Unstable Silliness Training!
Unstable surface training is common training intervention used in gyms and rehabilitation facilities world wide.
The debate for or against unstable surface training can be a tough one to get into because it has typically been my experience that those who are using these methods don’t really have a good training/rehabilitation methodology or order of exercise progression. There is no real “thinking” involved in the application of these exercises in a training program. Rather, they are just thrown in because they are “hard” and because of this the client “thinks” they are getting more out of it.
Maybe it should be called Unstable Stupidity Training?
Commonly in rehabilitation settings, where most of the research on unstable surface training has been conducted, clinicians will try and advance patients to these exercises too quickly, rather than having them develop sound movement patterns on the ground, before trying to progress to a more difficult variation of the basic movement.
Squats and lunges don’t typically look better on an unstable surface, so if your technique is crap when you are on solid ground, it wont get any prettier when standing on a wobble board. Crap in = Crap out.
SAID
Before I continue, it is important that we pause here to review our SAID principles:
Specific
Adaptation
to
Imposed
Demand
Basically, we get what we train for. Balance and coordination are important aspects of athletics; however, these qualities are also highly specific to the sport in question. If we want to be better at running, cutting and decelerating, then we need to train those tasks. If we want to be better at performing squats on a bosu ball, then we need to squat on a bosu ball. Because adaptation is specific to the demands we impose on our bodies, it would be silly to think that squatting on a bosu ball would aid our ability to squat on the floor, or perform any athletic movement more proficiently.
As stated earlier, a lot of the information regarding unstable surface training has been conducted on athletes who are either injured or recovering from injury. Obviously, if we are a trainer or strength coach, applying research conducted on pathological populations to healthy populations doesn’t seem to pan out.
Additionally, studies still seem to be conflicting on the true benefits of unstable surface training and with the different types of surfaces available (bosu, wobble board, dyna disk, airex pad, etc.), you may get a different result depending on what you use. This seems to be more apparent in highly resistance-trained individuals, where moderately unstable training devices (IE dyna disk, bosu ball, etc) do not produce enough of a challenge to the nervous system.
What about my CORE!!
Increased “core” strength is a common quality that individuals using unstable surface training are trying to seek.
A recent study looked at core muscle activity (rectus abdominis, external/internal oblique, transverse abdominnus, erector spinae) during four exercises – back squat, deadlift, overhead press, and curls; performed under three different trials:
- On the ground with 50% of 1RM
- On a BOSU Ball with 50% of 1RM
- On the ground with 75% of 1RM
(Note: No lifts were performed on the BOSU at 75% intensity because exercises performed on an unstable surface offer a challenge to balance that would make lifting higher intensities potentially dangerous. Therefore, lifts performed on unstable surface are relatively submaximal in comparison to those that are commonly done on the ground.)
The exercises performed on the BOSU ball failed to produce significant differences in core musculature activity in all lifts when compared to exercises performed on stable ground with 75% intensity. Additionally there were no significant differences reported between the BOSU ball exercises (at 50% of 1RM intensity) with any of the exercises performed on stable ground with 50% intensity. The only significant differences noted were between the overhead press and curl performed on stable ground at 75% intensity and the BOSU ball, with the 75% intensity training showing higher activity of the rectus abdominus during the overhead press and the curl showing higher activity in the transverse abdominis and internal obliques. This led the researchers to conclude, “The current study did not demonstrate any advantage in utilizing the BOSU Balance Trainer. Therefore, fitness trainers should be advised that each of the aforementioned lifts can be performed while standing on stable ground without losing potential core muscle benfits.”
This is one stable canine!
Strength And Sports Performance?
As noted above, one of the issues with unstable surface training is that appropriate intensity needed to develop strength cannot be reached due to the balance challenges that performing an exercise on something unstable present. While these balance challenges may be thought of as beneficial, it is important to keep in mind that balance is task specific, and developing appropriate strength is a crucial aspect of training (additionally, as seen in the above study, the challenge to balance didn’t add anything beneficial to the training interventions tested).
McBride et al, looked at force output between an isometric squat performed on a stable and unstable surfaces (balance discs). The isometric squat was chosen so that the subjects could perform the squat on a force plate, where force output could be properly measured. As to be expected, squatting on an unstable surface significantly reduced peak torque and rate of force development. This led McBride and colleagues to conclude, “In terms of providing a stimulus for strength, no discernable benefit of performing a resistance exercise in an unstable condition was observed in this current study.”
These findings are in agreement with Cressey et al who compared unstable surface training to stable surface training in a 10-week training program for Division 1 soccer players. The athletes in both groups performed the same training program except the unstable surface training group performed some of their lower-body exercises on a dyna-disc (small inflatable disc). The stable training group significantly improved their power output in both the broad jump and countermovement jump when compared to the results of the unstable surface group. Additionally, the stable training group significantly improved their 40-yard time compared to the unstable group and had greater trends toward improvements in their 10-yard sprint time as well. Cressey et al, concluded, “These results indicate that unstable surface training using inflatable rubber discs attenuates performance improvements in healthy, trained athletes. Such implements have proved valuable in rehabilitation, but caution should be exercised when applying unstable surface training to athletic performance and general exercise scenarios.”
Just say "NO" to stupid trainer tricks
Final Comments
While there are some studies that show evidence that unstable surface training can have a positive impact on balance (both static and dynamic balance), it is still not certain whether this will have a direct translation to improved athletic performance and skill. As stated earlier, balance is highly specific to the task at hand. Performing exercises on an unstable surface make you better at performing exercises on an unstable surface. It remains to be seen whether this type of training intervention will make you better at playing a particular sport.
If you choose to use unstable surfaces in your training programs, I urge you to come up with sound reasoning and progressions – making sure the client/athlete has appropriate technique on stable ground first – before just throwing this training technique out there, as so many do.
This article reflects my views on unstable surface training based on the things that I have read. I don’t have all the answers, but I can tell you one thing…I am not in a hurry to run out and buy BOSU Balls, Dyna-discs, or wobble boards. I’ll stick to good ole’ fashioned strength training for now.
Patrick
Patrick@optimumsportsperformance.com
References
Wahl MJ, Behm DG. Not All Instability Devices Enhance Muscle Activation In Highly Resistance-Trained Individuals. J Strength Cond Res 2008;22(4):1360-1370.
Willardson JM, Fontana FE, Bressel E. Effect of surface stability on core muscle activity for dynamic resistance exercises. Int J Sports Physiol Perform. 2009 Mar;4(1):97-109.
McBride JM, Cormie P, Deane R. Isometric Squat Force Output And Muscle Activity In Stable and Unstable Conditions. J Strength Cond Res 2006;20(4):915-918.
Cressey EM, West CA, Tiberio DP, Kraemer WJ, maresh CM. The Effects of Ten Weeks Of Lower-Body Unstable Surface Training On Markers Of Athletic Performance. J Strength Cond Res 2007;21(2):561-567.
DiStefano LJ, Clark MA, Padua DA. Evidence Supporting Balance Training In Healthy Individuals: A Systematic Review. J Strength Cond Res 2009;23(9):2718-2731.
Yaggie JA, Campbell BM. Effects Of Balance Training On Selected Skills. J Strength Cond Res 2006;20(2):422-428.
16 comments
Good post, Patrick. I think the take home message here is that you need to know what these exercises are doing and why you are doing them. From a physical therapy standpoint, I see people all the time with balance deficits due to decreased proprioception, decreased strength, and just overall decreased environmental awareness. Some of these patients are older patients with generalized decreased balance, some are athletes or workers who have had a specific injury and/or surgery. From the standpoint of my role, doing balance exercises on compliant surfaces is important to sharpen the neurological connection between the lower extremity and the brain. I try to appropriately progress these patients through a variety of situations. I do not feel that doing a stationary balance exercise on a airex pad (as an example) is going to makes someone’s functional balance better. Likewise, doing a lunge or a squat on a dynadisc isn’t going to improve an athlete’s performance. However, it does help to re-establish the foundation that the nervous system needs in order to perform those higher level balance activities that are necessary for an individual patient’s ultimate goal. Eventually, exercises MUST progress to those which address the specific goal of the patient, whether that is playing basketball, working outdoor construction during the Wisconsin winter, or preparing to hike the Grand Canyon on vacation 3 months after having a scope.
Again, these are likely not the same type of folks you’re routinely working with, and your cited research is well taken when the goal is performance trianing for athletes. Again, just shows the importance of knowing your clients and what their needs and goals are.
Thanks for the good read.
Andy Peterson, PT SCS
Hello Andy,
Thanks for the feedback! It sounds like you have a good understanding of progression with regard to various exercises. Most just tend to throw things at their clients/patients without having a firm understanding of what they are doing. You are correct that one needs to understand their client base and what they are looking to get out of the exercise. The article was written from the perspective of a strength coach/trainer in a regular training environment, not from the view point of a rehabilitation professional. Obviously the goals of those two situations are vastly different.
Thanks,
Patrick
Patrick,
Great post and excellent topic. Many times I see patients who have been working out at the gym with all the “devises” mentioned above and have gone well beyond their limits and abilities and we have to back down. Their trainers have them doing many exercises that are “cool to do” and at the same time keep me busy. The references you list are helpful and hope this post gets read by many.
Michael
Michael,
Thank you for your comments. Glad you enjoyed the article.
As you have observed, an training modality (unstable or stable), when improperly prescribed will certainly produce undesireable results.
Keep up the good work!
patrick
Of course, I have to bust your chops on one comment: “Commonly in rehabilitation settings, where most of the research on unstable surface training has been conducted, clinicians will try and advance patients to these exercises too quickly, rather than having them develop sound movement patterns on the ground, before trying to progress to a more difficult variation of the basic movement. ” I will respectfully disagree.
If someone needs balance challenged, for whatever reason, to invoke the desired balance strategy – be it hip, ankle or stepping – one of the easiest ways for a clinician is to implement an unstable surface. We can choose between high density foam surfaces, wobble boards, the air discs, the BOSU, and high tech stuff like force platforms and things like the Smart Balance Master by Neurocom – lots of options out there. The unstable surface isn’t just for doing the types of activities you captured in photos, but also to provide unexpected perturbations. There isn’t a way to easily help the human body learn the strategies on the ground with movement patterns because the strategies I mentioned are reflexive in nature. In my opinion, as long as the person has decent lower extremity strength and can be full weight bearing, unstable surfaces can generally be introduced immediately. Initially, I highly doubt in physical therapy that people are immediately performing squats and lunges. The goal isn’t by any means for strengthening, but in the case of balance deficits, progressively challenging the body to increase awareness and improve proprioception.
~Snippets
Thanks for your comments Snippets.
I understand what you are saying regarding the challenges that the unstable surface presents and trying to develop some proprioception. But, just standing on one leg creates a proprioceptive rich environment. Closing your eyes (or even one eye) would do achieve the same thing. All I am saying is that most people can’t perform exercises properly on the ground, so performing them on an unstable surface doesn’t make them better – regardless of of the fact that this is not for “strength” – sloppy exercise is sloppy exercise. If the exercise looks good on the floor, and then you want to challenge the balance mechanism, then I guess that would be one way to use this modality.
Patrick
You have a point, Patrick… but is it considered a “skilled” service for a patient to do what you are suggesting in a clinic under the watchful eye of a physical therapist? Generally, nope…If the person can do the stable surface safely with some upper extremity assist, as needed, the person can do the activity at home as a home exercise program. As a person learns, the activity on the unstable surface is always “sloppy.” I’ve never seen it initially neat and perfect. If it were nice, neat and normal, there would be no reason to introduce the activity into the treatment plan.
~Snippets
Pat, I may just print this and show it to every patient I get that says “Well I like to do as much as possible on the BOSU because my core works more…”
Also, just read in the newest Jour. of S&C that it doesn’t matter which side of the BOSU you stand on, the EMG activity in the ankle stabilizers is statistically the same, but you probably already read that.
Snippets – I think that Pat is not arguing that initial movements on the BOSU shouldn’t be sloppy, but what he is saying is that you should not put someone one the BOSU in a strength and conditioning setting if their movement patterns on solid ground are poor to begin.
Yep, Mike hit it on the head. I am not disagreeing with what you are saying Snippet. It doesn’t matter to me how people want to progress their clients. But, what I see is that people tend to rush them into a more advanced progression without having the fundamental skill learned yet. Obviously from the article, I am not a big “unstable surface” guy, but if I were using that modality, I would use a progression like this:
Stable bilateral movement > Stable unilateral movement > Unstable bilateral > Unstable unilatera
Obviously the unstable stuff is not going to look perfect (which is the point of unstable surface training…or any “imperfection training”, as Mel Siff used to call it). But, you should have a solid understanding of how to perform the movement on stable ground before progressing.
Patrick
Patrick – Thanks for the article. I have to admit that throughout my career I’ve been in situations where a new training tool comes out (like any of the unstable items you mentioned) and then see other trainers / coaches using them and feel almost obligated to try and incorporate it. Whether it be a client asking about it because it looks “fun” or because I have a sense of being “left behind” some great new trend.
I remember when the BOSU came out, very difficult to not feel like I needed to incorporate it.
Luckily, over the years I’ve learned that there might be a need for various tools in training, but sometimes there is not need and adding tools may actually be making the training worse.
As your article and the conversation in the comments point out, it depends on client ability and client goals/outcomes. Right now I’d have to say that most of the people I work with do not belong on anything unstable. Thanks for giving me something I can point folks to the next time I have to discuss why.
Excellent article! I’ve been trying to fight this battle on stability training for a while.
Another thing to consider is that the research shows that often with unstable training you get a high degree of co-contraction of agonist/antagonist, which obviously for athletic performance is generally not something we want.
Gary, thanks for the comments! It is amazing when something “new” comes out and people just flcok to it!
Steve, great stuff. You are correct about co-contraction on the unstable surfaces (they show this a bunch in upper body exercises performen on unstable surfaces; which I left out of this article because I wanted to focus mainly on lower extremity movements).
Patrick
Great article! And is it just me, or does that doggie look slightly embarrassed at being photographed on a Bosu?
Thanks, Blue Tuna.
patrick
Great article! I agree that many people who use such devices are not sure why they are using, or how to properly use them for that matter. There is always equipment that will benefit some while others should stay far away from. Mainly, the untrained gym rats hopping on a new trend!
great article Patrick – this stuff really gets on my nerves – an important point (on bosu balls especially) is the amount of pronation that goes on just to keep upright – as you say theres no point to it at all
Leave a Comment