are well documented to sometimes have hypermobility of joints and lack of limb control, most probably due to the quickened growth of the limbs. This is evidenced in textbooks on child motor development, and has been for decades.

    From my perspective, this is a lot like asking for scientific research on whether children are smaller than adults. These are things that are known.

    With respect to your question about what is being talked about here (what type of stability), I would posit that we are really discussing the ability of the nervous system to restrict or unrestrict degrees of freedom. This really is an action exerted on the musculature, with information from the joints and muscles.

    The question at hand, from my perspective, is the ability to CHOOSE mobility and stability. I don’t necessarily mean choosing from a frontal cerebral origin (although sometimes that too), but more from the lower centers in the brain on a moment to moment basis. With many physical limitations that arise with development, overpractice, and/or lack of practice (all can have effect simultaneously or in succession), the ability to restrict or unrestrict the degrees of freedom can be hampered. It is regulation that is at the core (no pun intended) of this debate.

    It is in the INTERVENTION where the research needs to be done, not in identifying the features of the problem. We need research identifying best practices. This is of course difficult to do with IRB issues and control / caveat issues.

  18. Paul says:

    Dr. Brown,

    Thank you for your comments. I actually wasn’t being literal, just repeating what was said in the discussion. Perhaps my simple way of thinking failed to grasp your point.

    I think we’re now onto something very interesting; the notion of restricting, or put another way, marshalling appropriate degrees of freedom.

    But is this necessarily a stability issue?

    Nicolai Bernstein devoted his life’s work to managing degrees of freedom, and in his model, coordination arises from reducing them, and simplifying movement patterns.

    Carlo DeLuca resolves this through his notion of common drive, which is to say that the management of degrees of freedom comes from the elimination of unnecessary motor activity, not the introduction of extraneous activity.

    Perhaps, what appears to be a lack of stability is actually the outcome of excessive motor activity, leading to a loss of movement control. Parkinson’s tremors, for example, don’t arise because of joint instability, do they?

    Maybe you’re suggesting the same thing, but I think the context of stability is misleading. Consider bi-phasic or tri-phasic EMG patterns. These antagonistic firing patterns are evidence of the system’s desire to maintain joint stability throughout movement. In fact, Moshe Solomonow has demonstrated, quite effectively, that antagonist activity increases linearly with joint velocity. In other words, as the joint increases its rate of acceleration, antagonist activity increases in order to maintain balanced forces around the joint – hence, joint stability. This falls neatly in line with Emilio Bizzi’s equilibrium point hypothesis, in which the system strives to find balanced loading around the joints, and in fact, determines movement end-points based on levels of intramuscular equilibration.

    No one, however, has shown that this occurs only at later points of maturation, so I’m inclined to think that this capability is available at birth, but is honed through maturation. I would think that we’d see, very clearly, tri-phasic patterns evident even in very young children. So the capacity to stabilize is present, but what is absent, is the ability to control (not regulate) motor outflow.

    Thus, instead of assuming that one is unstable, we might simply practice the skill at hand, seeking movement efficiency, and let the rest take care of itself.

    My request for definition, is really one of clarity. Stability may be defined as we’ve discussed; that the system seeks balanced forces around the joint during movement. Or, we can define stability as the need to restrict movement altogether, which is established through joint stiffness. In this, the system engages in high degrees of muscular co-contraction, resulting in an isometric state. But this is a wholly different interpretation of joint stability, and would certainly be ineffective if one’s goal were to apply force to external objects.

    This is why I suggest that the topic is far too complicated to simply be relegated to “which would you develop first?”

  19. Brian Grasso says:

    Great stuff, guys! Paul, in a given training program for a high school athlete, would you perform mobilizing type exercises (ankle/hip mobs) prior to your held contraction work (bridges, planks) or vice-versa? Why? Thanks.

  20. Dr. Kwame M. Brown says:


    I think I can respond here in a way that can be effective and constructive.

    “But is this necessarily a stability issue?”

    Here, we are getting into Bill Clinton territory (it depends on what your definition of “is” is). Just kidding! I think what we are really discussing here is the ability to alternatively, and as needed situationally, restrict or release degrees of freedom. Yes, this is absolutely a neuro-physical issue, as is everything the human body does. The neural part doesn’t just include base level “motor” control, but also emotion, self concept.

    Let’s look at the tennis forehand. The most effective way to hit the shot involves keeping the legs “solid” (restricting some degrees of freedom), winding the torso and hips (storing potential energy here and in the legs), and releasing the arm and torso with the stored potential energy driving it. In other words, the shot is storage, then release. Of course, this is not a complete release of degrees of freedom in the arm, because the ball would sail. There is a metered, patterned, sequenced release of certain degrees of freedom in each joint. There is an interplay between “release” and “restrict”. In those players that don’t have a lot of control over the torso and legs, they will lose power because of this loss of potential energy. This also has the theoretical potential to result in greater injury, as does anything the human body does that is not fluid from the feet upward. There will likely be compensations here because the athlete still desires the same result. This underscores the importance of the young playing with movement in a variety of situations from a variety of angles and encountered resistances.

    This segmental restrict / release is what I believe most people are discussing here when they are talking about stability vs. mobility, not the inherent properties at the joint (though that influences this process as well).

    Therefore, the capacity to “stabilize” in this sense IS proven to develop later, since it involves motor control. In fact, with the exception of the passive properties of structure and tissue, there is no aspect of stability that does not involve a neural input / output / integration scenario.

    It is for this reason that babies, children, adolescents and the untrained (or more accurately, the unplayed) at any age are more likely to be unable to achieve the necessary balance in the restrict / release equation. This in turn results in unstable body segments during movement.

    Paul says: “This is why I suggest that the topic is far too complicated to simply be relegated to ‘which would you develop first?'”

    Certainly, I don’t think we can make sweeping statements about which we develop first in a training session with the “average” kid. There is no average kid.

    But from a practitioner’s perspective, we MUST start somewhere, no? I think that you look at the general characteristics of the group / individual, and gauge what appears to be the issue.

    Problems restricting?
    Problems releasing?

    Experiment over time. This is the value of the long view, and the long term approach. There is less guess work in the long run. A 6 week treat ’em and street ’em program requires guessing.

    We’re talking about Play, over long period of time, where the young are experimenting with different movements and paradigms involving restricting and releasing different parts of the body in relationship to one another.

    This, over time, will render all things in balance. But some thought still has to be given to “weighting” different activities.

    A practical example:

    With that growth spurt adolescent, I have seen that while the issue may be control, if the young person “feels” tight, some mobility exercises may be effective to begin with to make them comfortable to learn. We forget the value of this often.

    The controlled study you ask for, looking for bi and triphasic activity at end ROM, would be an interesting one.

    Good luck getting IRB approval for indwelling / surface electrodes and voluntary scripted movement patterns in babies / toddlers, LOL! As someone who is involved in the field of child development, I can tell you I hope that it doesn’t get approved.

    Some things are just known well enough through observation. Babies don’t control movement well. They learn to through trial and error as they develop. That’s just fact. When they don’t get enough experience, or too much of a certain narrow experience, the ability is blunted. It is up to us to “open” our young charges to edifying movement experiences that help them improve their abilities. Some of this, from the practitioner’s perspective, will involve trial and error right along with them. The more information we get from each subject, the closer we can get to a conclusion.

    But start with the general clues we have begun to outline here. Be a keen observer.

  21. Paul says:

    Hi Brian,

    I don’t really do either of those things. In fact, I think that approach has become far too formulated.

    My principle focus is on power development, not necessarily right from the beginning, but ultimately that’s what I’m trying to achieve. When the neuromuscular system has the capacity to generate power, then everything else that we’ve been chatting about resolves itself.

    I’m also a critical observer of motion, and look for insufficient, extraneous, and superfluous motion when people are exercising. If I see something, my first question is why are they doing that, and how can I measure what I see? my next question is how can I validate what I just measured?

    After I have construct validity, then I attend to the specific needs of the system, and I’ll use whatever means I can to achieve it.

    That’s it, pretty simple.

  22. Paul says:

    Dr. Brown,

    I truly love these exchanges, but frankly, I think they’re getting a bit verbose.

    My perspective on your post is that what you’re describing is the development of skill. I’ll leave it at that.

    As I said, this is an extremely complex subject, more suitable to a weekend symposium than a string of blog comments. Maybe that’s something to consider.

    As for IRBs, you may have a point, but I am a research scientist as well as a practitioner, and I always look for validation of methods and practices. We can claim that it’s next to impossible to acquire data, and that may be true. But the fact still remains, that without valid data, we will still be guessing and expressing unsubstantiated opinions, no matter how much common sense we apply.

    I learned a long time ago that the human system is far too complex, far too sophisticated, and far too unpredictable to think that our opinions, however logically developed, can predict its behavior. Thus, I don’t operate off of opinions. If someone makes a statement, then I’ll ask for evidence. If there is none, then they should create it, or say that there isn’t any, but it shouldn’t be presented as fact. I think that does everyone a diservice.

  23. Dr. Kwame M. Brown says:

    @Dr. Juris:

    Doctors would never be able to treat patients without opinion, based on synthesizing knowledge.

    It’s not just common sense here (at least from my perspective), it is about educated guesses based on diffuse knowledge being synthesized.

    So, your solution for practitioners that work with kids every day is: In the absence of hard empirical evidence that gives an exact answer, do nothing? Teach nothing?

    Let’s not forget that this blog is from the perspective of the practitioner who has to make those decisions to the best of his/her knowledge given theories that stem from and are synthesized from what we DO know.

    I agree that things shouldn’t be presented as fact that aren’t. Babies can’t control their bodies well and aren’t good at regulating degrees of freedom. This is a fact. This ability develops through experience and developmental plan. Another fact.

    Our only option is to make educated guesses based on several bodies of knowledge that exist.

    My friend, it seems that you are a very literal, linear thinker, and that is understood as well as valued. But taking that too far means paralysis by analysis. We have to make safe bets based on synthesis of knowledge, until we can do better.

    For example, we have a body of evidence that supports play based programming for children based on some observations of children + knowledge of primate / rodent brains and effects of play. But we certainly have not measured pruning in toddler brains, have we? Therefore, we are operating off of opinion. So, should the practitioner then not program play for children because they don’t have any direct mechanistic evidence of what it is doing? No, we go with our best guesses until more information reveals itself.

  24. Paul says:

    Dr. Brown,

    Those are fair arguments. Doctors, however, would never make decisions based on opinions alone. They evaluate the evidence that is presented to them before rendering a diagnosis.

    But let’s evaluate this from a different perspective. Brian, for example, made a comment earlier in this string that fitness machines are counterproductive to developing stability.

    Now, if I really were a literal and linear thinker, as you suggest, I would take that statement at face value as being factual. Is it a fact?

    Unless Brian can produce some evidence that machines actually have that effect, then he is merely stating an opinion, and he should present it that way. It doesn’t mean that he is wrong or right, but that the answer is unknown. That has more value to me than the opinion itself.

    A similar issue arose in an earlier blog in which we discussed treadmill function. You had a guest blogger write that hip extension on the treadmill was passive. That information was presented as fact, despite copious research studies that refute his position, and demonstrate that hip extension on a treadmill is active, requiring the same forces as over ground running. Incidentally, his comments were never corrected or retracted, thus, the myth was perpetuated.

    I am not advocating establishing practices that only utilize scientific evidence, and omit anything else. To the contrary, I think it’s important to use corollary information and sometimes intuition. But knowing whether the information that I have to work with is derived from fact or opinion, helps me to make better decisions.

    Parenthetically, as infant motor development goes, the evolution of movement and skill that you have described have actually been well documented by people like Joseph Higgins, Karl Newell, and Ronald Angel. If I have observation-based documented evidence of the effects of play-based activities in children, then I indeed, have evidence. Likewise, research examining primate brains may not transfer exactly to human brains, but I think we can both agree that there are enough similarities in the neuro-physiology to draw meaningful conclusions from the available evidence.

    But back to the point; those who depend on forums like this for information that shapes their thinking, ought to be properly informed when something has a factual scientific basis, or when it is unsubstantiated opinion. That way, they are more empowered to use the information in an intelligent manner. Returning to your doctor analogy, if my doctor resorted only to guessing, then he wouldn’t be my doctor for very long.

    The problem with the sports fitness industry, as I see it, is the vast majority of decisions are based on opinions and conjecture, and are rarely supported by any evidence at all.

    Why don’t we try and meet in the middle?

  25. Dr. Kwame M. Brown says:

    Points well taken and agreed.

    My question remains though:

    How do we address the observed lack of the ability to maintain motionlessness / stability / restriction in one segment versus movement of another, connected segment.

    Not knowing empirically whether this problem is an issue of sequencing, structure, physical micro-growth of the nervous system, or pure activation / recruitment level, we still have to make that training decision on the fly.

    What is your suggestion to answer the original question to the best of our ability having the information we have?

    What would we address first with, for lack of a more descriptive term, the “floppy” youngster?

    As I see it right now, it is mainly trial and error over a long period of time to gain clues. Seeing the effects of interventions of skill practice, play exploration, systemic / segmental strength, etc. and documenting these effects on the overall pattern.

    Having also in the mix the conundrum that the system is developing as well, would this make the decision impossible in your view?

  26. Dr. Kwame M. Brown says:

    So my question to you: Which things that I said above aren’t supported by facts / research?

  27. Paul says:

    Dr. Brown,

    Sorry for the delay, too many things going on around me.

    “So my question to you: Which things that I said above aren’t supported by facts / research?”

    So many things have been stated, that I’m not sure which posting you’re referencing. Also, please keep in mind, that while most of this discussion occurs between the two of us, I am often responding to comments and posts from other contributors. So, I’ll defer on the last question.

    Regarding the 9/23 post, I think you raise a very interesting question, but it’s one that I would not necessarily relate to “stability.”

    This is why I’ve asked for better definitions of stability. One could assess control of the center of gravity over the base of support, one could address joint laxity or integrity, or one could examine the balance of joint torques through a range of motion. I think respondents in this string have addressed all of these in different ways. Some of which, lack evidentiary support. But I’ll drop that issue for the moment.

    From your description, however, I would assign the topic to joint acceleration, both positive and negative. If you give that some thought, you might agree that the task requirements, as you’ve detailed them, are founded on the ability to accelerate and decelerate various joints, based on the nature of the skill.

    Acceleration is a power issue. When youngsters should begin a power development program, however, depends upon a great number of factors, from age and gender, to skill level, physical, mental, and emotional maturity, predisposition to injury, or any existing injuries, etc. The list goes on.

    Play is important for overall maturation, skill enhancement, and emotional support. But there is ample evidence that simple basic strength training can lay a foundation for structural stabilty, strength, and performance.

    Then, the trial and error, or intuitive coaching strategies, can engage in order to determine when power is introduced.

    As I stated in an earlier post, I think this is an extraordinarily complex issue. Why don’t you consider a symposium, or webinar series? I think a complete education in this area would be of great benefit to your subscribers.


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