Your cranky nerves: A primer for patients to understand pain

Audience: Patients with any type of pain or injuryPurpose: to learn a little about pain and convince you that pain is not in your head even though your brain plays a big role

Why? Understanding pain helps decrease pain and helps us make better choices in the treatment of injury

Some brief pain information tidbits

  • you don't need a leg to feel pain in that leg (e.g. phantom limb pain)
  • you always need a Brain to feel pain
  • pain can become a habit - and like all habits lots of factors help keep it going
  • Changes in how we feel pain can also come from changes in the brain and the nervous system
  • tissue damage or degeneration does not have to lead to pain - but it certainly can

Damage does not always equal pain


The idea that lots of pain equals lots of damage is a very difficult concept to shake.  It is entrenched in how we think about pain, arthritis, surgery and injuries.  When we have pain we want to know what is causing it. We assume there must be something damaged and that causes our pain.  The problem with this is that the majority of us are walking around with some degenerative joint disease, disc protrusions, tears in our shoulder rotator cuff and all kinds of things that look like damage YET we have no pain.  Conversely, you can have a lot of pain and all the imaging shows that there is no damage.  This can be extremely frustrating for someone in pain. Take a look at this rather dry post that details a number of research studies showing the poor relationship between joint damage and pain.

However, sometimes damage certainly does lead to pain.  If you break your arm it will hurt.  But in a week, that arm will still be broken but you can be out of pain.  I also know, that many people with hip degeneration are in a lot of pain, they then get a hip replacement and they are out of pain.  This is wonderful.

So why does some damage end up leading to pain and other damage doesn't?

Several factors can contribute to our experiencing pain.  The leading theory on pain is the Neuromatrix Theory.  In a crude nutshell, it suggests that the brain ultimately decides how much pain you will feel.  The brain takes in all kinds of information and then makes a decision.  With a recent injury we think that you feel pain, swelling, weakness, tightness, guarding all because the brain is trying to protect you.  The area of the injury will get more sensitive and your brain can get better at producing pain.  The brain thinks that pain is a good thing.  Unfortunately, pain can persist for a long time after the pain is useful.  For whatever reason the brain, your nerves, your muscles, your immune system, your endocrine system all stay sensitized.  Its now easier for you to feel pain.

But none of this is all in your head.  In fact, this is how athletic excellence works

The brain learns and you become a better athlete/guitar player/knitter


In some ways we can think of pain as habit.  Our nerves and brain get better at making pain.  Now, I know this sounds like I am saying this is psychological because I'm talking about the brain.  But would you ever say its psychological when you get stronger after working out for 6 weeks? Of course not, but after exercise training much of the reason we get stronger or perform better is because the brain and nervous system become better at the task.  This is similar to what happens with pain.  We get sensitized and better at producing pain.

Pain is neither a barometer or a GPS

The pain we feel gets out of whack with any damage we have.  The pain becomes the bigger problem than any wear and tear.  Pain is now a poor guage of how much injury there is.  Pain is also horrible for telling us where the problem is.  Where do people feel pain when they have a heart attack?  Their arm, neck, chest and back.  There is nothing wrong with their arm.  This is how we need to think about pain.  It is just an alarm that goes off.

The overly sensitive alarm

NO! Don't make me do crunches!
NO! Don't make me do crunches!

If a fire alarm goes off in a building we have no idea if the alarm is due to a large fire, lighter held underneath a sensor, a little bit of smoke or even some problems with the wiring.  We can even put of the fire and the fire alarm will still go off.  This is how we can think about the pain alarm that goes off in our body.  It can stay on long after any damage has healed. You can even think of pain as a cranky toddler.  The pain or response of the toddler is often out of proportion to their injury.  At an unconscious level this is what can happen with our body.  A disconnect between damage and pain and we are left with screaming joints or muscles.

Again, the pain is not in your head

You might ask why I keep talking about cranky nerves and a cranky brain when you know that there are problems with your muscles and your joints.  I would probably agree with you.  When we have pain for awhile we move differently.  We can get weaker, we can get stiffer, muscles can compensate, you might slouch or limp or move poorly.  All of these things can either be caused by your pain or can be contributing to it.  Addressing them can be helpful but surprisingly it is not often necessary.  Often, we can change your pain immediately and you will have immediate change in strength or range of motion.

Treatment is about decreasing the sensitivity of the system

You have threshold to where you feel pain.  Treatment is about increasing this threshold.  This can be done a number of ways.  Good treatment should try to address as many different factors that influence pain.

The significance of everything above means that you can have damage. You can have joint degeneration and certainly can have the normal wear and tear associated with arthritis.  Whats great is you can change the amount of pain that you feel without ever changing the amount of arthritis, wear and tear or even damage in different body parts.

Treatment helps turn down the sensitivity of our nervous system.

See here for a description of my treatment approach.  But what we need to remember is that since pain is influenced by many factors many things can influence the pain we feel.

Related Pain Links

1. Pain videos


Strength first, core last: Modifying core training for runners

front bridge from knees
front bridge from knees

Don't get me wrong.  I love respect the core. But you can't open a running book, magazine or blog without hearing how important it is for runner's to train the core.  I agree with this to some extent but for 10 years I have advocated for three points to keep in mind when it comes to runners and core training:

1.  Core training should come second to a general strength and power training program.

2.  You can adequately train your core without doing a bunch of traditional core only exercises.  This is a whole blog post that you can see here.

3. If you are going to focus on the core consider training for strength and do less endurance core exercises (if you do 5 minutes or more of continuous planking then I'm talking to you).

Point 1. General strength and power first

Despite the core's dominance in the sports medicine field and popular culture there is very little research that basic core work actually improves running performance, improves posture or makes you more efficient.

A couple of studies show an improvement in running performance (here) with one showing no change.    A slightly related review on core training found only marginal benefits of core stability training to athletic performance.  Lest anyone think I am going out on some Maverick limb here and that I'm a contrarian-prick my thoughts have been mirrored in other published reports questioning the benefits for simple core exercises for athletic performance.

I recognize that a lack of evidence does not mean we should stop training our core for runner's but when we have a huge amount of evidence for another intervention and a limited number of training hours then we should allocate our training time accordingly.

Guess what research dwarfs the core research?

deadlift start1
deadlift start1

Lower body strength and power programs.  There is a huge body of research showing that heavy strength training or power training (e.g. plyometrics) improve running economy and race performance.

Here area some blog posts and a few research papers:

1. From Tom Goom the running physio: resistance training for runners.

2. From the sports physio Adam Meakins: should endurance athletes do weights?

2. Maximal strength and explosive strength both improve performance

3. Training heavy improves performance

4. Strength training superior to endurance strength training for performance

5. Strength training again superior to endurance strength training for performance

6. Ten year old research (nothing is new) showing improvements in running economy after heavy resistance training

7. A systematic review suggesting improvement in running economy

The theme in the above studies (and they are just a small sample) is that maximal strength training is either superior to endurance-strength training (i.e doing more reps of a lighter weight) or just as good at improving running economy.  Meaning endurance athletes should stregth train and lift heavy.  Explosive training (often plyometrics) are also beneficial in improving running economy. There is no research saying we should not be strength training.  So get off your planks and grab a bar.

Why is the core not of extreme importance?

The hips and the calves produce power and should be treated as supreme

The trunk muscles (erector spinae, obliques, rectus abdominis, transverse abdominis)  aren't the primary drivers of locomotion in endurance athletes. They are important they just need to be put in their place.  This is not an all or none thing but they take a back seat to the legs and hips during running and our training should reflect this (see Tim Dorn's research here and here, an old post of mine here and Sam Hamner's research here and here).

2. You can train the core without actually targeting the core

I want to reiterate - the core is still important.  No part of the body should be neglected. But perhaps there is a more efficient way to train the core. This was my big research thesis 7 years ago that was quashed with all my other mediocre research dreams when I was pushed out the door of chiropractic college I worked at :). In our pilot work we were seeing trunk muscle EMG activity during squats, deadlifts, cleans, jumping, pull ups, pushups etc that was comparable to the activity seen during traditional core exercises. It wasn't as high as we thought but it was still comparable to standard core exercises (The reason it was not as high as we predicted was later explained in an excellent paper by Stu McGill here)

You can read an entire post on this topic here.  But the take home point is that exercises like the deadlift, squats, push ups, kettlebell swings, kettlebell snatches, Olympic lifts, probably pull ups, probably jumps and sprinting train the core to comparable levels as basic core exercises do.  Yes, you can certainly focus on weaker areas with basic exercises and you might want to do this if you are working with someone doing corrective exercise work but for the average runner you get a lot of bang for your buck when doing compound strength exercises.

#3. Train the core to get strong - stop doing "tempo" only core workouts.

See Bret Contreras to get strong
See Bret Contreras to get strong

When you are running your core muscles work less than 30% of their maximum.  So in effect, running is a core exercise to train the endurance ability of your trunk. If you run 6 days a week for an hour that is 6 hours of core training.  Simple adding 10-15 minutes 3-4 times a week of basic core exercises does not really add much to the endurance ability of your abs/trunk.  You need to do something different and stress your trunk to a greater degree.

If you are doing more than 3 minutes of continuous planking what energy system are you training?  If you are training 10-15 minutes of gut-busting plank work 4-5 times a week what do you think you are doing?  Would you ever just do 200 squats in a row and assume this helps your running?  No. Yet this is what these drawn out core endurance exercises are akin to.  Would we ever train other body parts like this?  Would you do 5 intense tempo sessions a week and nothing else?  Why train your core like this?

Gut Busting core plank sessions are really "tempo" runs for your core

side profile lead pack3
side profile lead pack3

I think there is still some benefit in those brutal core workouts that you do where you work hard for 20-30 minutes. To determine its value you need to compare it to the quality workouts that make up the running you do in a week. What is that gut-busting workout akin to?  You work intensely for 20-30 minutes - does it sound like a tempo run? Would you do 4-6 tempo runs a week? No way. Thus, we should train the core the same way.

Your running provides endurance training stimulus for your core, your gut busting plank/trunk work is your tempo/quality work (1-2 times a week). If we stay consistent with our exercise training principles we should only do gut-busting core work at that anaerobic threshold level one to two times per week.  This leaves us with one more workout.

To have a fully comprehensive and balanced workout regime you now you need to add some power and strength to your core work.  We do the same thing with your lower body so lets do it with your core.

An alternative to your "tempo" core workouts

If you have trained your core for a long time its time to mix it up and get strong.  This might be the component that you are missing because you are doing too many "tempo" core workouts.  Training for strength or power may be the attribute your core needs to become well rounded and make you a better runner.  The mechanism for a core helping a runner can't just be about endurance.  Because if it were than just running would be sufficient.  The mechanisms for improving running by training the core may be explained by other neuromuscular characteristics that develop from strength training.  If so, we need exploit these.

Some suggested exercises to increase the strength challenge of your core.

1. Staggered Pushups

2. Ab wheel rollouts

3. Bridge Walkouts

4. Dead lifts

5. Side Bridges with leg lifts

6. High Knee Drives

7. Jumping tuck jumps

8. Medicine ball slams and throws


This is advanced.  You need to progress to this work.  That's where basic core exercises are good.  You progress as those basics become to easy.  Don't just do more of them.  If you squat 135 lbs for 8 repetitions when you start strength training nobody expects you to still do 135lbs 2 years later but now for 30 reps.  That is akin to the 5 minute plank.

A great article which shows how to do a number of excellent core exercises was recently written by Ben Bruno.  You can see the article here at T-Nation.  His writing of this sure saved me a lot of work.

Take home points

1. You should strength train and put more emphasis on general strength training than just your core

2. Many basic strength training exercises also train the core

3. Decrease the number of gut busting/tempo core workouts to 1-2 per week just like you do with quality runs

4. Basic running provides the stimulus for endurance adaptations in your core just like all your other systems

5. To train at true comprehensive capacity and be well rounded your core workout should also address strength and power not just endurance and speed-endurance.

Further Reading

1. Here is a nice complimentary blog post by Physio Tom Goom on training your core for running

Ditching the Plank? Strength training is core training.


Background The piece was part of a companion piece on resistance and "core" training for runners.  The thrust of that piece was that general resistance training should come first before gut-blasting 5 session/week plank marathon sessions should occur.

Purpose: core exercises are rampant and extremely hyped. They are much too popular and I think many athletes not working with strength coaches focus on the core and perhaps neglect other body parts.  A not at all new thesis is that many simple core exercises can be replaced by compound exercises that have other goals (e.g. train the legs) but still require great core activation.

deadlift down
deadlift down

When I was actively researching exercise biomechanics a goal was to try to document the EMG dosage of the entire trunk and hips during ever single exercise.  My thesis was that basic core exercises (curl ups, bird dogs, superman, bridges) were not necessary for many athletes and the general population.  I still advocated them to patient (and still do) but really thought you could have a comprehensive conditioning program without doing them -we could get an appropriate core workout by training squats, deadlifts, olympic lifts, sprinting, knee drives, plyometrics etc.  In our pilot work we were seeing trunk muscle EMG activity during squats, deadlifts, cleans, jumping, pull ups, pushups etc that was comparable to the activity seen during traditional core exercises. It wasn't as high as we thought but it was still comparable to standard core exercises (The reason it was not as high as we predicted was later explained in an excellent paper by Stu McGill here).

When I was a biomechanics researcher most of my work focused on cataloging the "dosage" of muscle activity during exercise. I wanted to create a massive document that quantified the muscle activation dosage for the trunk and hips during every exercise. But then I was slowly pushed out the door.  And naturally this type of research was not considered valuable at the chiropractic college where I worked.  Because, you know back cracking is so much more important for the body then exercise.  (where is the sarcasm font?).

Below, I am trying to catalog trunk muscle activity during strength training exercises that are not traditional simple core exercises.  It is a bit crude and not complete but if you know of other research please send it along.

You can train the core without actually targeting the core

I want to reiterate - the core is still important.  No part of the body should be neglected. But perhaps there is a more efficient way to train the core.

Below I will highlight the muscle activation of the trunk during simple core exercises and then compare this with the trunk muscle activity during compound lower body or full body exercises. What you will see is that the muscle activity in the core is comparable or exceeds that of traditional core exercises AND you are getting the true beneficial effect of working the legs and the hips.  All values are expressed as percentage of that muscle's maximum activity.

Prone Bridge (Pr Br), Side Bridges and Supine Bridges (Su Br) (from a crummy paper of mine here)

Table 1

(Pr Br = Prone Bridge, Su Br = Supine Bridge, IO = Internal Oblique, RA = Rectus Abdominis, EO = External Oblique - source: my old research here)

Curl ups and Leg Raises (My only good publication  Here)

Core muscle activity during Compound movements that don't specifically try to target the core


From our pilot work and some research findings a few years ago the amount of EMG activity in the anterior/lateral core was a bit of a disappointment. it was a lot less than we thought. I had hypothesized that the "ab" muscles actually worked a great deal during a squat.  I was wrong.  In the following table from Bressel (2009)we can see that ab activity during a loaded barbell squat at 75% 1 repetition max was pretty low.  The only muscle to see any significant activity (around 40% of max) was the internal obliques and only when the subjects actively braced their spine.s

An aside: A neat implication for this relates to the FMS test of the overhead squat.  I hear the great trainers at my work suggest that many people can't do a deep overhead squat because of the strength or stability of their "abs".  This never quite made sense to me.  Its an  unloaded movement and you don't need a lot of activity in this area.  Why would the front of the trunk need to be active.  There is no external torque that wants to extend the back and stability we should know requires minimal co-activation (less than 15% activation).  I can see why a weakness in erector spinae may be an issue but no anterior-lateral muscles could every possibly be a culprit.  Unless its a motor control idea but that needs to be fleshed out more.

Ab activity
Ab activity
Peak EMG activity from Bressel 2009
Peak EMG activity from Bressel 2009

In other work by the great David Behm's group (Hamlyn 2007) they concluded that the anterior and lateral abs were active to a comparable amount during an 80% squat, 80% deadlift, body weight squat, superman and sidebridge exercise.  This seems a bit odd since the side bridge can see oblique activity greater than 40% max.  This suggests the squat and deadlift exercise had comparable activity.  This is certainly in conflict with the Bressel study.  Unfortunately, the authors did not provide the amount of muscle activity that occurred in the abs during any of the exercises.  They just told us that there was no difference.

The Erector Spinae work their tendons off though

Where we do see huge muscle activation levels in the core during squats and the deadlift is in the erector spinae.  During heavy squats and heavy deadlifts (75-80% 1 repetition maximum loads) we see muscle activity greater than 100% of maximum.

Back muscle activity during exercise
Back muscle activity during exercise


From (Escamilla 2002) lifting a weight that corresponds to a 12 repetition maximum:  

Rectus Abdomonis: 60%

Internal Obliques: not studied

External Obliques: 56%

Erector Spinae @L3: 32%

Erector Spinae @ T12: 33%

Again, we see some conflicting activity here.  The previous studies muscle activation levels greater than 75% maximum yet Escamilla found much less.  Regardless, we certainly see significant activity in the core.

Push Up Variations:  (Freeman 2006)

Push ups are awesome.  You get huge anterior and lateral muscle activation especially when you increase speed and stagger your hand position.  What a great exercise.  Stop doing bridges just do push ups.

Kettlebell Swings (McGill 2012)

The following table highlights how well Kettlebell swings and variations can target the majority of the core.  However, we don't see a lot of activity in the rectus abdominis or external obliques.  These findings suggest that other exercises still need to be incorporated to train these muscles to full capacity.

mcgill kettlebell swing EMG
mcgill kettlebell swing EMG

Overview of core activity during compound exercises.

What we see here is muscle activity during compound movement exercises (Squats, Deadlifts, Push Ups, kettlebell swings) that is comparable to or exceeds that which occurs during many basic core exercises.   This means you can be evidence based and train the primary drivers of locomotion while still covering your bases and address all the muscles of the trunk.

In a nutshell:

- push up variations are excellent for the front of your core (rectus abdominis and obliques)

- loaded squats and deadlifts are great for the posterior and lateral core

- kettlebell swing variations train everything with the exception of the rectus abdominis

Going Forward and Limitations

We are missing (or I can't find it) is good data comparing plyometric or more ballistic exercises with traditional mat based core exercises.

The problem with different research groups is that they use different techniques and its difficult to compare across studies.  You can see that with the different results in almost the same exercises studied above

Anyone want to send me an 8 channel EMG unit and 16 fit volunteers for one week? Once you get research ethics approval you could literally hammer out the data collection on ten research papers in a week.

Some Caveats

- basic core exercises still have value.  Sometimes focusing on the core is necessary to get very high levels of activity in certain muscle groups.  An example would be the "stir the pot" exercise to target the anterior/lateral trunk.  You can't get these high levels of trunk activity if you do a cable  punch with heavy resistance (another surprise and arrow in one of my previous theories that we found in some pilot work).

- core specific exercise can still be valuable if you do some corrective exercise work.  I am not saying to stop doing that. If that is your philosophy and approach this article takes nothing away from that

- people with pain or dysfunction may also benefit from doing some core specific work.  These could be bird dogs, glut bridges or pelvic floor work.  There is still value in these exercises.  I'm not saying to abandon them

Static stretching: not evil, not a panacea just a

This brief post has two main points:

Static stretching is not going to kill your performance


Static stretching is not a cure-all

Further, nothing in this post is even remotely new.

Are you against static stretching or just the nonsense that people have said about it?

The unsupported benefits of stretching may have caused many of us to look for reasons to attack stretching.For the past fifty years a simplistic view that stretching was both a cure and prevention for all musculoskeletal ailments has dominated sports medicine.  Many professionals and the media would suggest that you needed to stretch to not just prevent injuries (pick up any Runner's World Magazine before 2009) but to ward off delayed muscle soreness, align your collagen fibres after an injury, break up scar tissue, permanently lengthen muscles to fix your posture and as an cure for any injury.  Ugh.  These ideas were extremely opinion driven with little evidence.

We've known for decades that its injury preventative influences were rather weak or questionable (See Shrier 1999) and its actual influence on muscle and the function of the body were overblown and again questionable (a brief review here).

But just because stretching is not helpful for a number of things does not mean it doesn't have utility.

The evidence against stretching has mounted in the past 15 years

A body of work emerged showing decreases in power, strength, balance and/or speed following PROLONGED (>60 second holds) static stretching. (a nice review by a great Canadian researcher, David Behm is here and a more recent one is here). This work gave us more cause to question prolonged static stretching's wonderfulness as a panacea and gave us some insight on how not to stretch . A horrible thing happened with this evidence against static stretching.  The "stretching sucks" swing of the pendulum went too far with many not reading and critically reviewing the literature and then applying this research inappropriately to clinical practice.

So now the "cutting edge" is anti-static stretching.

But this is not cutting edge - the research is old and it needs to be applied with a critical mind to our practical applications.  Throwing static stretching away is not research informed.  This is the same as telling people they have to stretch to  prevent injuries.  We are again confusing Shades of Gray for Black and White.  Those strongly against static stretching and suggesting it should not be part of a good warm up are just as ill informed as those that suggested stretching was the answer to everything musculoskeletal.

A good blog post on the case for stretching (or at least reasons to hold our judgement can be seen here by Ben Bruno).  What I had read from the literature and what Ben stressed was:

Most of the research showing performance deficits following static stretching tested prolonged stretching protocols (greater than 60 second holds).  Most people in a warm up don't do this.

And that is it.  Prolonged static stretching of greater than 60 seconds (not what is typically done in a warm up) slightly decreases the performance during some simple activities.  There is no research showing long term changes in performance, nothing showing an increase in injury risk, no reason to think that your joints become unstable or more susceptible to injury and no reason to think that stretching impairs our ability to adapt to a training stimulus.  Just maybe don't stretch for longer than 60 seconds before an event.  Not that anyone every did this any way.

We need some caution in dismissing stretching

Stretching  can still be a useful tool in appropriate situations.  I'm not going to tell that runner who has been injury free for 15  years and stretching before every run to stop stretching.

Further, we also should not generalize prolonged static-stretching's negative influence involving simple tasks across all aspects of human performance.

For example, a decrease of isometric ankle strength followings stretching does not mean a long distance runner will become more inefficient when running a 10k (and yes, this has been studied with decades of research, albeit conflicting, but much showing no change in running economy following stretching).

An example can be seen from my work as a mediocre researcher where we conducted a small, unpublished study in 2007 on trunk kinematics during the golf swing following a 60 second trunk rotation stretch. I was hoping to see losses of performances so I could get the thing easily published.  Ideally, a decrease in trunk rotational velocity.  Of the nine subjects, none decreased their velocity.  Interesting, there were also no changes in spine rotation, the x-factor or the x-factor stretch.


Final Round Up - I am not saying to got out and statically stretch every athlete as a warm up

What I am suggesting is that we need some caution in just catastrophizing over simple exercises.  Static stretching can still have its purpose.    Even when I was a big anti-stretchite in the early 2000s I would warm up and static stretch during golf.  It did not change my performance and I needed the range to swing fluidly.  The demands of my sport and the limitations in my function determined what I needed to do to prepare.  This is how we need to treat all of our best practice recommendations.  Perform a needs analysis of your goal task, compare it to your athletes ability and determine what matches and what needs work.

Maybe you have a sport that just needs a fantastic warm up as the demands of the sport don't see any athlete's joint ranges come close to their maximum (many long distance runners for example).  These athletes may not need to stretch.  But maybe you need to prepare an athlete for the extreme range of movement they need in the sport.  You can have science on your side and incorporate a little static stretching (e.g. 10-30 second holds) and not have to worry about their performance suffering.  You only have to worry about a former pro-stretcher now evangelical anti-stretcher tweeting that sky is falling because pro football players were stretching when the lights went out during the Superbowl. Ugh.

To conclude I think its best to listen to David Behm:

Generally, a warm-up to minimize impairments and enhance performance should be composed of a submaximal intensity aerobic activity followed by large amplitude dynamic stretching and then completed with sport-specific dynamic activities. Sports that necessitate a high degree of static flexibility should use short duration static stretches with lower intensity stretches in a trained population to minimize the possibilities of impairments.

Functional exercise is a poor term. How about some comprehensive Capacity?

originally posted at in 2012/13 and then updated in 2015. Here is an old post slightly reworked.  Please read Eric Meira's post on functional exercise that is just fantastic.

A few years ago 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 tellyou, I convinced no one :)

The consensus against me was that the clamshell sucked and that the band walk exercise was superior because it was more "functional" for runners.  I tried to argue indeed the bandwalk might be a better exercise but  not because the Bandwalk was more "functional".

The problem is the word "functional".

What the heck 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.

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.  Furthermore, 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 rarely 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 throw 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 contrary to 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 - thus no specific running exercises.

OK, so is the clamshell better?

No way! The clamshell sucks most of the time.  I used to hate clamshells because I thought I was better than that.  I thought runners should never do it.  I thought it was remedial and "non-functional".

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. I sure can't say if it is problem but if an athlete can't do something so simple, in a muscle group relevant to performance, then perhaps I should address it.

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 I 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 (plyometrics), variable range (not just mid range but end range and weird stuff) 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.

An aside: If you train "comprehensive capacity" and have a well rounded training program do you really need to do in depth assessments?  Don't your exercises become your assessments? Or your exercise regime is so well rounded you address everything an assessment might tell you.

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, mechanically efficient and may make them less injury prone.

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



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.

Neurodynamic Nerve Slider Pictures - helping people with pain

Below I have created neurodynamic nerve slider pictures.  I use them in handouts for patients and now you can too!  They are strongly inspired (ahem, completely based on) David Butler's work.

ulnar nerve contralateral neck flexion slider
ulnar nerve contralateral neck flexion slider
ulnar nerve ipsilateral neck flexion with tensioned distal
ulnar nerve ipsilateral neck flexion with tensioned distal
femoral nerve end
femoral nerve end
femoral nerve glide with hip flexion
femoral nerve glide with hip flexion
long sitting knee bent
long sitting knee bent
long sitting knee straight
long sitting knee straight
median nerve contralateral flexion
median nerve contralateral flexion
median nerve slider start
median nerve slider start
radial nerve contralateral neck flexion
radial nerve contralateral neck flexion
radial nerve wrist flexed and pronated
radial nerve wrist flexed and pronated
slump slider neck down start
slump slider neck down start
slump slider neck up knee straight
slump slider neck up knee straight
slump slider start
slump slider start
slump slider with peroneal nerve bias
slump slider with peroneal nerve bias

Dear Julie: In defense of the crunch

Dear Julie, You wrote an interesting letter on your beautiful website ( to the coach of your girl's gymnastic program.  You wished to

share with you and your staff how a decade or so of research is transforming our understanding of how we create a strong sturdy center that anchors all of our movements

As a father of two young girls (5 and 3) I really appreciated your views on healthy sports participation, concerns about body issues and the importance of fun in physical activity.  Like you I am also a physiotherapist with a special interest in spine function. I am also a chiropractor, was a spine biomechanics researcher, I completed a MSc in Spine Biomechanics with one of the authors of the references you cited (Stu McGill), I have published a few papers on trunk muscle function (here, here and here) during a variety tasks and was initially very interested in doing research on the lowly and often derided abdominal crunch (here and here).   I love talking about spine stability and how much of this actually old research (I don't think it's emerging, most has been around since the 90s) is applied to clinic or sport in ways that the research does not actually support.  I am also a former recreational gymastics coach and regularly "threw back tucks" after two beers at parties well into my twenties.

The big issue you had with your coach was his use of the crunch in his conditioning program. This was the area where our views seemed to differ. I think at best the jury is still out on much of what you have said and at worst the scientific data does not actually support your beliefs.

NO! Don't make me do crunches!
NO! Don't make me do crunches!

NO! Don't make me do crunches!

I personally don't think any exercise is bad.  It may be inappropriate at different times in a training cycle or there may be other exercises that are better for the specific goals of an athlete. But I rarely throw any movement under the bus.  The data just isn't there for that. In this letter I was hoping to give my rationale to defend the crunch and to discuss some of arguments you and many others (I think I'm in the minority) had against it. In the next few paragraphs I will cite the most common arguments against the crunch and give a rebuttal.

Argument #1:  "Overused abdominals result in bums tucking under and the lower spine flattening"

I noticed that there was actually no reference for this statement.  I would suggest that is because the research that has investigated the idea that strength training a muscle causes it to plastically deform and become shorter at its resting length and then pull bones into different position is actually lacking. I've written on this previously and for a review you can look here showing how strength exercises do not significantly change posture.  While this is a common idea it just doesn't happen.  Anecdotally, you will probably see the opposite postures in gymnasts. The tend to anteriorly pelvic tilt despite all those crunches.

gymnast apt
gymnast apt

A dominant motion in gymnastics is extension hence the concern by some for gymnasts to develop Spondys. Further, by what mechanism would even 15 minutes of crunches daily overcome all of the other neutral spine or extended postures that a gymnast undergoes?  While I recognize muscle "shortening" as a common belief, it is certainly not supported in the "10 years of emerging research".  Rather, it dates back to outmoded views of function perpetuated in the 1950s by Kendal and Kendal that somehow persist to this day.

Argument #2: Flexing the spine compromises spinal function

Gymnasts flex their spines.  The do this under load and they do it repeatedly.  Take a look at the gymnast doing the front tuck and the one doing the release on the parallel bars. Kind of looks like a crunch.

OMG, I'm flexing my spine.
OMG, I'm flexing my spine.
crunch with a vsit
crunch with a vsit

Most athletic sports don't have rigid spines all the time.  Gymnasts certainly train to have a "tight body" but they also move.  The spine generates and prevents movement.  In gymnastics we perform front tucks, back tucks, back handsprings, back fulls etc. There is an approximation between the ribcage and the pelvis in these movements, under high loading.  It happens.  Thus we should train it. I love planks (I've had to defend planking in the past) but they don't mimic all of the demands of gymnastics.  That is the purpose of conditioning - an overload stimulus to prepare for the demands of the sport.  And remember, a curl up is not just the rectus abominis.  Both obliques can be activated more than 50% MVC and the transverse abdominis also turns on substantially more than any indrawing exercise.

You mentioned that the ideal spine stabilty occurs with the co-ordinated action of all muscles.  This is true but in order to progressively overload a muscle group to ask it to adapt we have to train in a somewhat isolated manner.  To achieve strength adapations we probably need the MVC values to exceed 60-70%.  Curl up variations can do this. Imagine if we trained all of the of the muscles of the trunk together as a team exceeding 60-70% MVC.  The compressive penalty would be massive as would the increase in IAP.  The spine would be in neutral but you would still be loading it incredibly - far greater than what would occur in the simple crunch. I would even guess that our neuromuscular system would not even allow such high levels of loading to achieve a strength response (for example see here).

Bottom line: gymnasts flex their spines thus we should prepare them to flex their spines under load

Argument #3: There are better exercises than the crunch

Yup, that is a good argument.  You suggest planks (just as the coach did) and go on to suggest cartwheels and handstands as being even better than the plank.  I think arguing that there are better exercises for gymnastics based on specificity or effort level is a good argument but it does not mean crunches are evil.  Gymnasts could do V-snaps, leg lowers, rockers or other things that mimic their demands.  However, the lowly crunch is a good progression.  As for the cartwheels and handstands, aren't the girls already doing this during the session?  The point of a conditioning component is to overload and stress the system to create adaptations.  We want to choose exercises that are often a greater challenge than the goal task (cartwheels and handstands).

Argument #4: Crunches are dangerous because of spinal compression and disc strain

Again, a gymnast will flex their spine during the sport.  There is probably more compression and shear during their gymnastic activities than the crunch.  The crunch prepares the body to tolerate this load.  Crunches are rather innocous relative to other exercises and tasks.  What is  3-4000 newtons of compression and some shear?  Thats nothing.  If they do an L-sit on the parallel bars that demand will exceed the crunch. Or a kip-up on the uneven bars.

If we use compression and shear loading as the arbiter of safe activity we should get our kids out of gymnastics.  Most of those activities will exceed NIOSH's limits.   You quote Stu's book but we should go back to his original papers in the 1990's and we can see how low the compressive and shear penalties a crunch has in respect to all the other tasks we routinely ask athletes to perform.  I don't see spine flexion as all that evil.  Bret Contreras wrote a nice review questioning whether spine flexion is all that bad.  At the very least, it is a grey area.  Hence, I tend to have an issue with absolutist advice knocking one exercise.

Argument #5: Crunches create abnormal intra-abdominal pressure

Most spine exercises that will train capacity or stability of the trunk under high loads will create an increase in pressure.  This increased IAP creates stability.  Again, if we train with smart progressions and protocols the trunk and the whole musculoskeletal system will adapt as it should.  You wrote:

For the diaphragm this results in a change in breathing patterns, including breath holding, to meet stability challenges, and reduced respiratory capacity.These scenarios will create an issue for sustained respiratory support for endurance in athletics. The pelvic floor may not be able to match the excessive pressure from above, which can lead to incontinence

I'm not sure what the issue is here.  If you are concerned with breath holding, have the kids breathe during a crunch. Breath holding is normal and certainly even beneficial in my opinion if you want to increase stability especially during a landing or a back tuck. And while respiratory capacity might decrease while you are doing a crunch it does not carry over into prolonged dysfunction. How would it?  I don't even know what "sustained respiratory support for endurance in athletics" means or how it can possibly be compromised by a crunch.

As for the pelvic floor, maybe the crunch should be the least of our worries. I would hazard that the IAP will increase to a greater extent in all of the other more challenging activities that occur in the performance of gymastics. Is it the flexion coupled with a little increase of IAP that is so bad? No papers you cited and I doubt any research shows this. But again, I think it is a far reaching conclusion to suggest that crunches lead to urinary incontinence.  The studies you cited certainly don't support this.  The Sapsford study you cited tells me that the pelvic floor muscles have greater muscle activity during upright sitting. Super.  So they have less activity when your spine flexed.  Why is this a concern? The Biceps muscle functions better at midrange yet we still train the muscle through its full range.  Same with every other movement in the body.  Why is just the spine that we avoid ranges of movement that have less than optimal force production?

Random Argument #6: The crunch isn't functional.

I think this depends on your goal task and your beliefs behind exercise prescription.  I think in some sports we flex our spines and that flexion creates movement and is necessary.  Take a look at my golf mechanics e-book.  You will see in the kinematics graphs that trunk flexion is one of the first movements to start the swing.  Think of paddlers that flex their trunk under huge loads and force production.


We are not always in neutral during sport and activities of daily living.  Should we not then train out of neutral?  Maybe the crunch isn't the best way, maybe you can use cables, or throw medicine balls at the ground but you are still training flexion.

And now for some random thoughts...

The creation of Nocebo with all this catastrophizing

I get worried when we use a biomechanical rationale to warn against the normal movement of simply bending our spines under load.  If you tell the coach the danger of spine flexing and he passes this onto the kids what are you putting in their head?  Don't flex the spine?  Again, the do this all the time.  They learn to think their spine's are delicate rather than this robust, beautiful structure with an immense ability to adapt to the strains we place upon it.  Now when told how dangerous the crunch is, they become hypervigilant and their threat detectors are ready to go off.  Our biomechanical models of teaching people not to bend in the workplace has failed and we have more persistent pain and disability days than ever.  Lets not do this in our impressionable young athletes.


I'm on board if people hate the crunch and think they can create a program that avoids crunching.  We could maybe critique the coach for not having some variety or some exercises that better mimic the functional demands of the sport.  But, where I think we can go too far is by  saying is such absolutist terms that some exercise is completely off limits and that is supported by recent science.  Its not supported - the evidence is not there for that absolute statement.  Right now, its an opinion.  I think coaches can still have science and evidence on their side for justifying the use of crunches.  This, like most coaching, comes down to preferences and experience - there are many paths to achieving a performance goal.

I end this letter much as you ended yours.  Please don't view this as an attack on you.   And to quote "I would be more than happy to answer any question you or your staff (i.e. like minded colleagues) may have as you try to assimilate this information".  If there is some information out there that I have not heard of please send it my way.  I am open to changing my view.  I don't get a nickel every time a kid does a crunch so they could be gone tomorrow if there is some actual strong evidence against their use.



Related Links

1. Jeff Cubos wrote a piece on gymnastics and movement which I remember liking at the time and then completely forgot when I wrote this.  Its worth a read: