An experienced coach will watch typical people run, jump, land, squat, or deadlift and cringe. Sadly, most people’s form just sucks. But why does it suck? Why do knees cave and backs round? Is it lack of strength or lack of motor control?

I think that people learn to move this way over time because it’s more “efficient” from an energy-conservation standpoint. Let bones, ligaments, and fascia do more of the work so muscles won’t have to work so hard. When the back rounds in a deadlift, the ligaments and fascia eventually stabilize the torso (in a rounded position) and allow for the pull to take place. When the knees collapse when landing, the ligaments stabilize the position of the knees and the glute medius has better leverage for dissipating the energy at the hips.

While this is indeed “efficient” from an energy-conservation standpoint, it is incredibly “in-efficient” from a long-term joint health standpoint.

So the question now becomes, “How do we best go about fixing people’s natural inclination toward crappy movement patterns?”

I used to think that fixing people’s form on things was a matter of getting muscles strong. It’s not. You have to retrain their motor patterns.

X-band walks won’t fix someone’s valgus collapse during squatting; teaching proper form on squatting and having them practice it over and over will fix their form. The same applies to jumping, landing, sprinting, etc.

Altering technique has much more to do with the retraining the nervous system than it has to do with increasing strength. Most people already have the strength to perform a particular task, but they’ve memorized a faulty motor program and it takes time and concentration to get them moving better.

It is true that getting stronger and more powerful has more to do with increasing muscle size and neural drive via maximal strength training, explosive strength training, plyometrics, sprints, sledwork, etc.

However, if technique isn’t good during heavy or explosive movement the body will eventually break down. This is why you have to groove proper technique first and then build upon that base.

There are many names for technique training (neuromuscular training, neuromuscular reeducation, motor control training, etc.), but suffice to say you’ll reach your goal of improving form much quicker through focusing on form rather than utilizing creative strengthening exercises. This isn’t to say that you shouldn’t do glute activation work and other specialized muscle activation techniques. Just please understand the following:

Working with technique is KING when it comes to fixing form on anything; getting a particular muscle stronger only helps when that newfound strength is coordinated into the motor program through practice and repetition.

In this video I elaborate upon this concept:

Several weeks ago I wrote a post reviewing a study on Christophe Lemiatre and what makes him so darn fast. The study was conducted by French professor JB Morin; an incredible researcher in the field of sprint biomechanics and speed development. JB was kind enough to sit down and answer 21 questions I threw at him. Understanding sprint biomechanics is not easy, and there are many different theories out there; some more evidence-based than others. Luckily we are learning more over time with excellent studies emerging on a monthly basis. This interview should help improve your understanding and confidence in sprint mechanics and the determinants of speed.

1. Hi JB, first off let me congratulate you for undertaking one of the most amazing studies I’ve ever read. You guys are coming out with some really great research! What is your background in sports and academics?

Thanks Bret. In academics I’m a Sports Science MSc, and I did a PhD thesis in Sports Science as well. In sports, I was a 400m hurdler. At age 22 I tried trail running for a while, but then I had knee-trouble, so I switched to mountain biking and now I’m a MTB and road cyclist. Interestingly, cycling research regarding mechanical effectiveness and the ratio of forces has been around for over 30 years, which gave me some of the ideas for my recent research.

2. Interesting! Now let’s get right to it. Based on your findings, what makes Lemaitre so damn fast?

From what we measured on the specialized treadmill (there could be other things we didn’t measure…maybe he has a huge amount of fast-fibers but we don’t know this yet), he has a better ability to orient the total force vector with a forward incline (he doesn’t have more total force production than his peers, or even specialists from other sports than athletics), and he has the ability to produce the highest horizontal force amongst his peers, and especially at faster velocities.

3. Can you please explain this in Laymen’s terms? Maybe you can provide an analogy?

At 6m/s on the treadmill, he’s producing more horizontal force than the National sprinters. Some of the non-specialist sprinters couldn’t produce any net horizontal force at that speed on that treadmill.

For the analogy, say that if he were pushing a big car, at the beginning he wouldn’t be that much better than his peers. But as the car built up speed, he’d keep getting better than his peers due to his ability to produce more horizontal force at higher velocities. Eventually he’d be the only person amongst his peers who could produce force as the car sped up sufficiently. This is what makes Lemaitre superior in this regard.

4. Brilliant analogy! I think that effectively sums it up. This study was performed using your special torque treadmill. How does the treadmill affect the force and power measurements compared to overground sprinting?

First, the treadmill allows for the measurement of force and power. It affects velocity in that the treadmill sprinting is slower than what’s seen overground (although these two velocities are very well correlated, as we’ve observed and recently reported in a recent study published in the same Journal). We’ve recently completed a study to determine how the forces are affected, but the values are within the range of what’s seen with overground force plates in terms of Newtons. For sure, the locomotion is indeed different since you’re tethered at the hips, you’re not moving forward, and you’re spinning the torque treadmill with your feet (which is not the same as overground running).

But the fastest sprinters overground were also the fastest sprinters on the treadmill, so the treadmill still allows for some interesting comparisons. And all of our studies with this treadmill share the same design, in which we compare the mechanics of subjects from various sprint levels on the same device.

5. Some experts might doubt the study you conducted based on the premise that the treadmill can’t possibly produce accurate data. Is there any merit to these folk’s concerts, and if you were to reproduce the study using a hypothetical 100m track of continuous force-plates, how do you think the results would differ?

The treadmill doesn’t allow for the same top speed velocities to be reached. For this reason, I won’t publish any data on “top speed” – in fact if I were a peer-reviewer for my own data I wouldn’t allow it to be published since the forces and velocities are different.

So we can’t answer the question about forces right now for top speed as we don’t know enough. But I think we’ll duplicate Weyand’s data – faster sprinters put more force into the ground. Part of our results from the “Lemaitre study” confirms this. But we’ll learn more since Weyand’s study only reported and discussed vertical forces; we’ll be able to look at all of the forces (vertical, braking, propulsive, and resultant).

Last, but not least, we are about to send for publication new and interesting results, this time obtained during real overground accelerated runs. Part of these results clearly confirms the treadmill ones, hopefully they will be published soon. If so, then the discussion will revolve around sprint biomechanics, rather than (or in addition to) treadmill vs. field measurements.

6. What’s the deal with braking forces, can we eliminate them completely during maximum speed running, and is some level of braking forces ideal to allow for more time for force development?

Until we have more clear data, my thought is that a certain amount of braking is necessary. At maximum velocity (which is constant speed), horizontal braking forces and propulsive forces cancel each other out (horizontal net ground reaction force is null at constant speed). You can have large braking and large propulsive forces, or you can have small braking forces and small propulsive forces. As long as they cancel each other out during max and constant speed then that speed is maintained and you won’t decelerate.

But I don’t think it’s wise to try to completely eliminate braking forces, especially during the acceleration phase of a sprint; I think there is an ideal amount of braking force needed to “stall” the neuromuscular system and allow for enough time for the build-up of sufficient force from the muscles. The latter resulting in greater amounts of propulsive force produced. There’s probably an optimal window, with too little or too much braking being less efficient. Furthermore, the center of mass “falls” down during the braking phase, and should this braking phase be too short, the overall orientation of the ground reaction force during the propulsive phase might be too vertically-oriented (and thus not enough horizontally-oriented).

I’m excited to very soon test this hypothesis with the data we collected during overground 40-m sprints. Last week, a paper published in the Journal of Strength and Conditioning Research (Kawamori et al.) revealed that the 10-m performance was positively correlated with the net horizontal impulse measured at the 8-m mark (this is mechanically logical), and that propulsive but not braking impulse was correlated to this performance. In addition, similar results were put forward in a classic paper by Joseph Hunter a few years ago, at the 16-m mark. This contradicts the idea I propose here, but my reasoning considers the entire acceleration phase, and although very interesting, Kawamori et al.’s data only focus on the first step and the step at 8m, in team sports players. Their study is also interesting in that neither vertical nor resultant impulses were correlated to 10-m sprint performance, only horizontal impulse was…As Hunter wrote: “the possibility of braking having some advantages could not be ruled out.” This is what we will test very soon with force data collected all over 40-m accelerations.

All this shows us that efficient sprint biomechanics research forces one to be humble since getting “ideal data”, i.e. overground measurements plus over several steps plus in top level athletes plus in competition conditions is a very tough work! Each study should therefore be considered as a little contribution bringing us one step closer to this “holy grail”.

7. What about vertical forces, should we try to maximize them during maximum speed running?

I agree with the hypotheses and conclusions of Weyand on that, I think you must be able to produce high vertical forces to run at high top speed, but you reach a limit. And as you speed up, you have shorter and shorter ground contact times. So you must be able to produce great vertical forces in exceedingly shorter times. But I don’t think that the fastest sprinter automatically produces the greatest maximum forces during sprinting; you want to produce sufficient vertical force rapidly in order to raise the COM but not too much as that would negatively impact speed. Because it has applications in many other sports than athletics only, I’m much more interested in the determinants of maximal acceleration rather than maximal speed.

8. And what about horizontal propulsive forces, these forces are most correlated with maximum speed, correct?

Again, we can’t say for certain; we don’t have the data yet for maximum speed. My guess would be yes. Net horizontal forces are probably more highly correlated with maximum sprint speed, and maybe more with maximum acceleration than vertical forces. But again, we don’t clearly know this yet.

9. Many sprint experts believe that since net horizontal force is zero at maximal speed (since braking forces are equal to propulsive forces), that they’re not critical and vertical force now becomes the more important factor since it helps get the sprinter off the ground quicker. What’s the problem with this line of thinking?

At top speed, you need to produce sufficient vertical force. You’re not accelerating anymore. However, since you can’t get rid of braking forces, you must have the ability to apply great propulsive forces while your leg is moving very fast to prevent deceleration. So if you want to improve top speed, you need to be able to produce greater horizontal propulsive forces. In fact, mechanically-speaking, there are two possibilities: either you are able (at top speed) to produce small amounts of horizontal braking impulse, and then the propulsive impulse needed to maintain a constant speed will be small, or you produce a larger braking impulse, and then…you’ll need a high propulsive impulse to “compensate” and maintain constant speed. If your propulsive impulse does not match your braking one, you’ll decelerate.

Thus, I really consider the acceleration phase and the top speed phase different from this point of view. Although I hypothesize (our data might soon prove me wrong…or not) that you need a certain amount of braking impulse during the acceleration, I think it should be reduced at top speed. At this moment, the distance your center of mass goes forward during the contact, and the net impulse you can produce, becomes critical. Furthermore, at this moment, I think that the backward push of the (almost totally extended) leg is crucial. And I also hypothesize that the role of hip extensors is underestimated. Although it appears from former studies that these muscles “shut down” around mid-contact, their action before contact (during the “pawing action”) and during the braking phase might be determinant.

10. Do you think that we can cue sprinters to affect their force production on the ground, or is the ground contact time too short to do so?

The idea is to be able to produce the most force while on the ground. I think you can indeed affect force production while on the ground through cueing, but the goal is not to try to stay on the ground for longer times just so the sprinter has more time to produce force. I’m not sure if cuing for pawing-back or popping off the ground rapidly would lead to better sprint times – the athletes probably figure out the optimal blend all on their own. I must say here that “pawing-back” the leg while in the air just before contact or while on the ground might be two different actions, maybe two different abilities, and maybe not equally efficient in leading to a high amount of horizontal impulse. This is another hypothesis I’d like to test.

11. Assuming that two elite sprinters weight the same and have identical ground-contact times and vertical forces, does the sprinter with the greater horizontal force per stride run faster?

My guess would be yes; he would accelerate more during the initial portions of the sprint and reach a higher top speed.

12. Usain Bolt and Christophe Lemaitre have the insane ability to continue accelerating through a substantial portion of the 100m sprint. What do you attribute this to?

If I remember correctly, if you take the speed-time curve of Bolt, he accelerates up to something like 80m. For Lemaitre it’s more like 65m, and he does indeed decelerate. Everyone decelerates, but he decelerates less than his competitors. Bolt and LeMaitre have excellent “endurance” for net horizontal force production. Each of them is amazing at the 200m sprint. If Bolt wanted to, he could probably break the 400m record. They have an uncanny ability to transmit forces, and I bet they have great foot/ankle properties that allow for optimal transfer of power from the glutes and hamstrings down into the ground. I like the approach of “producing AND transmitting force effectively to the supporting ground”. Sprint training should focus on both.

13. What makes sprinters slow down? As they fatigue, what happens to their forces and power output?

I don’t know. Until we get sound measurements I can’t say. I’d guess that you’re getting neuromuscular fatigue which lowers your vertical and propulsive forces. In addition, the neuromuscular fatigue might reduce the ability of the feet to transmit force into the ground, since the foot/ankle deforms more at the end of the sprint compared to the beginning of the sprint. But until we have sound measurements, these are just hypotheses.

14. What muscles do you feel are most important for speed? Is every muscle in the body equally valuable or are some more important than others?

Speed is vague. You need knee extensors and you need plantarflexors. But I really think you also need powerful hip extensors to accelerate. At full speed, you need stiff ankles and powerful leg extensors. You need it all! Remember that at top speed your lower limb touches the ground in an almost-fully-extended position. Anatomically, the muscle groups generating a backward motion of the limb are rather hip extensors than knee extensors (the knee is almost fully extended). That said, you need it not to “deform” too much, same for the ankle. It is an easy answer to say “everything is necessary”, but I think that as speed increases during a typical acceleration, and at top speed, producing the force, and transmitting it to the ground predominantly relies on different muscle groups. Especially, as speed comes close to maximum, the ability of ankle and knee “stabilizers” to allow these joints not to deform too much during the huge impacts at each step might be a prerequisite for an efficient propulsive action of hip extensors…and a high horizontal impulse production.

15. Now let’s talk applications to training. Do we just need powerful hips or is there more to the equation?

As I just mentioned, you need a strong motor in the hips (and in the knees and ankles, for the early phase of acceleration, from a crouched position). But you also need stiff ankles (and knees as speed increases) to transmit the force with effectiveness. You can have a superior motor (glutes and hamstrings, or even quads) but if you have a flat tire (weak ankles or knees that deform too much at the ground), you won’t move very fast.

16. I know you’re interesting in cycling as well. Does this same principle apply to cycling?

Producing and transmitting force in cycling is paramount. If you have big glutes / quads / calves but your ankle stabilizers are tired, your heel goes down, your foot goes up, and your push is wasted. When I train cyclists, I have them do exercises to work their ankle strength and endurance (just as I would do with basketball players) and they look at me like I’m insane. They say, “But we’re cyclists, why are you giving us track exercises?” I have to educate them about the importance of the ankles.

17. What are some drills and exercises that you recommend for sprinters?

Exercises that put the body at an incline such as sled work, towing, elastic bands, and incline sprinting are great.

Speed, speed, speed is critical. You don’t need to obsess with weight; you need to think “explosion.” You need force, but you need to produce force very quickly. Don’t forget about velocity! Whatever the load you push or draw, focus on doing it as fast as possible.

I also like to train the ankles for endurance. For example, take a 20lb barbell on the shoulders and jump from right foot to left foot while on the balls of your feet, or jump with a high frequency on one foot only for 20 reps, then on the other, and so on, or from right to left over a lane line, etc…. Do this for 3 minutes – they’ll burn like crazy. This will build tremendous ankle endurance. In addition, these muscles are involved in our overall balance while standing, so they have a high endurance, don’t hesitate to “burn” them until you can not stand on your feet, they recover very fast.

18. Are there any drills and exercises that you feel are overrated for sprinters?

Everything is good, but in the right amounts. Deep squats are good. But too much of them and with too much weight is not ideal. Coaches usually employ excellent exercises but the dosages are not always ideal. In general, never stray too far from velocity. But I have to admit, many coaches over-emphasize the squat. For many sports such as soccer, their quads are already strong and they sometimes need to focus more so on their posterior chain, for both performance and injury prevention reasons…

19. Are there any cues that the French sprint coaches are giving to the French sprinters that differ from the norm?

For what I’m aware of, there is no consensus in France and every coach has his own view and practice. For instance, some of them are not too concerned with maximum strength. When we say, “strength training,” all too often people assume “heavy strength training.” But some of the guys in France use lighter loads and work more on the velocity side of things, with very specific strength exercises. Although I don’t know how people train all over the world, I think we also do more work for the foot/ankle complex.

In France, overly muscular athletes have often been perceived as anabolic steroids users, and it is possible that this has refrained coaches from using heavy strength training too much. France has a huge anti-doping stance, and ironically this might have benefited France because we’ve figured out ways to improve our sprinters by improving their power through velocity and/or force application technique, and not so much through force and bigger muscles.

20. Any insight as to how Christophe Lemaitre trains?

Lemaitre has an outstanding ability to transmit the force onto the ground, and I think he is also very “endurant” in doing so. This is his strength. But I feel he could benefit from improving his ability to produce force. He has excellent sprint endurance too. I’m curious to see if he’ll improve his 100m time this year, but I think he’ll definitely improve upon his 200m time. It’s common knowledge here in France that Lemaitre never did any serious strength training prior to breaking the 100m barrier. Maybe a couple sessions per week for a couple months, but never anything very intense or drawn-out. In a newspaper article here in France, his coach stated that Lemaitre’s maximum deep squat was 240 lbs, which many track coaches would believe to be incredibly low. These days he’s doing a little more maximum strength work, but I don’t expect it to have too much of an impact right off the bat as it takes time for training gains to come to fruition.

21. Thank you very much for your time JB! It is much appreciated. Last question: Do you have any exciting research in the woodworks?

We certainly do. We’re doing some testing on acceleration using overground force plates to see if we get the same measurements that we did in the treadmill study. So in essence we’ll be critiquing our own study on the treadmill by comparing to overground sprinting.

We’ll also be looking at sprint speeds, isokinetic torques for the quadriceps (knee extension), hamstrings (both knee flexion and hip extension), glutes (hip extension) and foot motion during the sprint cycle to see what correlates best. Data have now been collected, and we’ll discuss the role of hip extensors in the “pawing” action, both in the air and then during contact, and in turn in the horizontal force production during accelerated runs. We synchronized EMG, 2D video and treadmill GRF measurements, to try and see what muscle groups are the most involved and the most efficient in generating horizontal force production.

Many of my readers know this, but once upon a time I was a high school mathematics teacher. Last year, while in Auckland, I instructed plenty of labs as well as a master’s level summer school course titled Enhancing Muscular Performance. Point being – I am a teacher at heart.

These days I’m attracting a ton of Exercise Science students to my blog. I’m much more interested in teaching my students how to fish, rather than feeding them a fish.

One vital skill that I would like for my blog readers to possess is the ability to think critically. You should absolutely question everything. Question what I tell you, question what you see in the research, question what you hear from blog writers and experts, question all of it! Here’s the late George Carlin on questioning everything:

I am very appreciative of the folks who dare to speak up in the name of science. One of the guys I admire most is Greg Lehman. In fact, if you recall, I linked to his blog a couple of weeks ago. He and I have been corresponding lately and I asked him to write a review of the recent foam rolling research for my blog. Here’s what Greg had to say:

Greg’s Critique of the Foam Rolling Article

I read the recent study by MacDonald et al (part of David Behm’s great research team in Canada and someone I have asked for research advice in the past a great deal) that Bret reviewed on his site.  I think the study is an excellent start into looking into the prevalent practice of foam rolling and I hope that it was spur a lot of other research.  But, I’m now going to give a mini critique.  I don’t want to be a contrary a-hole (although I know that’s how it looks) but I have always thought it was important to question everything we do.  I am even harder on myself.  I will readily admit that I don’t have a lot of definitive answers and this is why I am indebted to researchers that commit the time and effort into these works.

My Bias

Believe it or not I want foam rolling to be effective.  If proven effective, I think would then be a great tool that empowers patients and athletes to do something actively, that is self directed and that they would get benefits from without paying an arm and a leg.  You don’t have to rely on someone else with a foam roller.  I advocate this self reliance for my patients.  Further, the background behind foam rolling is founded on fascial adhesions, thixotropy and tissue health which as a manual therapist doing ART I would benefit from these theories being proven.  There is nothing like the relief you can feel after having resolving some cognitive dissonance.  But, I continue to question.  I want to be convinced soundly and for this I remain on the fence.

Limitations

Every study design makes choices and when we make choices those choices lead to some limitations.

The control group was not a true therapeutic control group.

Meaning there was no “sham” intervention given.  The participants all knew that they were being foam rolled and may have also likely known that it was expected that they would have changes in their function.  The control does not control for the fact that something was done to the subject’s limb.

The warm up was not consistent with standard practice

This unfortunately would not replicate what is typically done in usual sport.  If you took these athletes through a standard warm up, with dynamic activities and prepared them for sport would you not expect to have an increase in ROM from that?  Would foam rolling provide any greater benefit from what is considered best practice currently?  Again, this is not a knock on the study design; it helps simplify things for their research question.  But, it does limit its immediate relevance to usual practice

The experimenters were not blind to the interventions.

This is not very relevant for the strength testing but is quite relevant to the ROM assessment.  The ROM assessment used a goniometer that is often quite subjective.  When you use a goniometer you line up the ends on landmarks that you palpate and being off slightly can change the readings you get.  This is amplified when measuring larger limbs.  Further, the experimenters were the ones actively controlling the amount of knee flexion that the subject had.  The experimenters pulled the knee into flexion to the point of pain experienced by the subject.  This is hugely subjective and can be easily manipulated by the tester (consciously or subconsciously).  If you are the experimenter and you know that they just foam rolled, it would be easy to subconsciously coax a few more degrees out the subject.  The subject is also being handled by the experimenter and may feel that they can ‘give” more as well – subject knows they were just foam rolled and will let tester pull them a little more.  There is a huge interaction going on here between subject and tester.  I am suggesting that all of this is not at the conscious level of the experimenters.

The ROM testing was too subjective.

It is possible (although extremely difficult considering the joint that they chose to study) to create a rig that pulls the subject’s leg into flexion with the same force each time.  We could also measure ROM with reflective markers on three points (ankle, knee joint and greater trochanter) and measure this digitally.  Having this objectivity is important because there are too many errors that can occur with testing ROM and with such small changes (10 degrees). We want to make sure that there is really a true change not some study artefact.

Discussion regarding self myofascial release and fascial adhesions

Bret really seemed to like this part of the paper.  I thought it was a nice review of the theory but that it was presented like it was fact.  If you notice the references for this section they are all course notes or peer reviewed papers that actually did not study fascial adhesions, fascial properties or thixotropy etc.  For example:

“When fascia loses its elasticity and becomes dehydrated, fascia can bind around the traumatized areas, causing a fibrous adhesion to form. Fibrous adhesions are known to be painful, prevent normal muscle mechanics (i.e. joint range of motion, muscle length, neuromuscular hypertonicity, and decreased strength, endurance and motor coordination) and decrease soft-tissue extensibility (5, 15, 36).”

Again, I would love for this to be true but it is still a theory and not strongly supported. If anyone has any research that really looks at these beliefs I would love to read it.

An apology

You can certainly say to me “hey jackass, why don’t you do the research yourself?” Yup, this is a good point and it’s why I am not criticizing the researchers but rather just pointing out the normal gaps that occur when we conduct any experiment.  I know the huge amount of thought and work that went into this good study.  It is very easy to critique something and I don’t doubt that everything I have written above the researchers have also already thought about.  That is why we have follow up studies and multiple research teams.  The researchers made choices and this causes certain limitations.  If they made other choices than different limitations crop up.

Bottom Line – What does this mean for practice?

This paper certainly suggests that there is no decrement in performance variables studied (but who knows about dynamic tests or injury) so it is hard to argue against using foam rollers day to day.  However, you can look at this another way, since there was not change in force parameters and the ROM changes could have been an artefact of the experiment, perhaps foam rolling does nothing at all and there is something else out there that we should be spending our time doing before or after sport.  If we just settle on foam rolling are we missing out on something else?

So if you are already foam rolling you will probably continue and if you aren’t foam rolling your muscles maybe you should? I don’t know. How is that for certainty? I look forward to great research to follow.

Thanks for reading.

Greg

Thank You!

I want to issue a huge thanks to Greg and people like Greg who fight hard for scientific advancement. This is just the first small step along an undoubtedly long line of foam rolling and myofascial research and we’ve just skimmed the surface.

As an industry (Strength & Conditioning as well as Physical Therapy), we owe tons of gratitude for critical thinkers as they force us to expand our boundaries in the quest of knowledge and scientific advancement.

You should NEVER think of these folks as “contrarians.” They are CRITICAL to the evolution of our field. However, there are indeed many contrarians out there, and the trick is to be able to spot the critical thinkers in the midst of contrarians. Three such folks are Greg Lehman, Paul Ingraham, and Jason Sivernail.

Greg Lehman

I freakin’ love the way Greg thinks. I’m glad that certain guys care about the exact science and not just about popular theories, and Greg is one of these guys. You can trust his integrity. Here are some of his best articles:

Are the psoas and iliacus the only hip flexors above 90 degrees? Questioning this common belief.

Are you sure your hip flexors are tight? If so, why and who cares?

Stop foam rolling your IT Band. It can not lengthen and it is NOT tight.

Stretching Muscle: A brief summary on what it does.

Why do people feel stiff? Are your muscles really tight?

Plenty more good stuff to see on Greg’s site. He’s smart as a whip and you should definitely read his blog.

Paul Ingraham

Paul is a lot like Greg – an incredible scientist with a serious disdain for pseudoscience. It is very important to question everything and we’re incredibly luck to have folks like Greg and Paul who will buck trends in the name of scientific advancement. Here are some of Paul’s best articles:

“The fascia will make everything better”: a pattern of flawed clinical reasoning about fascia

Why “Science”-Based Instead of “Evidence”-Based?

Extraordinary Claims

Quite a Stretch

Does Massage Therapy Work?

Stand Up Straight

The Humble Therapist

Plenty more where this came from on Paul’s site. I highly recommend Paul’s blog.

Jason Silvernail

Unfortunately Jason doesn’t currently have a blog, but he frequently posts in the SomaSimple forums.

Click here to listen to a Recent Interview with Jason.

There are plenty more great critical thinkers out there but these links will get you started.

A couple of awesome studies have recently emerged and I want to alert my fitness friends about the news. One of the article pertains to foam rolling, and the other pertains to breathing training. Many folks in the S&C industries have been skeptical about these methods, and finally we have some good support for their inclusion in our programs. Bravo to some of my colleagues for being “ahead of the research.”

1. Foam Rolling Increases ROM without decreasing Muscle Activation or Force

First off, I’d like to mention that THIS ARTICLE (the link takes you to the abstract – it’s not on Pubmed yet), just published ahead of print, includes an excellent write-up on how foam rolling is proposed to work. Here’s a brief excerpt:

Fascial restrictions often occur in response to injury, disease, inactivity, or inflammation, causing fascial tissue to lose elasticity and become dehydrated. When fascia loses its elasticity and becomes dehydrated, fascia can bind around the traumatized areas, causing a fibrous adhesion to form. Fibrous adhesions are known to be painful, prevent normal muscle mechanics (i.e. joint range of motion, muscle length, neuromuscular hypertonicity, and decreased strength, endurance and motor coordination) and decrease soft-tissue extensibility (5, 15, 36).

Myofascial release (MFR) therapy is a manual therapy technique developed by John F. Barnes (5), to help reduce restrictive barriers or fibrous adhesions seen between layers of fascial tissue. A new technique of MFR termed self-induced myofascial release (SMR) has become of increasingly common practice for treating soft-tissue restrictions. SMR works under the same principles as myofascial release. The difference between the two techniques is that instead of a therapist providing manual therapy to the soft-tissue, an individual uses their own body mass on a foam roller to exert pressure on the soft-tissue. The SMR technique involves small undulations back and forth over a dense foam roller, starting at the proximal portion of the muscle, working down to the distal portion of the muscle or vice versa (28). The small undulations place direct and sweeping pressure on the soft-tissue, stretching the tissue and generating friction between the soft-tissue of the body and the foam roller. The friction generated from the undulations causes warming of the fascia, promoting the fascia to take on a more fluid-like form (known as the thixotropic property of the fascia), breaking up fibrous adhesions between the layers of fascia and restoring soft-tissue extensibility (32).

The authors hypothesized that foam rolling would indeed increase joint ROM, but that it would also decrease muscle activation and force due to prior research they’d seen involving the effects of massage on EMG and spinal motoneuron excitability. The authors were surprisingly wrong about their second hypothesis.

Methods

They had subjects foam roll their quadriceps like this (the one leg method) for 60 seconds, rest 30 seconds, the repeat for 60 seconds.

The authors measured maximum knee extensor force production, rate of force development (RFD), rectus femoris muscle activation via EMG, and knee flexion ROM when in a half-kneeling lunge position with the rear hip extended (sort of like what’s seen in the position shown in the video below).

Findings

This is the very first peer-reviewed study that examined the effects of foam rolling. Here’s what they found:

• Two minutes following the foam rolling, flexibility was increased by 12.7% (11 degrees), and ten minutes following the foam rolling, flexibility was increased by 10.3% (9 degrees).
• Foam rolling did not impede voluntary muscle activation, force or evoked contractile properties. This cannot be said of regular massage or static stretching.
• Following foam rolling the negative correlation between ROM and force production no longer existed.

Thoughts

Obviously this is only one study and more research is needed, but to me this lends a TON of credibility to what the best practitioners already knew instinctively; which is that foam rolling enhances ROM without diminishing neuromuscular performance.

I’d like to see research showing the effects of foam rolling on subsequent sprint performance.

Somewhere out there, Mike Boyle is doing the Carlton dance.

On a personal note, my favorite foam roller is the Rumble Roller (no affiliate link).

2. Breathing Training Improves Posture

There have not been many studies in the literature showing how posture can be improved, though many coaches and therapists have their theories. Lately, breathing training has become more popular in the industry. In particular, diaphragmatic breathing has received a lot of attention. THIS STUDY (click to download the full paper) recently emerged showing that breathing into a SpiroTiger (no affiliate link) improves posture and trunk flexion strength. Here’s a SpiroTiger in action:

Methods

Subjects breathed into the SpiroTiger for 10 minutes three times per week. This trains the inspiratory muscles and expiratory muscles.

The researchers measured the spinal curve (thoracic and lumbar), pulmonary function (forced vital capacity and forced expiration volume in 1.0 seconds), and isometric trunk flexion and extension strength.

Findings

This is the first study of its kind to be conducted. Here’s what the authors found:

• Thoracic kyphosis decreased by 13.1% (5.5 degrees)
• Lumbar lordosis decreased by 17.7% (3.1 degrees)
• Pulmonary function improved (force vital capacity from 4.1 to 4.3 Liters and forced expiratory volume in 1.0 seconds from 3.4 to 3.7 Liters)
• Trunk flexion strength improved by 10.6% (from 695 to 769 Newtons), whereas trunk extension strength was unchanged

The authors offered some explanation as to the findings in this excerpt:

Abe et al (32) reported that the transverse abdominal muscle is the most powerful in the abdominal muscle group with respect to respiration. The transverse abdominal muscle may have been specifically targeted in this exercise. This important muscle is a keylocal stabilizer. Contraction of the transverse abdominis increases intra-abdominal pressure, which leads to lumbar straightening (33). In addition, a rise in intra-abdominal pressure presses the rib cage upward and effectively allows the extension of the thoracic vertebrae (34). In addition, we attribute the decrease of thoracic curvatures to a stretching effect on the thorax. In a previous study, Izumizaki et al (35) reported that thoracic capacity and rib-cage movement were changed by thixotropy, which is the exercise of maximal expiration from maximum inspiration. The stiffness of the rib cage leads to thoracic kyphosis (3). In this study, repetitive deep breathing resolved the stiffness of the ribcage and straightened thoracic kyphosis. This process maybe responsible for altering the spinal curvature.

Thoughts

I’d like to see this study duplicated…I’m a bit skeptical. The study design and findings looked legit though. If this is indeed true, this is huge.

It suggests that spinal posture can be improved by simply training the breathing muscles! It is not easy to alter spinal posture, so this could become very important over time if future studies repeat the findings. And the study duration was only 6 weeks long; which is short for a training study.

The authors didn’t pay specific mention to the diaphragm, which is incredibly important and could explain some of the findings through various mechanisms.

Perhaps the improved posture that strength coaches and personal trainers see with their athletes and clients isn’t so much attributable to increased trunk strength but inner unit strength instead.

This type of breathing training shouldn’t be confused with diaphragmatic breathing “re-education” that is popular these days. This was more like maximal endurance breathing training.

Furthermore, the study shows that you can increase trunk flexion strength by 10% without even training trunk flexion!

I’d like to see the effects of different protocols on posture and different types of strength. For example, breathing into the SpiroTiger for 10 sets of 30 seconds five times per week for six weeks and its effects on posture, pulmonary function, IAP capabilities, and isometric deadlift strength.

That’s all folks!

Given that my friends Marianne Kane and Tony Gentilcore have recently written blogposts discussing their sacroiliac joint issues, I felt that it would be a good time to jot down some thoughts, findings, and experiences with this confusing joint.

The biomechanics of this joint are not easy to comprehend, and to be perfectly honest, in the past year I’ve read at least a dozen papers on sacroiliac joint anatomy, biomechanics, and dysfunction and I still don’t have an accurate grip on the matter. Some of the papers are incredibly detailed, involving 3D finite element modelling and examining stresses, stiffness, compression, shear, and load distribution in different scenarios. However, the vast majority of folks don’t need to be bothered with these sorts of things, so in this blogpost I’m going to focus on what I feel is pertinent to the readers.

What in the heck is the Sacroiliac Joint?

Here’s what Wikipedia has to say about the sacroiliac joint:

The sacroiliac joint or SI joint is the joint in the bony pelvis between the sacrum and the ilium of the pelvis, which are joined by strong ligaments. In humans, the sacrum supports the spine and is supported in turn by an ilium on each side. The joint is a strong, weight bearing synovial joint with irregular elevations and depressions that produce interlocking of the two bones. The human body has two sacroiliac joints, one on the left and one on the right, that often match each other but are highly variable from person to person.

As you can see, the SI joint is pretty damn important. We transfer huge loads through the SI joint when we lift weights, run, or play sports, so the structures that affect this joint need to be strong and fit.

Your Low Back Pain Might be Stemming from the SI Joint

This is an important take-home point for practitioners – somewhere between 13-30% of low back pain sufferers are actually experiencing pain due to sacroiliac dysfunction (Maigne et al. 1996, Schwarzer et al. 1995, Sembrano & Polly 2009).

Just how does this happen? The answer is pretty confusing. In case this is your sort of thing, then below is an excerpt from THIS paper. If this is not your cup of tea, just skip over this section.

It is widely held that a relationship exists between excessive soft tissue deformation and pain, mediated by group IIIand IV nerve fibers. Immunohistochemical staining of the articular surfaces, associated ligaments, and joint capsule suggests that, in addition to the joint itself, periarticular structures,when strained, could act as sources of pain typically ascribed to the SIJ. Spinal pain mapping studies suggest that deep somatic spinal structures including facet joints, posterior annulus, and lumbar nerve roots may refer deep, achy pain that can simulate an SIJ etiology. Immunohistochemical studies focusing on intraligamentous nerves found in SIJ ligaments lend credence to the possibility that SIJ ligaments could function as pain generators in LBP. Substance P and calcitonin gene-related peptide are both recognized as important neuropeptides in the transmission of pain. Immunohistochemical reactivity to substance P and calcitoningene-related peptide suggests that a tissue can function in pain transmission. SIJ articular cartilage, the anterior sacroiliacligament (ASL), and the interosseous sacroiliac ligament(ISL) have all demonstrated nerve fibers immunoreactive to both substance P and calcitonin gene-related peptide. In addition, the posterior SIJ ligaments have also demonstrated immunoreactivity for substance P, suggesting that both the SIJ itself, and the ligaments constraining it, could play a role in the genesis of LBP. These immunoreactive fibers likely conduct pain impulses in response to mechanical pressure or deformation.

When on One Leg You can Incur More Stress to the Structures than During Bilateral Stance

In THIS (click to download the pdf) review article, the authors stated the following:

The SIJ is 20 times more vulnerable to axial compression failure and twice as susceptible to axial torsion overloading than are the lumbar motion segments. Imbalanced or unilateral loads may jeopardize the interlocking sacral mechanics by impeding balanced transiliac bony fixation and ligamentous tension across the “keystone”. Miller et al. discovered a threefold increase in sacral rotation with both ilia fixed versus a 2- to 8-fold increase in sacral rotation upon loading with one ilia fixed. Hence, athletes and workers participating in activities requiring repetitive, unidirectional pelvic shear and/or torsional forces (e.g.,figure skaters) may have a higher propensity to develop sacroiliac joint dysfunction.

Muscle Balance

The same paper as above had this to say about restoring muscle imbalances:

Muscle balancing efforts should concentrate on the powerful two-joint muscles around the sacroiliac joint (e.g., gluteus maximus and biceps femoris) as they exert shear and torsion loads proportional to the strength of their contraction. Vleeming et al.  have documented that muscles attached to the sacrotuberous ligament (i.e., gluteus maximus and, in some individuals, biceps femoris and piriformis) can significantly limit ventral rotation (i.e., nutation). The clinical relevance of Vleeming’s work may be seen in a patient with a flexed sacrum or ventral capsular tear, tight psoas muscles, and weak gluteus/hamstrings. This individual will require correction of the imbalance to impede aberrant sacroiliac motion and loading.

A Ton of Force Transmitted through the SI Joint? That’s Not Far-Fetched!

Check out THIS (click to download the pdf) review article by Stu McGill. It was published in 1989 – which was 23 years ago! In the article he states the following on page 91 (half-way down on the left hand side):

For example, if the forces of muscles that originate in the SI region are tallied for the trial illustrated in Table 1, then the total force transmitted to the SI region during peak load exceeded 6.5 kN. Such a load would lift a small car off the ground!

When looking at table 1 on page 86, you’ll see that this data was gathered when examining a 27 kg squat lift. This is just under 60 lbs, which ain’t shit! 6.5 kN equates to 1,461 pounds of force.

If you put 1,461 pounds of force on the SI Joint when squat-lifting a 60 pound box, I wonder what kind of force we put on the SI Joint when we lift even heavier loads! It should be mentioned that squat-lifting is slightly different than squatting or deadlifting…it’s actually a mix of the two lifts but involves picking up a box placed in front of the body. Since the load isn’t centered under your COM, you receive much more spinal (and SI joint) loading due to the increased resistance moment arm.

However, I’m pretty sure I could squat-lift 300 lbs if need-be, which is 5 times greater than the load used in the study! What would the SI Joint forces be in that scenario? I’m sure it would be well-over a ton. Insane in the Membrane!

What is Needed for Optimal SI Joint Functioning?

Though the joint itself is an inherently stable structure, there are a lot of muscles and ligaments that contribute to the stability of the sacroiliac joint, and these muscles vary in terms of contribution depending on the position of the body and force vector (magnitude and direction) or loading.

In THIS (click to download the pdf) highly complicated article, it was shown that the pelvic floor and transverse abdominis helped contribute substantial stability to the SI joint from an upright standing position, indicating that these muscles need to be functioning properly to distribute forces in an optimal manner. Vleeming’s work has suggested that the erectors, thoracolumbar fascia, inferior fibers of gluteus maximus, long head of biceps femoris, transverse abdominis, and lats can affect the tension of various ligaments.

Craig Leibenson discussed the muscular slings that work together to provide support to the SI joint in THIS (click to download pdf) article.

In general, to ensure good SI joint load transfer, you need:

1. Ideal posture (lordosis, pelvic tilt, etc.)
2. Proper force closure of the SI joint (created when muscles pull on ligaments that attach to the sacrum and pull it tight against the pelvis)
3. A stable lumbar spine and pelvis characterized by (for lack of better terminology) a strong outer unit (glutes, obliques, erectors, abdominals, lats, etc.) and properly functioning inner unit (diaphragm, transverse abdominis, multifidus, pelvic floor)
4. Good hip mobility
5. Good bilateral and unilateral hip stability
6. Good motor control and kinesthetic awareness during movement (not many people are fully aware of their spinal and pelvic posture during movement)

What to do When the SI Joint Flares Up

Now to the most important part of the article. Sure, the SI joint can take a beating, but if you consistently train hard, chances are your SI joint will act up from time to time – some folks will have issues more so than others due to genetics, posture, and dysfunction. Personally, I experience SI joint issues around once per year, and when this happens I have to pull back on the reigns.

If it’s Bad, Take Time Off!

If the joint is really acting up, just take some time off and try to the best of your ability to give the SI joint some needed rest. Sure, bedrest is rarely the best option for rehab, but the SI joint is sort of like the ribs in that it’s damn-near impossible to truly rest. Anytime you’re on your feet you are transferring forces through the SI joint. If you’re on one limb, the forces increase. If you’re carrying something, the forces increase.

So definitely keep in mind that even excessive walking and having sex (especially if you’re a nasty little Wildebeest) can prolong recovery.

Don't Overlook This! It Could Prolong Your Recovery.

Don’t underestimate how much force is transferred through the SI joint during upper body and core exercises. Definitely don’t be doing any heavy deadlifting, squatting, barbell Bulgarian split squatting, farmer’s walking, Pallof pressing, or landmining.

Let pain be your guide, but know that when you start training, the juices start flowing and your body can lie to you and fool you into doing more than you should.

Ease Back into Things

When things get better, gradually ease back into heavy lifting. Don’t go overboard on the volume or the intensity right off the bat. Give yourself at least a week to transition back into heavier lifting. Maybe three progressively more intense workouts over the course of the week, followed by a couple days off.

Correct any Dysfunction

Now it’s time to address the issues that got you there in the first place so you can avoid the likelihood of reoccurrences. Corrective exercise and improved form on the various heavy strength exercises are paramount. However, it’s also important to know that SI joint pain can happen to any lifter.

You can have good posture, a sound-functioning core, strong muscles, good flexibility, and great technique, yet still experience SI joint pain from time to time. This is the nature of the beast when you’re transferring over a ton of force through the region several times per week, 52 weeks per year!

Hopefully this article is helpful to some of you folks!

I haven’t written an ABC post in a while but I’m bringing it back! Lately I’ve been getting a lot of emails asking the same thing so I’d like to address some of them here on the blog. Today’s question is from Jordan:

Hi Bret,

I am a huge fan of your blog and content, you have completely innovated the way I think about training for athletic performance.

I have been working for a while to implement the glute thrust in my training, but have encountered a problem.  My hamstrings always take over! Any suggestions on how to remedy this?  Maybe that would be a good article, as other lifters at my gym have had the same problem.

Keep up the good work!

Jordan

Hi Jordan,

Thanks for the kind words. Here are my thoughts:

1. Be Patient

It probably took a lot of time for your glutes to gradually shut down. Your body has learned to rely upon your hamstrings during hip extension. You can indeed cure this quickly, but it won’t happen overnight. It might have taken you 5 years of neglecting your glutes to get to this point, but luckily it will only take several weeks to get the glutes up to par.

2. Static Stretch the Hip Flexors First

If your hip flexors are tight, stretch them first so you can reach end range hip extension and get into the zone of maximal glute activation. Many people have tight hip flexors, but not all people do. Stretch the psoas and the rectus femoris if need-be.

It may also be wise to stretch the hip flexors for other reasons; you may be able to inhibit them a bit and create some slack to make things easier for the glutes.

3. Static Stretch the Hammies First

You may be able to inhibit the hammies a bit by stretching them prior to bridging, and this inhibition could theoretically coerce the glutes to become more active during hip extension.

4. Experiment with Pushing Through the Forefeet

Pushing through the forefeet rather than the heels could be of help. In theory it should increase quad activation and decrease hamstring activation, which would therefore require the glutes to kick in to a greater extent.

But theories don’t always pan out in the real world. Some individuals find this tip helpful while others find that it makes matters worse. When I conducted my glute seminars in New Zealand last year, I had every attendee experiment with this technique. I ended up polling over a hundred attendees regarding forefeet pressure and hamstring activation. The results? Around a third of the attendees felt that it helped reduce hamstring activity, around a third felt that it made matters worse and increased hamstring activity, and around a third couldn’t feel a difference. Give it a try and see if it works for you.

5. Focus and Visualize

Think of the brain as a lake, the spinal cord as a river, and the nerves that feed the erectors, glutes, and hamstrings as waterfalls. I realize that this is not accurate and way too simplistic but it serves as a good analogy. You want to steer more water to the glutes and less water to the erectors and hammies over time.

Focus very intently on using the glutes to push the hips upward. Research shows that intense concentration and visualization can dramatically affect motor learning and muscle activation. Over time you’ll automatically use the glutes heavily during hip extension, but you have to create these neural adaptations and increase the juice delivered to the glutes during hip extension, which may take several weeks of consistent practice.

6. Practice the Posterior Pelvic Tilt Hip Thrust (PPTHT)

The PPTHT is a great way to improve upon your mind-muscle connection to the glutes. First off, most people are incredibly week and uncoordinated with posterior pelvic tilting and lack strength, power, and endurance in this regard. A posterior pelvic tilting moment (torque) is required to prevent anterior pelvic tilt and keep the pelvis stable during heavy deadlifting so strengthening this motion is important.

Second, the inability to dissociate the pelvis from the spine is not an ideal situation and could lead to low back pain and injury especially if the individual engages in heavy or explosive activity.

Third, combining PPT’ing with hip extension requires that the glutes do two things at once which dramatically increases glute activation.

Some individuals who are flexion intolerant could find the PPTHT problematic but most people can easily tolerate it and will benefit from the added glute activation and PPT’ing skills.

Fourth, PPT’ing slackens the hamstrings which places them at suboptimal lengths, theoretically causing the glutes to have to do more to make up for the lack of hamstring force. The act of using the glutes to PPT therefore increases the glute requirements by interfering with the length-tension relationship in the hammies (it should be mentioned that the hammies may slightly contribute toward PPT’ing so this line of thinking could be more complicated).

Fifth, it takes the erectors out of the equation.

And sixth, PPT’ing can theoretically improve anterior pelvic tilt (APT) posture. I’ll expound upon this in a future article. As you can tell, I think the PPTHT is a very good thing that more people should incorporate into their routines. I’ve been employing it myself and with several clients and the consensus is that it’s very helpful and worthwhile.

To perform the PPTHT, focus on pelvic motion. You want anterior pelvic tilt at the bottom and posterior pelvic tilt up top. Squeeze the glutes forcefully and hold the contraction for 1-3 seconds up top. Here’s a video:

Hopefully you find some of these tips useful, but the most important thing is to simply concentrate and focus on using more glute and less hammy which will shift the neural tides over time.

Best of luck Jordan!

BC