Running Strong: Video Analysis, Running Re-education and Strength and Power Program for Runners

The Running

Strong Program

What is it?

A 4 session program to improve your running and decrease your chance of injury.

What is it composed of?

  • Detailed analysis of your running history and programming to find predictors of injury
  • High Speed Camera (240 frames/second) analysis of your running form
  • Pelvic Drop
  • Detailed functional evaluation of your physical function designed to find weak links
  • Custom created corrective exercise and performance based exercise program including 3 follow up sessions

Is it covered by insurance?

 

Yes.  I am both a physiotherapist and chiropractor.  Each session can be billed separately and our rates are well within the normal fees charged for regular physiotherapy sessions

The cost?

$400.00 for the initial 1 hour session plus 3 follow up sessions.

The timeframe?

The timeframe is surprisingly flexible.  Some people need a follow up session within a week of the initial evaluation.  Others might need a follow-up session within 3 weeks.  Having this flexible time frame allows us to tailor the program to your needs.

Can I work with my existing coach or personal trainer?

Absolutely.  In fact, this is encouraged.  I regularly work with running or triathlon coaches to create safer and better training programs.  If you already work with a personal trainer we can speak with your trainer about encorporating the running performance program into your existing exercise sessions.

About Me:

I am physiotherapist and chiropractor with a MSc in Exercise/Spine Biomechanics.  I have published more than 20 peer-reviewed academic papers on exercise science and injury.  I regular work with runners and multisport athletes from beginner's to Olympic athletes.  I currently write injury prevention articles for Triathlon Canada.  I am also an instructor with therunningclinic.ca - Canada's, if not the World's, leading course on the prevention and treatment of running injuries.  Last, I am the clinical director of Medcan's Run Well 3D Kinematic Analysis Program for Running Injuries.

Related Posts

1. Running Strength: Moving beyond the Core

2. Running Biomechanics: Clinical decision making in running analyses

3. Gait Modifications for Runners.

 

Form, footwear and footstrike: an e-book on running mechanics review with injury insights

This post is a link to a pdf ebook on the presentation I gave for the MSK-Plus course November 25, 2012.  Below I give a brief intro into the confusion that surrounds these topics.  If you note a huge amount of uncertainty, a whiff of grey and lack of simple answers than your interpretation is correct.

 

The pdf file is form footwear and footstrike running mechanics ebook nov20 2 2012.

Related posts

1. Barefoot running and footstrike style overview

2. Gait modifications to influence impact loading

3. Barefoot running and running economy

4. Running in the backseat: lack of hip extension and its possible relationship to injury

5. What we know and don't know about running injury prevention

Overview

We can change the following variables of running:

1. Kinematics or changing the position of the body (e.g. trying to not let your knees collapse inwards) or the timing of events (e.g number of strides per minute)

2. Footstrike style

3. Footwear: barefoot, "barefoot shoes", minimal shoes, traditional cushioned shoes with an attempt to "correct" something

We also hope that changes in mechanics will occur.  Some variables that may be related to injury:

1. Rate of impact loading

2. Joint forces

3. Muscle loading, timing or activation levels

4. Joint kinematics

 

We assume that making one change will result in positive changes in other variables. The big assumption is that we know what is bad in running.  It sounds so simple, but in practice it is not. Especially when we deal with something like pain and injury.

What you will see in the attached e book is that nothing is that simple.  Changes in many variables related to running often don't result in the "positive change" in some running variable that we hope for.

 

Below is a brief introduction to the modifiable variables and their relationship to running mechanics and to a less extent injury.  The attached pdf file goes into a little more detail.

 

Modifiable variables during running

Run barefoot or run minimal

I wish it were this simple.  We have some data suggesting that some barefoot runners will run with a forefoot strike, reduced stride length and other changes and thus they will have a decreased rate of impact loading.  We have no data suggesting that making this change reduces injury and the link between rate of impact loading and injury is a wee bit murky.  We also have a number of research studies showing that just changing to barefoot is not sufficient to result in decreases in the rate of impact loading.

In Lehman's terms, we may want to be cautious about any blanket statements

 

Lose the cushioned shoes and run in flats

I do this but I certainly don't think its the answer for everyone. I also run in cushioned shoes because I think variety is important.  As for mechanical changes when going to flats there is not a lot of robust data out there that supports this in terms of biomechanics.  The assumption is that if you lose the heel on your shoes and the cushion you will automatically start to run with a softer gait.  Again, this is not supported in the literature and research exists showing increases in rate of loading and joint loading with racing flat like shoes.  Again, we need to reserve our blanket statements.

 

Convert from a heel strike to a forefoot or midfoot

The assumption is that heel striking is bad.  Again, not strongly supported in the literature.  Research is mixed with some work showing decreases in the rate of impact loading when going to midfoot or forefoot but we also have conflicting work showing the opposite.  Again, blanket statements are not cool.  The epidemiological research is also in its infancy, is correlational in nature and correlation data sucks for implying causation.

Decreasing stride length and increasing stride rate

This modification may have the most support and may be a common variable in other interventions.  For example, I think that someone might strike the ground with a forefoot strike and have a large rate of impact loading if they have a long stride, while another individual might convert to a forefoot strike and also decrease the length of their stride.  We might initially conclude that the forefoot strike was the variable that resulted in the decrease in the rate of impact loading but really it was just having a shorter stride.  This may also be a factor with barefoot interventions.  Barefooters tend to stride shorter...maybe those barefooters with higher impact loading rates failed to decrease their stride length.  BUT, and there is always a but, we do have a well designed study that showed no changes in impact loading when increasing stride rate (Giandolini 2012).  I am not even sure how that is possible but that was their finding.

 

Kinematic variables

The ebook does not touch on this but these would be things like increased frontal plane projection angle, hip valgus, hip internal rotation, pelvic obliquity, lack of hip extension, increased anterior pelvic tilt, prolonged pronation, lack of pronation, uneven arm swing, lack of trunk rotation etc.  Surprisingly, we have very mixed data on this.  Even the biggies like increased hip internal rotation and hip valgus.  Sure there is some correlational data that shows that some runners with knee pain have greater amounts of hip valgus when compared with controls but the predictive data is much weaker.  We also have data showing no relationship between assumed gait flaws and any current injury.

We don't know if pain begets gait flaws (e.g hip weakness) or if the biomechanical flaw caused the pain.  What might surprise you is that we can often rehab a patient, get them running injury and painfree and they still present with the initial "biomechanical flaw".  My concern with assuming that some biomechanical variables are faulty is that this views the body as being inherently weak and we forget about its amazing variability and strength.  You will see lots of runners with huge amounts of hip valgus/knee collapse.  You will shudder in horror at this.  But sometimes that is just that person's little idiosyncrasy .  They have always done it and they have adapted.  You will try to fix them under the assumption that they are faulty.  But this a massive assumption.

I am working on a large post on the kinematics of gait and injury.  I will go into a lot of detail on this topic

 

OK.  So everything is grey.  What do I do?

 Warning: Opinions ahead.

Gait modifications can help with an individual in pain:  We have good data that a slow return to running with modifications to form can help.  I don't necessarily believe that this is always related to biomechanics in the sense that we are changing mechanics to be closer to an ideal.  I think we are changing mechanics and it is the act of change that is important.  Variability and novelty is important to me in all my rehab programs.  Changing your gait loads the body differently and is also different for the brain.  Different gait patterns may avoid certain physical stressors on the body and may not activate our pain neurotags because of the novelty.  Further, most gait re-training is a slow, gradual return to running.  This exploits our innate adaptive abilities.

 

How should people run if not in pain?

Please note, the suggestions below only relate to running form.  There are a lot of things we can do to reduce the risk of injury.  Below is not comprehensive.

If I have to go out on limb I would suggest four things:

1. Novelty and variety: different shoes, different surfaces, different speeds, different distances.

2. Check your cadence: if you are running a five minute kilometer than  your steps per minute should be greater than 170 per minute.  If  you are "loping" and don't have a quick turnover consider increasing your cadence.  What you are trying to avoid is landing with the foot extremely far in front of the body and this is associated with a close to straight knee at footstrike

3.   With reservation and many exceptions, a midfoot to forefoot strike with the occasional heel strike thrown in:  this one is tough for me to say and I have some hesitancy. If you are novice runner I would probably suggest running with a midfoot strike. I think the bulk of the research suggests that running with a midfoot strike is the way to go.  I know that there is research suggesting heel striking is fine especially if it is not associated with overstriding.  I totally get this.   As  I said, I have some hesitancy - I treat a lot of heelstriking runners and would not consider changing their gait so this suggestion is obviously not a blanket for everyone.  Many heelstrikers have their feet land close to their body and their gait is soft and quick. However,  I also think that thinking about midfoot striking will also help with your cadence.  Last, for slower runners (10 minute miles) I doubt footstrike matters as much.  One caveat, I also think many runners would benefit from using different footstrikes during the same run provided their cadence is not too low.  This is consistent with my views on variety.

4. Gradual increase in running or in changes in form.  This one is obvious.  The body adapts over time we just have to give it some time to adapt.

 

My bottom line

I would be hesitant to change things about someone's form if they have no injury or past history.  If they have had a series of past injuries or currently have an injury this is where I think we can help the most with changes in form.  What you will see in the e-book is that there are so many exceptions to our commonly held beliefs about certain running related variables.  These exceptions make me quite cautious in just trying to change runner's form when you don't actually know what you are causing when you try to make a change.  I am lucky in that I have access to 3D motion capture equipment.  I can see what happens with different changes in form.  But I don't have force plates and I can make no comment on changes in joint loading or impact loading.  And the "running expert physio" dude with one camera (or who just eyeballs a runner from behind) can't say what changes in force (e.g rate of impact loading are occurring) and is also probably wrong about a runner's kinematics should be a little cautious in just making changes based on one or two cherry picked research papers.  What the research in this e-book shows is that many changes we assume to be good end up resulting in elevated levels of impact loading or joint loading.  Thus, I advise caution.

 
 
 
 

 

 

 

What is a functional exercise for runners and athletes?

clamshell open
clamshell open

A recent discussion was sparked by Mike Reinold's thoughts on the Clamshell exercise. I found myself defending the lowly clamshell exercise for runners. I was discussing with other physios whether the clamshell exercise was less "functional" than a band walk exercise (where you put elastic bands around your knees/ankles and walk forwards, sideways or backwards).  I suggested that both were NOT (or equally) functional but agreed that both had their uses. I can tell  you, I convinced no one :)

The consensus against me was that the clamshell sucked and that the band walk exercise was superior.  I tried to argue that this might be true but  not because the Bandwalk was more functional.  We essentially just babbled back and forth with no resolution for 20 minutes. The problem was the word "functional".

What the hell do you mean by 'functional".

When I heard someone say the bandwalk exercise was more "functional" than the clamshell I immediately thought malarky.  Because my knee jerk reaction to hearing "functional" was my brain translating this to "movement specificity" or kinematic specificity.  Meaning the exercise you are training matches the kinematics (specifically the displacements or joint angle motion) of the athletic task (in this case running).

Using kinematic/movement specificity to judge a Bandwalk or a Clamshell was a no brainer.  In terms of function (using the kinematic specificity definition) they both suck.  No runner lies on their side and lifts their leg up (e.g. the clamshell) but no runner runs sideways with a bloody elastic band around their knees.

So lets define "functional"

My knee jerk translation of "functional" to being "kinematically specific" is a little narrow. Our discussion exposed this.  Function to me means that the exercise has some sort of relevance to the task the athlete hopes to accomplish.  Viewing it this way then exercises can be functional or relevant thru a number of different means:

1. Movement specific: this means the exercise task somehow looks like the athletic task it is trying to train.  This means your exercise has similar form (due to motor control) to the goal task.  Further more, it suggests that the neuromuscular recruitment pattern is similar to the exercises (e.g. muscle onsets, offsets, ratios etc) For example, squats are great functional exercise to get out of a chair.

2. Muscle or joint specific: this means the exercise is training similar muscles to the muscles that are being used in the goal task.

3. Velocity specific: this means if your goal task requires you to move fast than you should probably train fast.  Exercises are therefore "functional" if they lead to some sort of carryover to the goal task's speed demands.  We know that you don't actually have to move fast to get this carryover, sometimes just the intention to move fast will garner improvement

4. Movement direction:  if your goal task requires a lot of deceleration than you should probably train the eccentric loading capability during your exercise.  For a runner, you might think they have increased hip adduction during the impact phase of  running which occurs for less than 100 milliseconds.  Thus you should probably train this deceleration ability over that specific time frame for it to be functional.

5. Context: the exercise should be similar to the context of the goal task.  The context might the exercises relationship to gravity or even to a societal or performance context (e.g you train to shoot free throws while people are screaming at you).

So what is more functional the lowly clamshell or Bandwalks?

Trick question! You can't answer this.  There is no functional scoresheet.  The better question is what is more useful to the runner or athlete.   You have to be able to answer why  you are prescribing an exercise in the first place. What is your intention with each exercise? What do you hope to accomplish?  If you prescribe an exercise because it is "functional' than this is just begging the question. Functional isn't enough it has to lead to some specific gain.  And if you think it is functional why is it beneficial?

A case example in the limits of functional justification: The BandWalk

I think most people would argue that the Bandwalk is more "functional" for the runner because it appears to train the muscles used in running in a more similar manner kinematically and more of the muscles that a runner uses when they are running.

But does it really do this?  How much of the previous "functional" components does the band walk satisfy?

Movement Specificity: No runner runs with a band around their knee, they don't run sideways or backwards. On its surface it certainly isn't very similar in terms of joint angles and displacements.  If you think movement specificity is important or practice makes perfect than training a movement that is so dissimilar to running can't be justified in this manner.

Movement Direction: Lateral band walks do not train the hip abductors in the manner that they are used during running.  Eccentric control occurs over very short period under high impact loads when running.  Band walks are extremely dissimilar to this. They are slow. They have an external force that is extremely different to the force vectors that create joint torques during running.  We don't satisfy a movement specificity or even a velocity specificity argument.  Considering this is the Bandwalk still functional?

Context? The band walk looks better than the clamshell that is for sure.  The athlete is standing and shifting weight.  But are they standing a shifting weight like a runner shifts weight? Nope. Is just standing and having weight shift enough to make it functional?  Why not do dumbbell curls while standing and shift your weight back and forth.

Motor Control:  No way.  Doing bandwalks are nothing like the motor patterns used in running.  Timing would be way off, no impact, no feedforward activation of muscles to damp vibration, hardly any storage of elastic energy.  Do you think the "extensor paradox" occurs during a band walk.  Not a chance.  These two tasks are completely separate beasts.  There is no way you can argue you are engraining some motor pattern during the band walk to enhance running.

Is the BandWalk Garbage?

Nope.  It can certainly help runners.  I don't use it but I still think it is reasonable for a runner to train with it. Because it satisfies our simplest category of "function".  It trains a group of muscles that runners need.  These exercises build the capacity of those muscles and this probably transfers over to increased mechanical efficiency and maybe even some injury protection. However,  if you think that it is functional enough to actually change a runners form than you might end up getting some poor results.

The problem with this last justification for strength coaches and rehab people is that it is too simple.  As therapists we want to think that we have some special knowledge about special exercises.  We don't.  There are no special exercises.  Train hard, train smart, get strong, build power, build tolerance, build capacity, build endurance, build the ability to absorb load, dampen vibration, produce strength at all ranges etc.  Have a generalized, good all around program and you will probably have good results. Maybe through in some assessments to see where your athlete is lacking and then train the hell out of that and you will do better. But, there are no running exercises.  And that is what both the research suggests and gurus suggest.  Pick an expert in a field of strength and conditioning (powerlifting, olympic lifts, corrective exercise, pilates, yoga, core stabilizinationists etc) and they all swear by their success with runners.   They are all probably right.

OK, so is the clamshell better?

No way! The clamshell sucks most of the time.  I got started blogging a lot because of Mike Reinold's post on a research study in JOSPT that looked at EMG in the hip abductors. The clamshell was a touted exercise and  I hated it. I thought runners should never do it.  I thought it was remedial and "non-functional".  My comment is on Mike's site.

The clamshell works fewer muscles, has the person lying down, looks kinematically different than running and doesn't satisfy many of the functional principles I laid out earlier.  BUT, it does train some muscles substantially different than the bandwalk.  This is where it can be a useful exercise.

The clamshell sees the hip flex to 90 degrees and has the patient externally rotate the hip.  At 90 degrees, because of changes in the line of pull of many hip muscles (GMax, GMed, Piriformis) the only muscles that externally rotate the hip are the deep external rotators.  So training the capacity of these muscles might carryover to running.

I used to abhor the clamshell.  Then I started testing more runners with the clamshell. A number who tested strong in many positions would tremble during the clamshell.  Crazy, they had a lovely one leg squat, strong hip abduction but had trouble with 10 or 15 clamshells.  What does that tell me?  Such a massive deficit in function.  Would you suggest clamshells here or something to address that specific movement?  This seems like a case where I would suggest clamshells.  If a runner can't do them I would want to address that deficit.

But, do I want to see every runner doing them as part of a "functional" program. Of course not.  They suck for that.  This is a case a where the exercise prescription is "functional" because it addresses a specific limitation in a specific runner.

OK. What do you suggest?

I have no exercise that addresses all of the components of "Functional" but that's why runners should get a comprehensive program. If I have a bias I lean to training "Comprehensive Capacity".  This means you train runners like they are athletes.  Big multijoint-compound exercises that train strength, high load power (e.g cleans), low-load power (ploymetrics), variable range exercises and unilateral exercises.  The thing with the word "functional" is that is so broad to be meaningless to justify an exercise.  Choose exercises based on some other specific capability of the neuromuscular system you hope to improve.

The Key Question: Why are you training what you are training?

For runners, I only think that we are training the muscle, joint, tendon and nervous system's capacity to tolerate stress that running imposes.  This makes runners more powerful, mechanical efficient and may make them less injury prone although with hip abductor training the research is a bit dodgy.

Do exercises help change running form?

This is seems to be the underlying idea behind an exercise that kind of looks like running (eg. the clamshell).  That training in that manner will improve your running form.  But there is some evidence to suggest that this does not occur (Willy 2011). We probably aren't training form.  We aren't correcting the biomechanics of running by choosing certain exercises.  We aren't engraining some motor programs that carryover to running.  If you want to do any of these things you have to do that while running and with some form of feedback.  Our bodies are not puppets where muscles can be tightened or loosened to obtain some different posture or form. That is a motor control skill not something that changes with other exercises.

So why are you prescribing the exercises you prescribe for your runners?

Please let me know what other rationales are out there.  I don't think this brief article really addresses everything

Greg

PS

This discussion was also quite serendipitous.  I was just finishing a pictorial post of bunch of hip exercises that people can use for their patients.  The pictures are all high quality and the idea is that you download them and put them into handouts or your website and what not.

Hip Centricity: A pictorial of hip exercises

 Related Posts:

1. The relationship between functional tests and athletic performance: Part I – The single leg balance test.

2. Can we treat our patients like puppets? Changing posture through exercise?

3. Running Injury Prevention: What we know and more of what we don't

4. Runner's Strength: Some simple exercise videos for runners.

Running in the Backseat: A rationale for improving hip extension in runners

Poor hip extension is a favourite of boogeyman for all manner of back and leg injuries. I have reservations about its relevance to pain and injury in terms of how the hip flexors get tight and the relevance of regional interdependence to pain (see here and here). Yet, I do not completely ignore the possibility that hip extension limitations (or not using your available hip extension) can influence function...I just think its over-rated and over used. One area that limited hip extension is proposed to influence function is during gait.  Dr. Howie Dananberg has detailed this in his theoretical ideas about how functional hallux limitus (lack of big toe dorsiflexion) leads to lack of hip extension, which in turn causes a decrease in the stretch of the psoas, leading to the loss of passive muscle recoil (because no psoas stretch) to initiate leg swing during gait and and ultimately increases in stress on the lumbar spine that leads to pain. (see a review here and one from me here).  Another theory regarding running has been championed by Jay Dicharry which is slightly different and puts a strong emphasis on performance as well as the possibility of pain.

Jay Dicharry is a biomechanics researcher and physical therapist with a focus on running injuries.  He runs a gait biomechanics lab at the University of Virginia (blog here) and has published some excellent reviews (here) and original research in the area (here).  He has also a new book out on running injuries (here).  I am a big fan of how Jay explains running biomechanics and he does an excellent job in his book. In the book he proposes a possible mechanism where lack of hip extension may negatively influence runners.  Jay lays out an excellent case for how poor hip extension can compromise efficiency (I can get behind this) and may also increase injury risk (I'm still skeptical when anything comes to pain because of the complexity of the pain experience and the poor track record that biomechanics has in predicting pain but this is no fault of Jay Dicharry).

Theory in a Simplified Nutshell:  Limited Hip Extension causes Overstriding.

Jay describes the swinging leg as pendulum.  It has a front side swing (swinging forward to strike the ground) and a back side swing (backside mechanics that occur before the leg leaves the ground).  What Jay suggests is that if you don't have adequate hip extension the athlete will "sit back" while running and will have increased front side swing (see the picture above from www.goodguystri.ca).  In other words, the pendulum arc will be shifted to the front side and the runner will land with the foot too far in front of the centre of mass - aka: overstriding.  This problem will be compounded at increasing speeds when the athlete looks to increase their  stride length.

Jay suggests that running in the back seat leads to two things:

  • Increased metabolic cost associated with overstriding
  • Increased impact loading associated with overstriding

Lets look at these two in detail.

1. Increased Metabolic cost associated with overstriding

Two mechanisms may be at a play here:

a. Lack of hip extension loses passive energy return.   The muscle-tendon unit can be viewed as springs.  We use the passive energy that they store rather than merely actively contracting them.  The tendons store energy during impact (e.g. they start to stretch) and then they release that energy during the push off phase.  With limited hip extension it is suggested that the pendulum can not swing backwards past the dashed vertical line and the pendulum must then swing forward excessively.  Without the ability to swing backwards the runner doesn't have the time to release the energy that they stored during impact because they are not able to let their leg swing backwards.  

 

 

b.  Overstriding is inefficient and costs more muscular work.  When overstriding the center of mass of the runner increases its up and down motion.  This means we work harder to decelerate the mass during impact and absorption and then we work harder to accelerate the mass during the push off phase of running.  Further, with the ground striking leg being farther away from the body we are at a mechanical disadvantage for absorbing this energy.  Overstriding would then increase the load on the knee and may therefore predispose individuals to knee pain.

 

2. Increased impact loading associated with overstriding

                                            This one we have heard a lot and is the thrust behind shortening peoples strides, changing foot strike pattern, going barefoot or running in minimal shoes all in an attempt to decrease the rate of impact loading, collision force and joint loading when running.  The closer the foot is to the center of gravity at foot strike the less rate of loading and joint loads we can expect.  Heiderscheit (2011) published a recent paper showing  how manipulating stride length (decreasing it) can decrease ground reaction forces, braking forces and joint loading.  This is also the impetus behind Lieberman's work championing barefoot running - he contends that the combination of a forefoot strike and a foot strike closer to the body (i.e. what occurs with shorter strides which is proposed to  naturally occur when you run barefoot) decreases impact loading (a large review can be seen here).

 

Other kinematic consequences of limited hip extension

Not all runners with limited hip extension will end up "sitting in the backseat".  Some can increase their backside mechanics (the range of the leg swing backwards) by arching their back.  This is a common explanation we hear for the dangers of limited hip extension in runners and in all athletes or low back pain sufferers in general. In other words, if you don't have hip mobility you steal it from somewhere else (e.g. regional interdependence).  In this instance you get the range from your spine. Many authors have speculated that this increases ones risk for low back pain and for hamstring strains but again the data is not there.  However, if you are  having aches and pain with running this may be one area you could modify to modulate your pain response. Sometimes getting out of pain is just changing a habit, providing something new and different to our body (and brain) and you can feel less pain.

Critique and Comments

What I like about Jay Dicharry's opinions in this areas is that he has access to data and equipment that can support his views.  He is fortunate to have an impressive biomechanics laboratory and he mixes his clinical wisdom with the data is he is able to collect.  Questions/ideas that this theory presents to me are:

- how regularly does a reduction in hip extension lead to overstriding? Is it really the loss of hip extension that causes overstriding or are there other variables.

-if the pendulum arc is shifted forward this implies to me that there should still be enough time for the leg to load and store elastic energy because we haven't shortened the arc just shifted it forward with the overstride.  I could see how there is less time to load and store elastic energy if the actual foot contact time was reduced because of the necessity to take a shorter stride.

-this is still an unpublished hypothesis.  Like all theories of injury or performance it does need to go through rigorous testing.  I look forward to seeing these concepts tested and published.

-the vast majority of people (more than 90%) probably run slower than an 8 minute mile (5 minute kilometer). Strides are typically small and there is a plenty of ground contact time. With plenty of ground contact time the athlete would be able to release that energy.  With less speed there is less impact loading in general and this would provide a buffer for the slight increase in loading with the overstriding. I would question how relevant this is to contributing to injury - the simple biomechanical idea of increases loads being associated with injury is not well supported.  It is not a direct relationship.  In a runner with limited hip extension I would assume they have always had limited hip extension and this would have given them a lifetime to adapt.  Lots of individuals run with greater impact loads and joint loading (even at the same speed) and they may not be more prone to injury - this is even what happens when we age (see a quick review here)

 

-I don't doubt that people might show up with pain in their knees and also run while sitting in the back seat.  I also don't doubt that changing how they run (or stretching their hips) might be correlated with a decrease in pain.  Seeing these correlations often lead us to thinking that it is the biomechanics that cause the pain when it can be many other factors.  Last, even the act of changing the biomechanics can result in a resolution of pain but not because you changed the biomechanics.  It can merely be the act of change, setting a new contest for running, doing a relatively novel and what is assumed to be a threat free way to run that can result in less pain.

-with respect to Performance I have little say.  This is the most intriguing aspect to me.  I would love to see some research showing improvements in running economy following increases in hip extension.  Jay has laid out an excellent argument for how this style of gait is inefficient.  This is certainly something worth tinkering with in athletes who are pushing their limits.

 

 

The relationship between functional tests and athletic performance: Part I - The single leg balance test.

Background: Testing and assessing an individual is popular.  There is an old saying that if you aren't assessing than you are guessing.  The assumption here is that the tests and assessments you do are somehow relevant and meaningful yet I would suggest that the majority of tests and the information gleaned from them hardly change (10% ish) a therapeutic approach once you have heard your patients history. I can have a patient with knee pain and run them through 30 different tests and the results of those tests may hardly change my treatment.  Tests have to provide us meaningful information that we can do something with.What the hell am I talking about?

This blog post is the first of what I hope to be many posts that review the research on our physical tests of purported function.  We make a lot of assumptions about the tests that we commonly use in the clinic.  For example, someone might tell you that your hamstrings or psoas muscles is tight and this will cause you to be hyperlordotic (pelvic anterior tilt) during running.  Or you might hear that you suck at doing a squat and without being able to squat your form during other activities will suffer.  Ultimately, "failing" these tests can lead to you spending time doing lots of "corrective exercise" to fix a test.  This fix is assumed to help with function in other realms of activity.  I want to explore the assumptions behind the tests we use and then the purported fixes that follow.   Some of the topics I might explore:

- assessing tightness in a runner and whether or interventions influence running form

-  how strength training influences joint biomechanics/dynamic form

- how tests of static function relate to dynamic form (e.g. running)

- how simple dynamic tests (e.g. a squat) relate to dynamic form/joint biomechanics

- how measures of joint strength or ROM relate to dynamic form/joint biomechanics

- whether dynamic tests (e.g. a single leg squat) actually give insight into what they are supposed to be giving insight into (e.g. pelvic stability, hip abductor strength and a surrogate for hip control when running etc).

I have touched on these ideas in a number of other posts below:

- specificity of movement training (looks at our ability to change posture) (link here)

- the inability of tests to identify functional hallus limitis  (link here)

- weakness of the prone hip extension (Janda) test. (link here)

So here goes with a look at a common test for runners...

The Standing on one leg balance test is not a relevant test for Runners

Whoa, quick disclaimer.  This first post is an opinion as there is no evidence that specifically looks at this.  However, there is plausibility and I want to make the argument that being able to balance on one leg has nothing to do with the act of running.  This is a common test advocated by rehab professionals (many of whom I greatly respect and one has good book out on running biomechanics and injury here) looking to screen for deficits in function that are assumed to affect ideal running.  But I just don't see it.  It makes no sense to me so if you are reading this and think I am wrong please let me know.

The one leg balance test has you simply balancing on one leg with your eyes open or closed.   If you can't do it the assumption holds that you will be prone to injuries during running or you  may end up with some sort of issues with your running form.  The test is based on the idea that running is merely a succession of leaps through the air interspersed with balancing on one leg until the next leap.  I would respectfully suggest not.  Here is my reasoning:

1. The skill of running is completely different from the skill of one legged balancing. Running is not balancing on one leg as you are not static like you are during the balance test.  These two tasks are completely different. And we should not expect that one can be a surrogate for the other and reflects the same demands.  Our ability to balance is activity and context dependent.  I don't think we can assume that balancing skill in one task will carryover to another completely different task.  The same holds true for that crazy dead fad of doing squats on BOSUs or balance balls with the assumption that training this form of balance will carryover to the balance needs of a golfer or hockey player.  The latter is from Mars and the former is from Uranus.

                                                                   2. Static versus Dynamic Analogy

Running is dynamic.  You do not pause and balance on one leg.  Comparing one leg balance to running is like comparing the ability of a stationary top to balance on its point with the ability of a SPINNING top to balance on its point.  Suggesting that we need to be able to balance on one leg in order to run safely is like arguing that in order to ride a bike properly you have to be able to hop on the bike, clip in and then balance in place without moving.  I have been having my five year old do this for months before I will let her ride her bike and surprisingly she still can't ride a bike...and that bruised little monkey hates me for it.  (Obvious disclaimer: I am kidding).  But this example illustrates my point.  If it seems absurd on a bike then it is just as absurd on your feet.

Caveat of Ignorance

I reserve the right to change my opinion with new research or with fresh ideas.  I can also be convinced to think otherwise.  My mind is not as closed as my writing might indicate.  As a further hedge I also recognize that it is possible that some cross sectional study might come out and suggest that one leg balance is compromised in runners with knee/ankle/back/hip pain.  I don't doubt a correlation might exist BUT this does not imply that the decrease in balance ability is the cause of the pain.  This can merely be correlation.

Last, this does not mean that one leg balance training can not be beneficial for runners in preventing injuries or improving performance.  The act of doing one leg squats, one leg hops, hip airplanes, front scales and other great exercises could certainly improve your balance and would also change other aspects of muscle function.  In this case the improvements in balance could be secondary to other aspects of improved function that are the true drivers of improvement in performance and injury resilience.

Last point, honest- perhaps we over assess and our assessments change nothing in practice

What I think can be argued with this assessment test (along with many other tests) is that it just isn't necessary and is plausibly not valid.  If I am working with a runner or an athlete their conditioning program would be all encompassing and comprehensive.  This would include exercises that ultimately improve their balance along with other variables.  I don't need a rudimentary test to tell me to add these exercises.  I just need that human in front of me that tells me that they want to run and be an athlete.  I don't want to freak them out because of their shitty balance or advise against doing these wonderful exercises because they have great balance during a static, albeit not relevant to running test.

Barefoot running and running economy

Purpose: summarize three recent papers looking at the running economy of running barefoot Three recent papers have been published looking at barefoot, vibrams, minimal shoes and cushioned running shoes and their associated running economy (i.e. energy cost associated with running at a specific speed).

The research is a bit murky.  Those arguing in favour of barefoot or minimalist running suggest that this method of running is more efficient for two basic reasons:

1. there is less mass and therefore less work required to move the foot (older research here)

2. barefoot running allows the passive structures of the foot and calf to store and release passive energy

So what does the recent research say?

Here are the papers I will briefly review and as a spoiler I have quoted their conclusions directly in case you have somewhere else to be.

Perl et al (2012) - abstract here.

Minimally shod runners are modestly but significantly more economical than traditionally shod runners regardless of strike type, after controlling for shoe mass and stride frequency. The likely cause of this difference is more elastic energy storage and release in the lower extremity during minimal shoe running

Franz JR et al (2012) - abstract here.

Running barefoot offers no metabolic advantage over running in lightweight, cushioned shoes

Hansen et al (2011) - abstract here.

It was concluded that at 70% of vVO (2)max pace, barefoot running is more economical than running shod, both overground and on a treadmill.

So it looks like barefoot running is significantly more efficient than cushioned shoes in two studies but one study suggest that it isn't. Here is a more detailed look at each study.

Study #1: Perl et al (2012) Barefoot(Vibrams) versus bulky, cushioned shoes

Main Finding: running barefoot/vibrams (even if you add weight to your feet that is the same as shoes) is more efficient than running with shoes.

This is a great and very comprehensive paper of Perl et al (2012). I will only focus on the running efficiency aspect of the paper but the paper explores kinematics and kinetics as well.

The authors investigated four trials of running.  They used Vibrams as a surrogate for barefoot and called these minimal shoes. They investigated four trials of running:

  1. FFS in minimal shoes and ankle weights
  2. FFS in standard shoes (Asics Cumulous 349 grams)
  3. RFS in minimal shoes and ankle weights
  4. RFS in standard shoes.

The authors controlled for a number of variables that might effect economy:

  1. shoe mass
  2. foot strike
  3. running cadence (around 186 steps per minute)

They  measured or calculated:

  1. The oxygen cost associated with running
  2. Joint kinematics and kinetics
  3. Arch strain and Achilles strain (from kinematic and kinetic data)

Each trial lasted a minimum of five minutes, with at least one minute of running after VO2 levels reached steady state. A metronome was used to keep the runner at his/her preferred stride frequency

Results

  1. No difference in running economy when comparing foot strike style regardless of the shoes.  This is huge.  it argues that running technique in terms of landing does not influence how efficient we are.  But remember, this says nothing about INJURY.
  2. Minimal shoes (Vibrams) were more economical no matter what foot strike pattern.  If running with a rearfoot pattern they were 2.41% more economical and if running with a forefoot pattern they were 3.32% more economical
  3. Most subjects were economical when running minimally but a huge range was observed.  One individual was 9.6% more economical but one fellow was 7.32% more costly.
  4. Barefoot runners do not bend their knees more - there is not an energy cost associated associated with cushioning.  This is often suggested but not supported.

Important Things to Remember

  1. These authors added mass to the minimal shoes (Vibrams) so we can expect that without adding mass the minimal shoes would be even more economical
  2. All runners were experienced barefoot runners and comfortable heel or forefoot striking.
  3. Cadence was controlled – very important
  4. We don’t know how other minimal shoes (e.g. racing flats) would compare.  Is there something special about Vibrams that allow one to run as if barefoot or is this something shitty about running in standard cushioned running shoes.  The next studies look at that.  Kind of.

Study #2: Hansen et al  

Main finding: In mostly inexperienced barefoot runners individuals who ran barefoot both on a treadmill and on track had better running economy than while running in shoes.

Study Set Up

- 10 healthy runners (two experienced barefooters)

- ran on a treadmill and on track at a pace comparable to 70% of VO2 max while running completely barefoot and while running in shoes (therefore 4 runs in total)

- track running speed was assessed with the Nike+ accelerometer

- no information on what running shoes were used

- no controls for shoe mass, foot strike pattern or cadence

Results

1. On the treadmill there was no statistically significant difference in oxygen cost when running in shoes or in barefeet

2. When running on the track running barefoot showed a trend  to being more economical (Vo2 was 5.7% greater when shod - a huge difference compared to previous studies)

3. When the two barefoot conditions were combined (treadmill and track) and compared with the two running shoe conditions barefoot running was 3.8% more economical.

4. Rating of perceived exertion was consistently higher in shoes than barefoot

5. Heart rate was higher in shoes than barefoot on the treadmill only.

Comments/Limitations

The thrust of this paper is that running barefoot outside is more economical than running in big, bulky shoes.  This is interesting since this is where races occur.  However, a few limitations of this study when added together may seriously jeopardize this conclusion. Roger Kram and Jason Franz, the authors of the next study wrote an insightful letter to the editor suggesting that a systematic error in how running velocity was calculated would lead the authors to conclude that barefoot running is more economical when it is not.  Thus, the barefoot runners ran slower than the shod runners and therefore consumed less oxygen. Let me lay out their argument:

1. Velocity was measured with the Nike+ accelerometer.  It does this by knowing when the foot first strikes the ground and then leaves the ground (contact time) relative to how fast the foot moves horizontally during that time period.

2. The Nike+ assumes that you run with the same foot contact time when you are running to calculate your speed.

3.  If the device was calibrated when wearing shoes we might have a case where the foot contact time is different in shoes than during barefoot (this was seen in a study by Squadronne).

4. Kram suggests that barefoot running has a shorter foot contact time  therefore there is a bias in how the Nike+ reported the speed to the runner that was running.

5. With a shorter contact time during barefoot running the Nike+ would give an overestimated speed during running.  Therefore, barefoot runners would have run slower than their counterparts thus the changes in VO2 seen in barefoot running versus shod are due to running slower not because of the shoes.

Study #3: Franz et al (2012)  barefoot versus minimal shoes (Nike Mayflys)

This study has been blogged about previously here and here.

Main Finding: Barefoot running is not more economical than running with a light weight trainer even though there is less mass with barefoot running.

This great study looked at the oxygen cost while running barefoot (not with Vibrams but while wearing a thin sock) and in a minimal cushioned running shoe (the Nike Mayfly 150 grams).  The authors also controlled for a number of variables:

1. Barefoot running experience (all were experienced)

2. Foot strike pattern (all used a midfoot strike)

3. Mass (lead strips were added to the barefoot condition and to the running shoe condition

4. Cadence was not controlled

Study Set up

Subjects ran barefoot and at multiples of the weight of their shoe (1x, 2x and 3x the weight).  They also ran in the shoe with multiples of the weight added to their shoe.  While running at a constant speed of 3.35 meters/second (about a 5 minute kilometre or 8 minute mile) the subject's VO2 was calculated.

Results

Directly from the study:

Without added mass, the mean and gross metabolic power were both 2.1% lower when running in shoes compared to barefoot (BF0M vs. SH1M), but these differences were not statistically significant (p=0.092 and 0.118, respectively).

For eight of the twelve participants, running in the lightweight, cushioned shoes was less metabolically demanding than running barefoot, despite the greater mass.

Subjects selected 3.3% longer stride lengths during shod running. Importantly, the longer strides adopted when running in shoes reflected an effect of footwear and not of added mass; stride length did not significantly differ between BF0M and BF1M (p=0.342).

Main Points

1. Adding 100 grams of mass increases energy costs 1%

2. Barefoot running (with socks) is not more efficient versus light weight trainers despite the weight of the shoes.

3. Runners decreased their cadence and increased their stride length 3.3% in shoes

4. When running barefoot with added mass equal to the mass of the shoes the runners used 3-4% more oxygen when compared to running in shoes.

5. The authors suggest that running barefoot "costs" more oxygen because of the need to provide cushioning (e.g. more knee or hip flexion).  However, the authors did not measure this and the kinematic data from the Perl study above suggests the exact opposite of this.  In that study, running barefoot (in Vibrams) lead to less knee flexion (e.g. cushioning) when running.

Why do we have different results across studies?

Shitballs, I really don't know for sure.  But lets look at some ideas and differences between the studies.

First, the Hanson paper may be limited due to the means of measuring velocity in overground running and it does not provide much more insight than any of the previous studies in the past decade have so will limit the discussion to the Perl study and the Franz study.

The two great studies by Perl et al (2011) and Franz et al (2012) make two seemingly opposite conclusions.  Both of these studies also controlled for many of the same variables with the exception of the Franz study which did not control for running cadence.  However, there were differences between the two studies and a number of uncertainties.  Those being:

1. The Perl study compared Vibrams versus a large cushioned shoe that weighs 349 grams.  They concluded that even adding weight to the Vibrams to equal 349 grams the Vibrams were still more efficient (3% more O2 cost in the big shoes)

2. The Franz study compared barefoot (socks) running to running in minimalist shoes (shoes that had a sole but a limited upper).  These authors found that even when the weight of the shoes equaled the barefoot condition with weight added shoes were always more economical (3-4% more O2 cost in barefoot).

3. The Franz study did not control for cadence and runners in shoes increased their stride length on average 3.3%.

4. We can't conclude that barefoot runners in the Franz study bent their knees and hips more (e.g. the cost of cushioning).  The authors did not measure this and the Perl study suggests that this does not happen.

5. We don't know how minimal shoes (e.g racing flats or the shoes used in the Franz study) compare with big, bulky cushioned shoes (e.g the ones used in the Perl study).  We also don't know how running in Vibrams compares with running in socks although a previous study (Squadrone link here, although they made this conclusion in the discussion but there was no data in the results about this) suggests that Vibrams may be more efficient than barefoot alone.

Some thoughts...

It may be possible that running in Vibrams confers greater energy efficiency than running in barefeet alone  and that this could be similar to the greater efficiency achieved in the lightweight trainers (e.g. the Nike Mayflys studied by Franz) versus running in socks.  These conflicting results may not be conflicting at all since they did not measure exactly the same thing. It would interesting to know two things:

1. What is the difference between running in the Mayflys (lightweight trainers) and big, bulky shoes (i.e. the shoes used in the Perl study that compared Vibrams with shoes)

2. What is the difference between running in Vibrams and running in the socks that the Franz studied compared the Mayflys with.

The implication for these questions is whether it is plausible that running lightweight running shoes (the Mayflys at 149 grams) is similar to running in Vibrams (149 grams).  If these two footwear choices are comparable then we don't have any discrepancy between the studies.  It suggests that light weight footwear (Nike Mayfly or Vibrams) is more efficient than barefoot/socks even when the weight of the shoes are controlled for (i.e. the conclusion of the Franz study) and that Lightweight footwear is more efficient than big, bulky shoes even with the weight of the shoes are controlled for (i.e. the conclusion of the Perl study).

Implications

1.  The Franz study certainly argues in favour of running in light weight trainers.  It suggests that you get many of the benefits of barefoot running without the drawbacks of the added weight associated with the large cushioned shoe.

2.  The Franz study also suggests that we don't always have to shorten our stride to get efficiency.  This is sometimes advocated but the study suggests that a longer stride is associated with improved efficiency when wearing shoes.  This is not new and was the conclusions of Cavagna's research for years (sample abstract here) when he looked at preferred stride frequency.  He basically suggested that the body finds the stride frequency that is most efficient for it.  Sounds simple.  The body seems to have some inherent wisdom.

3. We have no idea what happens after running for 90 minutes.  This is what I am interested in.  I think the arguments for barefoot running and performance can really break down when it comes to running at extremes of fatigue.  We see this anecdotally with barefoot runners starting to heel strike at the end of races.  The cushioning cost has to come from somewhere and I would rather this have been something passive (like my shoe) than something that can fail and fatigue (e.g. arch strain, achilles tendon etc).

Case Study: Unexplained dead leg when running. Altered nerve tension?

Purpose: Demonstrate a case of an altered nerve tension in a runner that may be exacerbated by their running technique. Case Details

Female, late twenties, competitive runner (sub 20 minute 5km, 1:30 half marathon, 3:15 full marathon)

Symptoms

- 2 year history of left lateral lower leg pain that comes on with running

- begins around 20-30 minutes into a run and often feels like she can't control her leg with a sense of numbness (like she might fall)

- but no obvious swelling, shininess or pain in the anterior compartment during these bouts

Select Physical Exam Findings

- neuro screen, strength, ROM, single leg squatting, usual "functional tests" are all normal

- no significant pain on palpation of entire lower leg

- positive Slump test with a bias toward the superficial peroneal nerve.  This also occurs during a straight leg raise test with a superficial peroneal nerve bias.  The sensation felt is the same as that felt during running.  The video below is essentially the test movement (except change the ankle dorsiflexion for plantar flexion/inversion)

http://youtu.be/Xy1Lv3FK2Dk

Running Analysis

In the video below I noticed two things that may be significant.  This runner is predominantly a forefoot striker even at slow speeds.  Quite rare.  She essentially reaches out for the ground with her forefoot.  If you notice her knee it is actually quite extended just before foot strike.  This is not normal. See a kinematic review of running here. There is usually quite a bit of knee bend before landing and of course on impact.  Simply, this runner overstrides with a forefoot strike. She does this both in shoes and in socks.  This position is similar to the Straight Leg Raise test with a peroneal nerve bias and it may be contributing to the "funny" feeling in the leg.  A review of running biomechanics with video can be seen here.

http://youtu.be/h7W7cWYhCDw

Differentials

I can't rule out exertional compartment syndrome but I also can't confirm that with ease as the test would take over 3 months to get here in Toronto.  And Andy Franklyn-Miller (UK sports doc with a great deal of experience studying this type of thing -  website here) would suggest that this test is even questionable for this condition and we might even want to question the condition itself.  So I keep the exertional compartment idea in my head and look at other possibilities.

Why I question the compartment syndrome is the positive response I get when I stress the superficial  peroneal nerve with neurodynamic testing.  I don't believe that this is a classic response for exertional compartment syndrome suggesting to me that we have an altered neurodynamic on our hands.

Treatment

- explain pain, always explain pain

- at home - every hour, 5-6 nerve sliders for the peroneal nerve (video below but don't dorsiflex the foot)

http://youtu.be/y-cXei4e_wM

- running changes: this is tough but our runner is working on a midfoot strike and is trying to cue the idea of landing behind her (this is impossible but it can get the idea across).

- I also treat the "container" of the nerve.  I do gentle soft tissue work (I used to be an  A.R.T guy but I am much gentler now and don't believe the theory they propose) along the entire sciatic nerve. I think that I am really the nervous system and ultimately influence the muscle and the peripheral nerves with my manual therapy.  You can explain this treatment anyway you like. I choose a neural based explanation rather than thinking that I am digging out adhesions.

- I believe runners should be strong.  And not just runner strong - athlete strong. This runner has had previous high hamstring tendinopathy/tearing (or possibly sciatic nerve or all the little nerves back there irritation) so she is on a heavy resistance training program for everything.  I don't emphasize anything - I just train for balance, capacity and variety.  She gets exercises like one leg deadlifts, deadlifts, squats with bands, hip thrusts, hip airplanes, bridges, clamshells, one leg squats, one leg lateral wall squats, nordic hamstrings, push ups, suitcase carries etc.  Click here for a "hamstring" injury for runners sample program for videos

Is she better?

Sorry, don't know yet.  Just started.  Any ideas please let me know.  I can say that after I gently treat the region around the sciatic, tibial, peroneal nerve we are able to decrease the sensitivity associated with the SLR testing. This is a good sign. I am cautiously optimistic.