I generally don’t consider myself to be much of a ‘quote guy’.  I enjoy reading great quotes and often find meaning in them in the moment, but generally stop there with very rare exceptions.

 

There is one quote that violates this.  I often use it as a lens when I learn something new that challenges one of my beliefs.

 

“Have strong opinions loosely held.”

 

It is one of those quotes that has been attributed to historical figures from ancient stoics all the way to Jeff Bezos whose company Amazon used a derivative of this quote as one of their guiding principles; ‘Have backbone; disagree and commit.’   This was to recognize the idea that you should be able to present things you believe to be correct, but also be willing to accept that you may be wrong.

 

I love this idea and think I’ve gotten better through the years at recognizing my own dogma on certain topics.  The best illustration of this at our practice is our hope that the exercises we assign and treatments we provide are far different today than they were 10 or even 5 years ago based on our integrating new information that challenges our biases.

 

If you follow us at all, you know how important Dave and I think foot exercises are.  One of our most viewed youtube videos is on intrinsic foot exercises, where I show a bunch of tough to perform isolated exercises for the little muscles in your feet.  Over 46,000 different people have watched this one.  But, that video is 11 years old (as evidenced by my thick head of dark brown hair).

 

We are passionate about foot strength and have been passionate about intrinsic foot exercises as we viewed these as the best ones out there to isolate the little muscles in your feet.

 

BUT, an article came out in the past year that challenged my bias of what works best to strengthen those little muscles that are so important to foot health.

 

In the 11 years since we published that first intrinsic foot strengthening video, we have actually put out 6 more videos on intrinsic foot strength exercises, many specifically targeting plantar fascia pain.  This shows how strongly convicted we are to intrinsic foot strength.

 

I can safely say my opinion has now changed and the exercises I will prescribe to target these little muscles will follow suit.

 

…..Strong opinions, loosely held…..

 

So what exactly are the best exercises for your feet?  Well first let’s give some background on this paper.

 

Generally we know that negative changes in the plantar intrinsic foot muscles (the small muscles on the bottom side of your foot) are associated with aging but also with conditions like plantar fascia pain, chronic achilles tendon issues, ankle instability, diabetic neuropathy, and even having big bunions.

 

This is important because contracting these muscles helps control the big arch on the inside of your foot when you are weight bearing or when your balance is challenged.

 

This premise is old.

 

In the past, the standard run of the mill exercises you would be prescribed to try and get these small muscles strong would include things like trying to curl a towel up with your toes, or pick up marbles.  In fact, I’m sure many of you reading this have been given these exact exercises at one time or another.

 

We abandoned these exercises years ago as clinically we found them to be ineffective.  In fact, that was the reason we even made that video 11 years ago….to present alternatives to these canned run of the mill approaches.

 

Recently it’s been shown that using these ‘standard’ exercises like the towel grab as a means to strengthen the intrinsic foot muscles is actually counterproductive as they tend to rely on the extrinsic, larger muscles to accomplish these tasks and these larger muscles overtake the small muscles which then just compounds the weakness.  Brutal.

 

Next came the renaissance to ‘newer’ exercises like the ‘short foot’ exercise or toe spreading (like the ones in the video).  The issue with these is that while they do show increased toe flexor strength in a research setting, they have not shown structural changes to the muscles themselves.  They also have been shown to have inconsistent results from a biomechanical perspective when they test for things like balance.

 

One other note is that they are EXTREMELY difficult to perform.  In fact, research shows compliance with these little foot exercises is horrible when people have them assigned as folks just get frustrated and quit trying to do them.  The only reason I’m pretty good at them is from countless hours of martial arts as kid, all barefoot, which in my mind ensured the development of fairly strong foot muscles and good neuromuscular control.

 

So if the exercises we prescribe aren’t building muscles (as judged by structural changes), and aren’t really increasing a persons function via improvements in balance for example, combined with their difficulty to perform…..maybe we need new ones!

 

This paper compared these classic intrinsic foot exercises, with four ‘functional exercises’ to see which ones actually activated the intrinsic foot muscles better.

 

They used a simple but beautiful definition of a functional exercise; that they are habitual movements that challenge the intrinsics in the same way they act in usual daily activities or sports activities.

 

Think about that for a minute.  When I used to assign little toe abductions, or the ‘piano key’ exercise, people may have gotten stronger while performing those specifically, but they weren’t getting stronger in their feet when they lost balance, or had to go up on their toes.  It makes me questions if there is actually any point to many of those prior exercises……strong opinions loosely held.

 

For this paper the functional exercises all had to be weight bearing for many reasons.  As an example, obviously when we are doing anything (walking, running, even standing) these muscles are working both concentrically (shortening) and eccentrically (providing control while lengthening).  Exercises like the towel curl or isolated movements really only work these muscles as they are shortening.  Also, these isolated exercises do not challenge your balance at all.  BUT, exercises while standing certainly do.

 

Finally, on a more minutia level, the biomechanics are important when people are flat footed versus up on their toes.  When you are on your toes, the centre of pressure moves down along the toes past the ‘big knuckle’ (your metatarsal phalangeal joint).  It has been shown that when pressure is there instead of over your whole foot, you get increased activation of the intrinsics because these muscles largely span the MTP joints and are forced to create maximal toe flexion to resist the force generated by the ground when you are on your toes.  For the engineers reading this, essentially you have a longer moment arm so the muscles are forced to work harder.

 

The study itself used 29 participants with average age 23 from a University in the Netherlands.  Importantly none of them had any foot issues.

 

They attached surface EMG electrodes via ultrasound to ensure that they were placed on the muscles they were looking to assess.  They chose 4 muscles.  Three of these were superficial intrinsic muscles that help for the arch, and one was a big toe flexor that they used to represent the extrinsic toe flexors.

 

 

 

 

Once in place they had each participant perform 5 static isolated ‘traditional’ foot exercises and their 4 functional ones (2 were static and 2 were dynamic).  They got to practice each exercise once and then perform 3 trials.

 

Here are the exercises they had to perform (you may recognize many of them):

 

Here is the most important chart from their findings:

 

This chart essentially shows how the each of the 4 ‘functional exercises’ faired against the isolated exercises for the 3 intrinsic foot muscles they assessed.  The straight line across the middle can be considered the mean score for the intrinsic foot exercises.  The bars in the chart show how these muscles did for each of the 4 functional exercises.  If the bar is above the centre line, it means that the muscle being assessed scored higher activation in the functional exercise, than in the isolated ones.  As you can see it was essentially a ‘clean sweep’ for the functional exercises.

 

They concluded that their functional exercises provoked comparable or even more activation of intrinsic muscles than isolated foot exercises.  It also took far fewer repetitions to get to the same activation level which is important.  For instance, just 3 reps of heel raises got the same activation level as a set of 10 repetitions of an isolated exercise.

 

Other important findings?

 

• Isometric exercises like the held heel raise actually had the highest activation levels.
• Concentric exercises had the highest activation of the EXTRINSIC foot muscles which is what we are trying not to do.
• Doing a forward lean during the exercises (which is a common cue provided by therapists) actually did not change the intrinsic muscle activation at all.
• The ‘toe stance’ (calf raise) position performed best likely because it requires to calf muscles provide substantial force that has to get transmitted into the ground which then gets transmitted back up and has to be counteracted by the intrinsic muscles.
• The ‘toe stance’ also makes you have an unstable posture which increases the postural challenge again contributing to higher intrinsic muscle activation.
• Overall they claim to best challenge your feet, think of stiffening the feet via doing a calf raise and add balance challenges.

 

So what have we learned?

 

First off, it should be no surprise that the functional exercises the researchers included had higher activation patterns.  They were weight bearing while the isolated exercises were not.  Also, all of these exercises had participants go up on their toes which activates a mechanism called the Windlass Effect that essentially locks your arch and loads tension up like a spring.

 

While this may not be surprising, it does match with the principal of specificity of training.  Want to get stronger feet to perform tasks like ambulation and balance?  You’d better train standing on your feet!

 

Adherence was also far better with these exercises……because people are actually successful performing them!  Ask someone to move their little toe out to the side and they give up quickly.  Ask them to walk around on their toes and it’s not a problem.  In fact, a prior study showed even for healthy younger individuals, when they were asked to try and learn isolated intrinsic muscle exercises, they generally gave up after 2 weeks of daily training because they just couldn’t perform them.

 

The one downside to this is the potential discomfort if a person has a pre-existing condition like achilles tendon problems, or plantar fascia pain where going up on their toes or hopping may be a problem.  Same goes for deconditioned individuals who just can’t handle being up on their toes like this for any period of time.

 

Overall I likely won’t abandon the isolated exercises altogether.  That said, I am a HUGE fan of simplicity.  The knowledge that I can get a superior activation of intrinsic muscles using easier exercises that people will actually comply with is a big finding clinically and will change my exercise prescription moving forward.

 

Strong opinion……loosely held.