Do you know where your rocker is?

At 1st pass, some articles may seem like a sleeper, but there can be some great clinical pearls to be had. I recently ran across one of these. It was a presentation from the  42nd annual American Academy of Orthotists and Prosthetists meeting in Orlando, March 2016 entitled “ Shifting Position of Shoe Heel Rocker Affects Ankle Mechanics During Gait”. The title caught my eye.

They looked at ankle kinematics while keeping the toe portion of rocker constant at 63% of foot length, angled at 25 degrees and shifting the base of a rockered shoe from 1cm behind the medial malleolus, directly under it and 1cm anterior to it. Knee and hip kinematics did not differ significantly, however ankle range of motion did.

The more forward the ankle rocker, the less plantarflexion but more ankle dorsiflexion at midstance. So, the question begs, why do we care? Lets explore that further…

  • Think about the “average” heel rocker in a shoe. It largely has to do with the length of the heel and heel flare (base) of the shoe. The further back this is (ie; the more “flare”) the more plantar flexion at heel strike and less ankle dorsiflexion (and thus ankle rocker, as described HERE) you will see. Since loss of ankle dorsiflexion (ie: rocker) usually means a loss of hip extension (since these 2 things should be relatively equal during gait (see here), and that combination can be responsible for a whole host of problems that we talk about here on the blog all the time. Picking a shoe with a heel rocker based further forward (having less of a flare) would stand to promote more ankle dorsiflexion.
  • Having a shoe with a greater amount of “drop” from heel to toe (ie: ramp delta) is going to have the same effect. It will move the calcaneus forward with respect to the heel of the shoe and effectively move the rocker posteriorly.
  • Lastly, look a the shape of the outsole of the shoe. The toe drop is usually clear to see, but does it have a heel rocker (see the picture above)?

These are  a few examples of what to look for in a clients shoe when examining theirs or making a recommendation, depending on whether you are trying to improve or decrease ankle rocker. We can’t think of why you would want to decrease ankle rocker, but with conditions like rigid hallux limitus, where the person has limited or no dorsiflexion of the great toe, you may want to employ a rockered sole shoe. We would recommend one with the rocker set more forward.

Here is another nice review. Consider Sever’s with all your younger heel pain patients

We posted on this a few weeks ago. see here:http://thegaitguys.tumblr.com/…/clinical-tidbit-heel-pain-i…

Zero Drop? Think before you drop. More to think about before you make the jump (or run, or walk or stand…)

Ramp Delta. Drop. Heel to toe differential. Stack height differential. You have likely heard all the words before. We are talking about the difference in height between the center of the heel and ball of the big toe on the foot. It is literally “how much heel” the shoe has. Some have upwards of 20mm, some none at all (zero drop). The average seems to be 10-15 mm for many shoes, but that tradition is evolving to less and less (Brooks for example now has the “Pure” Series with a 4 mm average and one shoe that can be either 4 or zero (The Drift)). New Balance has their miniumus, Altra has their army of shoes, Saucony has a variable selection. Everyone is on target with their collection of minimalist or minimalist-trending (or as we like to call them, “gateway”) shoes.

Since we are born “sans” shoes, zero seems “natural” or maybe the best, right? Maybe, maybe not. A lot depends on you and your anatomy however logic dictates that we were born with the rear and forefoot on the same plane so there has to be a natural logic to the zero drop trend. The problem remains, how long have you been forcing this non-natural state and how long (if at all) will you be able to return to the “less is more” trend?

If you have been in shoes with more drop your whole life, your musculoskeletal system and neurology has adapted to that. If we take away our favorite chair, pair of shoes, golf club or whatever, you may have something to say about it. Same for your feet. If you drop/lower your heel, there are biomechanical changes and possible consequences.

You may have read this weeks post, talking about having enough ankle range of motion available. Dropping the heel requires more dorsiflexion (or extension) of the ankle. If that range of motion is not available, then the motion needs to occur somewhere else.

So, where elsewhere in the body is the motion going to occur ? Dropping the ankle requires more knee extension. Do you have that range of motion available? Are your knees painful when you wear a zero drop shoe?

How about your hips? Dropping the heel requires more hip extension as well. This extension is often accompanied by internal rotation of the hip (ankle dorsiflexion, along with foot abduction and forefoot eversion are all components of pronation, which will cause medial rotation of the hip. Do you have this range of motion available, or do you have femoral retro torsion, and a zero drop shoe makes that worse?

What about the effect on the low back? Dropping the heel decreases the lumbar lordosis (the natural curve forward). Don’t believe us ? Just look at any woman in a 3 inch pump and you will see some lovely curves. This places additional stress on the posterior ligaments and joint capsules and compression and shear on the discs. Some spines won’t tolerate this, just like some won’t tolerate heels, which increases the lumbar lordosis and places more stress on the posterior joints.

What about the mid back? Dropping the heel decreases the thoracic curve. How much extension (backward movement) do you have in your mid back?

The same with the neck…and the list goes on….

As you can see, it is much more complex than just changing to a shoe with less drop. Because of the biomechanical changes and demands, it will probably cost you something, be it range of motion, comfort, function. We are not saying it isn’t worth it, or that you shouldn’t do it; we are saying go slow and listen to your body. What may be right for someone else may not be right for you … . either in the short or long term.

Earn your way. Don’t throw caution to the wind. We see people everyday that have suffered the above consequences due to listening to the wonderful marketing of the minimalist trend and from embracing some of the nonsense on the web.  We call these people, “patients”.  Don’t make yourself a patient, use your head when it comes to your feet.

The Gait Guys

Ivo and Shawn

All material copyright 2013 The Gait Guys/ The Homunculus Group. All rights reserved. Please ask before lifting our material.

Zero Drop? Think before you drop. More to think about before you make the jump (or run, or walk or stand…)

Ramp Delta. Drop. Heel to toe differential. Stack height differential. You have likely heard all the words before. We are talking about the difference in height between the center of the heel and ball of the big toe on the foot. It is literally “how much heel” the shoe has. Some have upwards of 20mm, some none at all (zero drop). The average seems to be 10-15 mm for many shoes, but that tradition is evolving to less and less (Brooks for example now has the “Pure” Series with a 4 mm average and one shoe that can be either 4 or zero (The Drift)). New Balance has their miniumus, Altra has their army of shoes, Saucony has a variable selection. Everyone is on target with their collection of minimalist or minimalist-trending (or as we like to call them, “gateway”) shoes.

Since we are born “sans” shoes, zero seems “natural” or maybe the best, right? Maybe, maybe not. A lot depends on you and your anatomy however logic dictates that we were born with the rear and forefoot on the same plane so there has to be a natural logic to the zero drop trend. The problem remains, how long have you been forcing this non-natural state and how long (if at all) will you be able to return to the “less is more” trend?

If you have been in shoes with more drop your whole life, your musculoskeletal system and neurology has adapted to that. If we take away our favorite chair, pair of shoes, golf club or whatever, you may have something to say about it. Same for your feet. If you drop/lower your heel, there are biomechanical changes and possible consequences.

You may have read this weeks post, talking about having enough ankle range of motion available. Dropping the heel requires more dorsiflexion (or extension) of the ankle. If that range of motion is not available, then the motion needs to occur somewhere else.

So, where elsewhere in the body is the motion going to occur ? Dropping the ankle requires more knee extension. Do you have that range of motion available? Are your knees painful when you wear a zero drop shoe?

How about your hips? Dropping the heel requires more hip extension as well. This extension is often accompanied by internal rotation of the hip (ankle dorsiflexion, along with foot abduction and forefoot eversion are all components of pronation, which will cause medial rotation of the hip. Do you have this range of motion available, or do you have femoral retro torsion, and a zero drop shoe makes that worse?

What about the effect on the low back? Dropping the heel decreases the lumbar lordosis (the natural curve forward). Don’t believe us ? Just look at any woman in a 3 inch pump and you will see some lovely curves. This places additional stress on the posterior ligaments and joint capsules and compression and shear on the discs. Some spines won’t tolerate this, just like some won’t tolerate heels, which increases the lumbar lordosis and places more stress on the posterior joints.

What about the mid back? Dropping the heel decreases the thoracic curve. How much extension (backward movement) do you have in your mid back?

The same with the neck…and the list goes on….

As you can see, it is much more complex than just changing to a shoe with less drop. Because of the biomechanical changes and demands, it will probably cost you something, be it range of motion, comfort, function. We are not saying it isn’t worth it, or that you shouldn’t do it; we are saying go slow and listen to your body. What may be right for someone else may not be right for you … . either in the short or long term.

Earn your way. Don’t throw caution to the wind. We see people everyday that have suffered the above consequences due to listening to the wonderful marketing of the minimalist trend and from embracing some of the nonsense on the web.  We call these people, “patients”.  Don’t make yourself a patient, use your head when it comes to your feet.

The Gait Guys

Ivo and Shawn

All material copyright 2013 The Gait Guys/ The Homunculus Group. All rights reserved. Please ask before lifting our material.

A blast from the past. Here’s one of our favorite posts, just in case you missed us a few years ago…

More Gait Guy Gait Gaffs: What it would look like if “The Flash”, ran with heel strike ? click here. Note the excellent anterior compartment use (nice ankle dorsiflexion and toe extension at terminal swing/ pre-impact) but heavy, nasty, heel strike. What is interesting here is that he has adopted a nice forward lean (ala. natural or chi running style) but when combining this with a heel strike gait you end up with an anterior pelvic tilt (which begins inhibition of the lower abdominals) and you then have to begin the power through phase in early-mid stance phase with the hamstrings. You need tremendous lower abdominal strength, and hamstring length and strength to run this way (go ahead, get up and try it running through your office ! let out a great “Yaulp” from the ensuing hamstring pull (ala Robin Willliams in Dead Poets Society) when you find out your abdominals are not strong enough to lean that far forward and still heel strike, without enough hamstring length (on second thought, just trust  us……although i know now we have challenged some of you). This is a medical disclaimer, dont do it !

Looks like Newbies are heel strikers

“Nearly all novice runners utilize a rearfoot strike when taking up running in a conventional running shoe. Hereby, the footstrike patterns among novice runners deviate from footstrike patterns among elite and sub-elite runners.”


please take some time to explore the links we put in, as they are germane to the post


The question begs, “Why?”

  • do they believe running is merely an extension of walking, and just “speed up” the process?
  • are they afraid of going too fast and are using the heel strike to “brake”?
  • do they learn to strike differently with more experience? at least one paper eludes to “yes”
  • is it “more comfortable” as this paper says it may be?
  • If there is a rear foot strike, the foot is poised to be able to pronate to a greater degree. This theoretically means it (ie, the foot) can absorb more shock through this mechanism, although this seemingly contradicts the Lieberman study

This paper certainly had a nice cohort size (> 900 runners) so we can state, at least for this group, that this is not by chance.  When there is a fore foot strike, the foot is more supinated and makes a seemingly “rigid lever”, does this mean there is less shock (perceived or actual) with this foot posture?

Lots of questions. This is only 1 part of the puzzle.

The Gait Guys. Sifting through the literature and giving you the beef

            

Gait Posture. 2012 Dec 29. pii: S0966-6362(12)00448-1. doi: 10.1016/j.gaitpost.2012.11.022. [Epub ahead of print]

Footstrike patterns among novice runners wearing a conventional, neutral running shoe.

Bertelsen ML, Jensen JF, Nielsen MH, Nielsen RO, Rasmussen S.

Aarhus University Hospital, Aalborg Hospital, Orthopaedic Surgery Research Unit, Science and Innovation Center, Aalborg DK-9000, Denmark. Electronic address: miclejber@gmail.com.

Abstract

INTRODUCTION:

It has been suggested that striking on the midfoot or forefoot, rather than the rearfoot, may lessen injury risk in the feet and lower limb. In previous studies, a disparity in distribution in footstrike patterns was found among elite-, sub-elite, and recreational runners.

PURPOSE:

The purpose of this study was to investigate the footstrike patterns among novice runners.

METHODS:

All runners were equipped with the same conventional running shoe. Participants were video filmed at 300 frames per second and the footstrike patterns were evaluated by two observers. The footstrike was classified as rearfoot, midfoot, forefoot, or asymmetrical.

RESULTS:

A total of 903 persons were evaluated. The percentages of rearfoot-, midfoot-, forefoot-, and asymmetrical footstrike among men were 96.9%, 0.4%, 0.9%, and 1.8%, respectively. Among women the percentages were 99.3%, 0%, 0%, and 0.7%, respectively.

CONCLUSION:

Nearly all novice runners utilize a rearfoot strike when taking up running in a conventional running shoe. Hereby, the footstrike patterns among novice runners deviate from footstrike patterns among elite and sub-elite runners.

Copyright © 2012 Elsevier B.V. All rights reserved.

PMID: 23280125 [PubMed – as supplied by publisher]



all material copyright 2013 The Gait Guys/The Homunculus group. Please don’t lift our stuff without asking and giving credit.

High Heels and …..Orthotics?

What better way to end the year than to talk about something that some of you have worn last evening. Not only clean underwear, but also high heels!

You have heard all about high heels here on the blog (if not, click here). Now here is some info that may be surprising! This study found that increased heel height caused increased plantar pressures (no surprises) BUT the use of an orthotic or arch pad, attenuated impact forces. IOHO not a reason to wear heels (though we DO like the way they look : )) but if you need to wear them (really? you need to wear them?), then maybe consider an insert to make it more bearable.

Ivo and Shawn                                              

                           

Appl Ergon. 2005 May;36(3):355-62.

Effects of shoe inserts and heel height on foot pressure, impact force, and perceived comfort during walking.

Source

Department of Industrial Management, National Taiwan University of Science and Technology, No. 43, Kee-Lung Road, Sec IV, Taipei, Taiwan, 106 ROC. yhlee@im.ntust.edu.tw

Abstract

Studying the impact of high-heeled shoes on kinetic changes and perceived discomfort provides a basis to advance the design and minimize the adverse effects on the human musculoskeletal system. Previous studies demonstrated the effects of inserts on kinetics and perceived comfort in flat or running shoes. No study attempted to investigate the effectiveness of inserts in high heel shoes. The purpose of this study was to determine whether increasing heel height and the use of shoe inserts change foot pressure distribution, impact force, and perceived comfort during walking. Ten healthy females volunteered for the study. The heel heights were 1.0cm (flat), 5.1cm (low), and 7.6cm (high). The heel height effects were examined across five shoe-insert conditions of shoe only; heel cup, arch support, metatarsal pad, and total contact insert (TCI). The results indicated that increasing heel height increases impact force (p<0.01), medial forefoot pressure (p<0.01), and perceived discomfort (p<0.01) during walking. A heel cup insert for high-heeled shoes effectively reduced the heel pressure and impact force (p<0.01), an arch support insert reduced the medial forefoot pressure, and both improved footwear comfort (p<0.01). In particular, a TCI reduced heel pressure by 25% and medial forefoot pressure by 24%, attenuate the impact force by 33.2%, and offered higher perceived comfort when compared to the non-insert condition.