Achilles tendonitis: Lift the heel, right? It does not appear so.

There was a recent article in one of our favorite journals, Lower Extremity Review which reviewed and expanded upon another study from Medicine and Science in Sports and Exercise titled “Running shoes increase achilles tendon load in walking: an acoustic propagation study.” We discussed some perspectives of this topic in one of our recent podcasts.
The article discusses a new technique (1,2) for looking at tensile loads in the achilles and looks at 12 symptom free individuals on a treadmill barefoot and in a shoe with a 10 mm drop (heel is 10mm higher than the forefoot) and found:

“Footwear resulted in a significant increase in step length, stance duration, and peak vertical ground reaction force compared with barefoot walking. Peak acoustic velocity in the Achilles tendon (P1, P2) was significantly higher with running shoes.”(1)

According to LER: “The researchers also found changes in basic gait parameters associated with walking in running shoes versus barefoot, which the author Wearing said may help explain the increased tendon load with shoes. Shoes increased mean ankle plantar flexion by 4° during quiet stance as measured by electrogoniometry. When walking with shoes, participants adopted a lower step frequency but greater step length, period of double support, peak vertical ground reaction force, and loading rate than when walking barefoot. The researchers also noted that participants’ stance phase was relatively longer (4%) during shod walking than during barefoot walking.” (3)

Of course, our big question is why?

Why would an increase in step length result in increased tension?

Perhaps, as the force that the heel would hit the ground would be increased because of a longer acceleration time (F=ma), and it so happens this is what they found. The friction of the heel striking the ground would accelerate anterior translation of the talus, which plantar flexes, everts and abducts, accelerating pronation. The medial gastroc would be called into play to slow calcaneal eversion and this would indeed increase achilles tension.

Or perhaps it’s the fact that

the foot will strike in slight greater plantarflexion

(at least 4 degrees according to the study) and this results in an immediate greater load to the Achilles tendon.  Go ahead and try this while walking even if you’re barefoot. Walk across the floor and strike more on your forefoot. You will notice that you have an increased load in the tricep surae group.

Does this slight plantarflexion of the ankle contribute to greater eccentric load during stance phase?

This would certainly activate 1a afferent muscle spindles which would increase tensile stresses in the achilles tendon.

This seems to fly directly in the face of the findings of Sinclair (4) who investigated knee and ankle loading in barefoot and barefoot inspired footwear and found increased achilles loading in both compared to “conventional shoes”.

Of course this also begs the question of what type of shoes were they wearing? High top or low top shoes and were the shoes tied or not? High top shoes seem to reduce Achilles tension more so than low top shoes, especially if they are tied (5).

Whatever the reason, this questions the use of putting a lift or a higher heeled shoe underneath the foot of people that have Achilles tendinitis.  Once again what seemed to make biomechanical sense is trumped by science.

We think training people to have greater amounts of hip extension as well as ankle dorsiflexion,  as well as appropriate foot and lower extremity biomechanics with the requisite  skill, endurance and strength is a much better way to treat Achilles tendonitis regardless of whether they’re wearing footwear or not.

Dr. Ivo Waerlop, one of The Gait Guys

References:

1. Wearing SC, Reed LF, Hooper SL, et al. Running shoes increase Achilles tendon load in walking: An acoustic propagation study. Med Sci Sports Exerc 2014;46(8):1604-1609.  http://www.ncbi.nlm.nih.gov/pubmed/24500535
2. Reed LF, Urry SR, Wearing SC. Reliability of spatiotemporal and kinetic gait parameters determined by a new instrumented treadmill system. BMC Musculoskelet Disord 2013;14:249.
3. Black, Hank. Achilles oddity: Heeled shoes may boost load during gait. In the Moment:Rehabilitation   LER Sept 2014  http://lermagazine.com/news/in-the-moment-rehabilitation/achilles-oddity-heeled-shoes-may-boost-load-during-gait
4. Sinclair J. Effects of barefoot and barefoot inspired footwear on knee and ankle loading during running. Clin Biomech (Bristol, Avon). 2014 Apr;29(4):395-9. doi: 10.1016/j.clinbiomech.2014.02.004. Epub 2014 Feb 23.
5. Rowson S1, McNally C, Duma SM. Can footwear affect achilles tendon loading? Clin J Sport Med. 2010 Sep;20(5):344-9. doi: 10.1097/JSM.0b013e3181ed7e50.

Achilles tendonitis: Lift the heel, right? It does not appear so.

There was a recent article in one of our favorite journals, Lower Extremity Review which reviewed and expanded on another study from Medicine and Science in Sports and Exercise we spoke about several PODcasts ago titled “Running shoes increase achilles tendon load in walking: an acoustic propagation study.”

 

The article discusses a new technique (1,2) for looking at tensile loads in the achilles and looks at 12 symptom free individuals on a treadmill barefoot and in a shoe with a 10 mm drop and found:

“Footwear resulted in a significant increase in step length, stance duration, and peak vertical ground reaction force compared with barefoot walking. Peak acoustic velocity in the Achilles tendon (P1, P2) was significantly higher with running shoes.”(1)

 

According to LER: “The researchers also found changes in basic gait parameters associated with walking in running shoes versus barefoot, which Wearing said may help explain the increased tendon load with shoes. Shoes increased mean ankle plantar flexion by 4° during quiet stance as measured by electrogoniometry. When walking with shoes, participants adopted a lower step frequency but greater step length, period of double support, peak vertical ground reaction force, and loading rate than when walking barefoot. The researchers also noted that participants’ stance phase was relatively longer (4%) during shod walking than during barefoot walking.” (3)

 

Of course, our big question is why?

 

Would an increase in step length result in increased tension? Perhaps, as the force that the heel would hit the ground would be increased because of a longer acceleration time (F=ma) and that is also what they found. The friction of the heel striking the ground would accelerate anterior translation of the talus, which plantar flexes, everts and abducts, accelerating pronation. The medial gastroc would be called into play to slow calcaneal eversion and this would indeed increase achilles tension.

 

Or perhaps it’s the fact that the foot will strike in slight greater plantarflexion (at least 4 degrees according to the study) and this results in an immediate greater load to the Achilles tendon.  Go ahead and try this while walking even if you’re barefoot. Walk across the floor and strike more on your forefoot. You will notice that you have an increased load in the tricep surae group.

 

Does this slight plantarflexion of the ankle contribute to greater eccentric load during stance phase?  This would certainly activate Ia afferent muscle spindles which would increase tensile stresses in the Achilles tendon.

 

This seems to fly directly in the face of the findings of Sinclair (4) who investigated knee and ankle loading in barefoot and barefoot inspired footwear and found increased Achilles loading in both compared to “conventional shoes”.

 

Of course this also begs the question of  what type of shoes were they in? High top shoes or low top shoes and were the shoes tied or not? High top shoes seem to reduce Achilles tension more so than low top shoes, especially if they are tied (5).

 

 Whatever the reason, this questions the use of putting a lift or a higher heel shoe underneath the foot of people that have Achilles tendinitis.  Once again what seemed to make biomechanical sense is trumped by science.

 

 We think training people to have greater amounts of hip extension as well as ankle dorsiflexion,  as well as appropriate foot and lower extremity biomechanics with the requisite  skill, endurance and strength is a much better way to treat Achilles tendonitis regardless of whether they’re wearing footwear or not.

 

The Gait Guys

 

References:

1. Wearing SC, Reed LF, Hooper SL, et al. Running shoes increase Achilles tendon load in walking: An acoustic propagation study. Med Sci Sports Exerc 2014;46(8):1604-1609.  http://www.ncbi.nlm.nih.gov/pubmed/24500535

2. Reed LF, Urry SR, Wearing SC. Reliability of spatiotemporal and kinetic gait parameters determined by a new instrumented treadmill system. BMC Musculoskelet Disord 2013;14:249.

3. Black, Hank. Achilles oddity: Heeled shoes may boost load during gait. In the Moment:Rehabilitation   LER Sept 2014  http://lermagazine.com/news/in-the-moment-rehabilitation/achilles-oddity-heeled-shoes-may-boost-load-during-gait

4. Sinclair J. Effects of barefoot and barefoot inspired footwear on knee and ankle loading during running. Clin Biomech (Bristol, Avon). 2014 Apr;29(4):395-9. doi: 10.1016/j.clinbiomech.2014.02.004. Epub 2014 Feb 23.

5. Rowson S1, McNally C, Duma SM. Can footwear affect achilles tendon loading? Clin J Sport Med. 2010 Sep;20(5):344-9. doi: 10.1097/JSM.0b013e3181ed7e50.

Midfoot strike in a non-zero drop shoe. Have you thought about this ?

Here is something to think about. As one midfoot strikes the foot during walking or running the individuals body mass is typically directly over the foot.  When this occurs in a zero drop shoe (ie. flat, your rear and forefoot are on the same plane) the tibia-ankle is at the very least, at 90 degrees. Meaning, the tibia is at the very least at 90 degrees and is at the very least perpendicular to the ground and plane that the foot is on.  And with just a little bit of forward body mass movement over the foot the critical and necessary range of 110-115 plus degrees of ankle dorsiflexion (depending on your reference source) is achieved. This means that one does not have to prostitute the foot into greater than normal pronation to drop the arch further to gain the extra amount of ankle rocker (dorsiflexion) that is necessary to pass over the foot.

However, think about this.  What if that same foot is in a stacked heel shoe.  There are plenty of shoes still out there that have a ramp delta that is above zero drop. So, what we have is a shoe that has the heel higher than the forefoot, a sloped shoe.  IF this same foot midfoot strikes what happens now ?

Well, midfoot strike now occurs in a relatively greater plantarflexed posture (ie. heel is raised higher than the forefoot because of the shoe). This means we are not anywhere near the 115 degrees necessary for normal gait, timely heel departure, timely forefoot load, timely hip extension, timely gluteal activation etc. These timely gait events are paramount to normal gait and when they are altered injury and altered tissue loads can occur.  Altered motor recruitment patterns are likely to ensue.  In the scenario proposed, as the body mass moves over the slightly plantarflexed foot we might now only get to 90 degrees of ankle rocker before the body mass is far enough forward to create the passive heel rise during late-midstance phase of gait. And when the body can only get 90 degrees of ankle dorsiflexion/rocker during midstance the extra amount of dorsiflexion range may need to come from some other joint.  It may come from more than normal midfoot pronation, knee hyperextension, knee valgus etc. This is potentially a long list of compensations.

Our point is simple here and at this time it is just a tip of the iceberg article for us.  But we thought we would put this idea out there to share some of the things we think about on a daily basis, and some of the things that get played out in our clinics each and every day. 

Changing your running form involves so much more than just changing your form. If you change to a midfoot or forefoot strike what kinds of biomechanics are you employing ? Do you have the neuromechanics to accompany these running form changes ? Do you have the necessary ranges of motion ? Do you have strength in potential compensation patterns to fend off both subtle and dramatic running form changes ?  If not, you might find out that your initial response is ” I just cannot do a midfoot or forefoot strike running form. I get foot pain, or knee pain, or hip pain.”

Conversely, think about this regarding our postulation above.  If you have been employing a midfoot strike or forefoot strike pattern in stacked heeled shoes and suddenly try a zero drop shoe you better be aware of symptoms such as pain, tightness or other complications.  Is your body able to adapt to a new (possibly increased) ankle-midfoot rocker or the demand of a greater ankle-midfoot with the newly dropped heel? Is your body immediately adaptive enough after going through that stage of gait with the heel higher than the forefoot for years ?  Just because you went to a running form clinic doesn’t mean  you are ready to make that your new form tomorrow. Change takes time, so be patient with your body and let it adapt.

Food for thought, especially for those who say to others. “Hey dude, chuck your ramped shoes and go minimialism or barefoot. Just go for it. I did and I was fine !”

What is fine for one, is not fine for all.

Shawn and Ivo

The Gait Guys

Podcast #17: Gait and Magic (and much more !)

Podcast Link:

http://thegaitguys.libsyn.com/podcast-17-magic-gait

iTunes link:

https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138

__________________________________________________________

Gait, Magic, Evolution, Foot Types, Stretching, Cases studies…… we have it all on today’s podcast.

Show Links
“How does the brain work ?”
 Nova Science Now
www.video.pbs.org   

buy this NOVA program now ! Educate the world ! :
http://www.shoppbs.org/product/index.jsp?productId=11095035&utm_source=PBS&utm_medium=Link&utm_content=nosn_nova6215_howbrainworks_covebuyit&utm_campaign=cove_buyit

Other links for today’s show:

http://www.medlink.com/medlinkcontent.asp

http://www.ncbi.nlm.nih.gov/pubmed/12763089

http://www.ajronline.org/content/184/3/953.full

1. Hi Guys,
I was wondering if you could direct me to a podcast/video or elaborate on how a fast stretch can relax a hypertonic muscle in a practical setting. Can manual stretching techniques like MET be use by altering the technique with a short fast stretch or are you just referring to high velocity low amplitude manipulation? We are often taught to find the barrier apply contraction and then ‘gently’ go to the next barrier. Is this still a good way of activating the GTO’s?Also do you have any further discussion I can check out on GTO’s?

Thanks for your time, Adrian

2. Hello, GAIT Guys!

First I want to thank you for your phenomenal work!
I work alot with athletes and there are so many that have some sort of sole into their shoes. Problem was, pretty much everyone, didn’t get the answer to WHY they needed them. Just the normal “your foot pronates” and frankly, 1 out of 40 got better.
I was driven by the question WHY, searched around in Sweden, attending lectures, orthophaedic clinics etc, but I didn’t get the answers that I was looking for.
Started to look into it deeper for myself, when I found you guys!
Now I want to bring back that knowledge to Sweden, cause frankly.. WE NEED IT!
Can you tell me more about your certification? Is it possible for a Swe to attend and get the certification?
Best Regards
Gabriel
Dr. of Naprapathy from Sweden

3. Hello Drs. Waerlop and Allen. I need some clarification on gait biomechanics. Will using a more “minimalist” running shoe or a shoe with less RF to FF delta help peroneous longus to gain mechanical advantage? If someone has a forefoot varus would recommending a lower ramp shoe be appropriate to help “retrain” the tripod at stance phase? 
John F

4. Another blog question…ivo said in podcast #15 that most people have a forefoot abnormality (during section talking about flares). Any idea Why? Is it skewed toward one way or the other?
After looking at quite a few feet since becoming shoe fit certified, I’ve noticed quite a lot of variation. If I was pressed if say I’ve seem <10% FF valgus and maybe half of the rest each neutral and varus. Is that in the ballpark of what you guys see?
How about rear foot? I feel like I see a lot of rear foot varus but maybe my frame of reference is not accurate? If I was pressed, I’d say 70% varus, 29% neutral, 1% valgus. Does that seem off?
Thanks, Eric J

Category
Educational

More on the “Earth” shoe

3.7 degrees. Who (besides maybe Kevin Bacon) would have thought a few degrees could make that much of a difference?

We don not doubt that the shoe helps you to burn more energy. You are walking up hill against your normal biomechanics. Inefficiency usually costs more energy.

Remember our friend “PRONATION”? It consists of dorsiflexion, eversion and abduction. SOME PRONATION is requisite for normal gait. It is one of the 4 shock absorbing mechanisms, along with ankle dorsiflexion, knee and hip flexion. (Midfoot) PRONATION begins from initial contact of the heel with the ground (loading response); friction of the heel on the ground causes the talus to slide anteriorly on the calcaneus and it then plantar flexes, adducts and everts to lower the midfoot. This goes on until MIDSTANCE, when the opposite leg begins to go into swing phase which initiates SUPINATION.

We remember PRONATION makes the foot into a “mobile adaptor” for shock absorbtion; SUPINATION makes the foot into a rigid lever for propulsion. The question is: “Why keep the foot in a position that would decrease biomechanical efficiency for 1/2 of the gait  cycle?”

We do not refute that the shoe does burn more energy. We agree that it will reduce the lordosis of the low back, which can be beneficial for spinal canal stenosis and a few other conditions which demand less stress on the facet joints. We like the wide (though not anatomic) toe box.

Negative ramp delta? We are not convinced this is great idea.

Ivo and Shawn. Triangular, pointy (but beautifuul and bald) heads (like a delta). Bringing you the facts so you can make better decisions.

More on the “Earth” shoe

3.7 degrees. Who (besides maybe Kevin Bacon) would have thought a few degrees could make that much of a difference?

We don not doubt that the shoe helps you to burn more energy. You are walking up hill against your normal biomechanics. Inefficiency usually costs more energy.

Remember our friend “PRONATION”? It consists of dorsiflexion, eversion and abduction. SOME PRONATION is requisite for normal gait. It is one of the 4 shock absorbing mechanisms, along with ankle dorsiflexion, knee and hip flexion. (Midfoot) PRONATION begins from initial contact of the heel with the ground (loading response); friction of the heel on the ground causes the talus to slide anteriorly on the calcaneus and it then plantar flexes, adducts and everts to lower the midfoot. This goes on until MIDSTANCE, when the opposite leg begins to go into swing phase which initiates SUPINATION.

We remember PRONATION makes the foot into a “mobile adaptor” for shock absorbtion; SUPINATION makes the foot into a rigid lever for propulsion. The question is: “Why keep the foot in a position that would decrease biomechanical efficiency for ½ of the gait  cycle?”

We do not refute that the shoe does burn more energy. We agree that it will reduce the lordosis of the low back, which can be beneficial for spinal canal stenosis and a few other conditions which demand less stress on the facet joints. We like the wide (though not anatomic) toe box.

Negative ramp delta? We are not convinced this is great idea.

Ivo and Shawn. Triangular, pointy (but beautifuul and bald) heads (like a delta). Bringing you the facts so you can make better decisions.