Are old running shoes detrimental to your feet? Here is some research.

Are old running shoes detrimental to your feet? A pedobarographic study.

by: Rethnam U, Makwana N.

STUDY BACKGROUND: “Footwear characteristics have been implicated in fatigue and foot pain. The recommended time for changing running shoes is every 500 miles. The aim of our study was to assess and compare plantar peak pressures and pressure time integrals in new and old running shoes.”

CONCLUSION:

“Plantar pressure measurements in general were higher in NEW running shoes. This could be due to the lack of flexibility in new running shoes. The risk of injury to the foot and ankle would appear to be higher if running shoes are changed frequently. We recommend breaking into new running shoes slowly using them for mild physical activity.”

What do The Gait Guys say ? Did you read our post yesterday on this very topic ? Here is the link.  Never let a pair of shoes get too old before breaking in a new pair. The old shoes can be just as much of a problem as the new shoes.  Old shoes break down the foam into possible detrimental biomechanical patterns that can promote overstress to areas and create injury. A new shoe can be stiffer and thus change your biomechanics away from what is clean function for you.

So what is the solution ? If you read our blog post yesterday you know the answer (see #5 in yesterday’s blog post). LINK  (Blog post December 5th, 2012).

Shawn and Ivo, The Gait Guys

BMC Res Notes. 2011 Aug 24;4:307.

Are old running shoes detrimental to your feet? A pedobarographic study.

Source

Department of Orthopaedics, Glan Clwyd Hospital, Rhyl, UK. ulfinr@yahoo.com.

http://www.ncbi.nlm.nih.gov/pubmed/21864342

Do you have enough Ankle Dorsiflexion to do this ?  Some clues ?

Two guys pulling 40,000 pounds over one mile in just over an hour !

Watch the video above and then check out this link.

http://www.powerropes.com/brtrophy.html

Look at the fellas left foot in the video compared to his right.  Notice the turn out (the increased progression angle as it is referred to as) ?  Now look at the photos from the article link above, again the fella in the red shirt has his left foot turned out again.  Why is he doing this ? 

Because he does not likely have enough ankle dorsiflexion (ankle rocker) to get into this far of a forward lean.  Have you seen this in people or your students doing squats ? Lunges ? Will this present in his normal gait ? Perhaps, but if he has enough for normal gait (~15 degrees past vertical 90 degrees) he shouldn’t need to turn it out.

Turning out the foot will allow you to pronate through the midfoot to gain more dorsiflexion. It is why some people do it.  Look for it.

It is also possible that he has a painful big toe or a hallux rigidus/limitus (ie. turn toe) and thus cannot toe off sagittally like on the other foot or like the other fella.  This turn out will avoid loading that joint as much. 

Regardless, you must examine this fella and figure out why he is using this strategy only on one side.  This is just one theory, but we did not want to pollute this post with a few others. We can do that another time.

Ankle rocker dorsiflexion. It is critical for some activities.

Shawn and Ivo

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from a FAcebook reader:

  • Question:  Most sources allow for a small amount of turnout as “normal” in gait – about 7 degrees on average. Should feet point straight ahead? What is the repercussion of turnout, even a small amount? I think in barefoot societies the feet are pointing straight ahead so I wondered where this belief comes from and if it is correct. Perhaps people are losing dorsiflexion from wearing positive heels and are turning out in response? Thanks.

  • The Gait Guys You are correct. zero degrees progression angle is not considered normal….. 5-20 degrees is more “normal”……but it depends on the source. Keep in mind that femoral torsion and tibial torsion will be big players in this foot angle. The more the foot is turned out the more pronation (more than normal) can sneak in. IT will challenge the foot tripod. Weakness in the glutes, (particlarly g. medius from frontal plane challenges ) may ask the limb and foot to turn out to engage a more stable foot tripod. meaning, if you engage another plane (ie. more frontal plane) via more foot/limb turn out you can gain the help from other muscles such as the quadriceps. Reducing the heel height can force one to adapt to the use of more ankle dorsiflexion, you are correct. Hence why the literature suggests less injuries from more minimialist shoes. Hope this helps.

Is Your Foot Tripod Stable Enough to Walk or Run without Injury or Problem ?

The all to common case of the Wobbling Tripod.

Note the music we have chosen today. We tried to match the rate of the dancing tibialis anterior tendon to the tempo of the song, just for fun of course. Well, actually, for neurological reasons as well, as with a steady tempo or beat, your nervous system can learn better. Why do you think we teach kids songs to learn (or you can’t get the theme from the “Jetsons” out of your head).

This is a great video. This client has an obvious problem stabilizing the foot tripod during single leg stance as seen here.  There is also evidence of long term tripod problems by the degree of redness and size (although difficult to see on this plane of view) of the medial metatarsophalangeal (MTP) joint (the MPJ or big knuckle joint) just proximal to the big toe.  This is the area of the METatarsal head, the medial aspect of the foot tripod.

As this client moves slowly from stance into a mild single leg squat knee bend the challenges to the foot’s stability, the tripod, become obvious.  Stability is under duress. There is much frontal plane “Checking” or shifting and the tibial and body mass is rocking back and forth on a microscopic level as evidenced by the dancing tibialis tendon at the ankle level.  The medial foot tripod is loading and unloading multiple times a second. 

Is it any shock to you that this person has chronic foot problems which are exacerbated by running ?  Every time this foot hits the ground the foot is trying to find stability. The medial tripod fails and the big knuckle joint (the 1st MPJ or big toe joint) is enlarging from inflammation and early cartilage wear and decay, not to mention the knee falling medially as well!  Hallux limitus (turf toe) is subclinical at this time, but it is on the menu for a later date. A dorsal crown of osteophytes (the turf toe ridge on the top of the foot) is developing steadily, soon to block out the range necessary for adequate toe off in this client.  And that means a limitation in  hip extension sometime down the road (and premature heel rise……. did you read Wednesday’s blog post on that topic ?).

*addendum:

Take the time to develop the skill. We ask our clients to work on standing with the toes up to find a clean tripod and do some shallow squats working on holding the tripod quietly. Be sure your glutes are in charge. Then, again using the toes pressed flat but be sure the tripod is still valid, esp the medial tripod. No toe curling/hammering. Keep that glute on. Move the swing leg forward during a squat, and then behind you during a squat (mimicing early and late midstance phases of gait/running). This will help your brain realize when it needs this stability and it will also act to press you off balance and will make the foot check and challenge. Do this until you feel the foot fatigue on the bottom. Then Stop. Repeat later. If the medial tripod collapses, the knee will drop inwards and excess pronation is inevitable. We modified this with our prescription of the “100 ups”…..combine the two !

Shawn and Ivo … .  comfortably numb.

Once you have been to the Dark Side of the Moon  (and hopefully you didn’t have any Brain Damage) you will know it well and know what to expect when you return again.  Meaning, when you have seen these issues over and over again, hopefully in your daily work if not regularly here at The Gait Guys, you will quickly know what things to assess and look for in your athletes.  And you might just turn into a Pink Floyd fan at the same time, or at least crave some Figgy Pudding (but you have to eat yer’ meat! How can you have any pudding if you don’t eat  yer’ meat?).