Leg length discrepancies and total joint replacments.

5mm cut off ?  MaybeYou are likely to come across hip and knee arthroplasty clients (total joint replacements). When they take a joint out and replace it with a new one, it can be a true challenge to restore leg lengths to equality side to side. Problems often arise down the road once gait is resumed and rehabilitation is completed. It can take time for the leg length discrepancy (LLD) to begin to create compensatory problems. This article seems to suggest that 5mm is the tipping point where gait changes becoming a problem are founded. Other sources will render different numbers, this article found 5mm. The authors found that both over- and underrestoration of leg length/offset showed similar effects on gait and that Gait analysis was able to assess restoration of biomechanics after hip replacement.  I would chose to use the word “change” over restore, since the gait analysis is merely showing the deployed strategies and compensations, never the problem.  But it is a tool, and gait analysis can be a decent tool to show “change”.*Remember, it is not always a product of true length, it can come from the pelvis posturing and/or from the acetabular orrientation, which can be a postoperative sequella. One cannot over look  acetabular inclination, anteversion and femoral component anteversion/retroversion issues.Just remember, before you start making LLD changes with inserts, cork, orthotics etc be sure that you have restored as best as possible, pelvis-hip-spine mechanics because changes here can reflect as a mere leg length discrepancy. And it goes the other way as well, a LLD can cause those changes above.

* Just use your brain and don’t just lift the heel, give them a full sole lift. Heel lifts for this problem are newbie mistakes. Don’t be a newbie.

– Dr. Shawn Allen

Leg length and offset differences above 5 mm after total hip arthroplasty are associated with altered gait kinematicsTobias Renkawitz, Tim Weber, Silvia Dullien, Michael Woerner, Sebastian Dendorfer, Joachim Grifka,Markus Weber
http://www.gaitposture.com/article/S0966-6362(16)30148-5/abstract?platform=hootsuite

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.

Podcast 91: Gait, Vision & some truths about leg length discrepancies

Show sponsors:
www.newbalancechicago.com

A. Link to our server:
http://traffic.libsyn.com/thegaitguys/pod_91f.mp3

Direct Download:
http://thegaitguys.libsyn.com/91

Other Gait Guys stuff

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

C. Gait Guys online /download store (National Shoe Fit Certification and more !) :
http://store.payloadz.com/results/results.aspx?m=80204

D. other web based Gait Guys lectures:
Monthly lectures at : www.onlinece.com   type in Dr. Waerlop or Dr. Allen,  ”Biomechanics”

Our Book: Pedographs and Gait Analysis and Clinical Case Studies

electronic copies available here:

Amazon/Kindle:

http://www.amazon.com/Pedographs-Gait-Analysis-Clinical-Studies-ebook/dp/B00AC18M3E

Barnes and Noble / Nook Reader:

http://www.barnesandnoble.com/w/pedographs-and-gait-analysis-ivo-waerlop-and-shawn-allen/1112754833?ean=9781466953895

https://itunes.apple.com/us/book/pedographs-and-gait-analysis/id554516085?mt=11

Hardcopy available from our publisher:

http://bookstore.trafford.com/Products/SKU-000155825/Pedographs-and-Gait-Analysis.aspx

Show notes:

Gait and vision: Gaze Fixation
What’s Up With That: Birds Bob Their Heads When They Walk
http://www.wired.com/2015/01/whats-birds-bob-heads-walk/
 
Shod vs unshod
 
Short leg talk:
11 strategies to negotiate around a leg length discrepancy

From a Reader:

Dear Gait Guys, Dr. Shawn and Dr. Ivo,  I was referred to this post of yours on hip IR…http://thegaitguys.tumblr.com/post/14262793786/gait-problem-the-solitary-externally-rotated   I am impressed by the level of details of your understanding of the gait and biomechanics. Although I am still trying to understand all of your points in this post, I would like to ask you:  What if my IR is limited due to a structural issue? The acetabular retroversion of the right hip in my case. 

I.e. if I am structurally unable to rotate the hip internally.
What will happen? 
What would be a solution to the problem in that case? 

Single-leg drop landing movement strategies 6 months following first-time acute lateral ankle sprain injury – Doherty – 2014 – Scandinavian Journal of Medicine & Science in Sports
http://onlinelibrary.wiley.com/doi/10.1111/sms.12390/abstract

Hey Gait Guys,

I understand that 1st MP Joint dorsiflexion, ankle rocker, and hip extension are 3 key factors for moving in the sagittal plane from your blog and podcasts so far. I really love how you guys drill in our heads to increase anterior strength to increase posterior length to further ankle rocker. I’ve seen the shuffle gait and was curious if you had a good hip extension exercise to really activate the posterior hip extensors and increase anterior length. 

Podcast 36: Heel lift lies, the Exercise Drug & Malcolm Gladwell’s 10,000 hours.

http://thegaitguys.libsyn.com/podcast-36-heel-lift-lies-and-the-exercise-drug

iTunes link:

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

Gait Guys online /download store:

http://store.payloadz.com/results/results.aspx?m=80204

other web based Gait Guys lectures:

www.onlinece.com   type in Dr. Waerlop or Dr. Allen  Biomechanics

Today’s show notes:

Neuroscience piece:

Description
1. Health Scanner Scanadu Scout: the future of medical info gathering ?

2. The Exercise Drug:

www.gizmag.com/scripps-drug-sr9009-exercise-mimic/28651

3. FB reader sent us a message:

 am posting this to see if I can get a little bit of help from the best professionals in the area (you). 

I have read some of the information on your site and I think I have quite a problem on my right foot. It happens that the medial part of the foot tripod does not touches the floor at all and I have lack of support in that zone. So it seems like my forefoot is varus. I have also noticed that when I am standing it looks like my rear foot is valgus. So, I can’t really compensate this problem because if the forefoot is varus and I try to put it neutral, the rear foot gets even more valgus, and if it I try to put the rear foot neutral, the forefoot gets even more varus and my big toe does not touch any part of the floor. Can you please help me? I do not know what to do and I am a little bit desperate because nobody I went to could help me. You are probably my last hope. I know I can correct this and I have the will and dedication to pull it off. I bet there are some exercises I can do but I do not really know which at all. 
Thanks in advance. -Jorge

4. Another TUMBLR reader asks question about
Guys what are the possible muscular causes of genu varum during initial swing?
5. Another off tumblr:  Anything  you can talk about on this topic ?
How does running in low-to-no light conditions effect your gait/running/injuries/etc?
6. Topic: step  width

Changing step width alters lower extremity biomechanics during running

7.  heel lift vs. sole lift
why and when would you use only a heel lift…..unilaterally ?
8. National Shoe Fit program: 
Link: http://store.payloadz.com/results/results.aspx?m=80204
9. Questions from a field doc:
Hey guys,

 I have heard you guys say many times that many people who choose to venture into minimalistic footwear have not “earned their right” to do such without increasing their risk for problems.  I was wondering if you could explain what parameters you use to determine if and when they are ready.  
Thanks,
Ryan 
10. Shoes: does pronation matter
11. Shoes #2:
12. Malcolm Gladwell debate, 10,000 hours

Podcast 36: Heel lift lies, the Exercise Drug & Malcolm Gladwell’s 10,000 hours.

http://thegaitguys.libsyn.com/podcast-36-heel-lift-lies-and-the-exercise-drug

iTunes link:

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

Gait Guys online /download store:

http://store.payloadz.com/results/results.aspx?m=80204

other web based Gait Guys lectures:

www.onlinece.com   type in Dr. Waerlop or Dr. Allen  Biomechanics

Today’s show notes:

Neuroscience piece:

Description
1. Health Scanner Scanadu Scout: the future of medical info gathering ?

2. The Exercise Drug:

www.gizmag.com/scripps-drug-sr9009-exercise-mimic/28651

3. FB reader sent us a message:

 am posting this to see if I can get a little bit of help from the best professionals in the area (you). 

I have read some of the information on your site and I think I have quite a problem on my right foot. It happens that the medial part of the foot tripod does not touches the floor at all and I have lack of support in that zone. So it seems like my forefoot is varus. I have also noticed that when I am standing it looks like my rear foot is valgus. So, I can’t really compensate this problem because if the forefoot is varus and I try to put it neutral, the rear foot gets even more valgus, and if it I try to put the rear foot neutral, the forefoot gets even more varus and my big toe does not touch any part of the floor. Can you please help me? I do not know what to do and I am a little bit desperate because nobody I went to could help me. You are probably my last hope. I know I can correct this and I have the will and dedication to pull it off. I bet there are some exercises I can do but I do not really know which at all. 
Thanks in advance. -Jorge

4. Another TUMBLR reader asks question about
Guys what are the possible muscular causes of genu varum during initial swing?
5. Another off tumblr:  Anything  you can talk about on this topic ?
How does running in low-to-no light conditions effect your gait/running/injuries/etc?
6. Topic: step  width

Changing step width alters lower extremity biomechanics during running

7.  heel lift vs. sole lift
why and when would you use only a heel lift…..unilaterally ?
8. National Shoe Fit program: 
Link: http://store.payloadz.com/results/results.aspx?m=80204
9. Questions from a field doc:
Hey guys,

 I have heard you guys say many times that many people who choose to venture into minimalistic footwear have not “earned their right” to do such without increasing their risk for problems.  I was wondering if you could explain what parameters you use to determine if and when they are ready.  
Thanks,
Ryan 
10. Shoes: does pronation matter
11. Shoes #2:
12. Malcolm Gladwell debate, 10,000 hours