Podcast 52: Limb Dominance & Other Cool Stuff

A. Link to our server:


B. iTunes link:


C. Gait Guys online /download store (National Shoe Fit Certification and more !) :


D. other web based Gait Guys lectures:

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


* Today’s show notes:


1. The Potential Downside of Wearable Biomechanical Monitoring Devices for Running


2. Google’s Next Crazy Project: Smart Contact Lenses | Entrepreneur.com

3. How Humans Burn Fewer Calories Than Other Mammals


4. Update: I was listening to your podcast and you said Ice Bug was out of business. I sell them in my store in Fairbanks Alaska where we have snow and ice on the ground for 6-7 months a year. The US distributor is Ice Bug USA. I also carry a the Salomon Snow Cross studded shoe.
The effects of limb dominance and fatigue on running biomechanics
5. Email case:
Dear Gaitguys,
   I have been on a search since October to determine the cause of my chronic tendonitis in my knees and right hip. Through my search I was told that my femurs are rotated internally and my tibia are externally rotated. This is causing my patella to face inward.
  I was told by one PT that I will never be able to run long distances without developing tendonitis. I want to believe he is wrong because I love running. I came across something called Femoral Anterior Glide in my research and was wondering if you guys believe this is a real condition. Also is there a way a person can know if they have this problem?
Thank you for all of your great posts!
6. Blog reader:

My 11 year old son walks with a very noticeable external tibial torsion. We just recently noticed this and I came upon your site while trying to research it. I also read that many time it has to do with a problem with the patella. Both my husband and daughter have had patella problems but do not have the duck walk like my son. I did ask a a pediatric sports medicine specialist about the problem and he said some kids just walk that way. Where should I bring my son for help with this?

7. Blog reader asks:

About a year ago there was an article posted called: “A case of the non-resolving ankle sprain. Things to think about when the ankle and foot just do not fully come around after a sprain”. I am 15 weeks into an identical problem and I was wondering if there was any way you guys could follow up with “MR” to see if he was ever able to resolve his issue. It is such a unique and frustrating case (being able to walk but not run) and I haven’t found any other instance of it until now. Thank you.

8. Shoe Fit Certification program
Link:Gait Guys online /download store (National Shoe Fit Certification and more !) :


9. Second metatarsal osteotomies for metatarsalgia: A robotic cadaveric study of the effect of osteotomy plane and metatarsal shortening on plantar pressure – Trask – 2013 – Journal of Orthopaedic Research – Wiley Online Library


The unbalanced athlete, motor pattern, team, joint etc…… is not efficient.

Like him or not, believing he should have lost his last fight (or not), Georges St-Pierre was/is one of the best MMA fighters of all time. He was once quoted as saying, 

“In fighting, in evolution, in life, efficiency is the key,” says St-Pierre. 

 ”It’s not the most powerful animal that survives. It’s the most efficient.

This certainly describes most of Georges fights. There were always bigger, faster, meaner, stronger opponents. However, most of his fights went the distance. Eight of his last nine fights went to a five round decision. Now, there are those who will say that he didn’t have the finishing power or submission skills to close fights in the earlier rounds, and that is debatable for sure.  However, there is no doubt that anyone’s best fighting attributes will diminish as the rounds progress and fatigue sets in.  But, perhaps this is an equalizer when someone doesn’t have one single “golden right hand”, or what have you.  Efficiency can be the great equalizer.

St-Pierre isn’t your typical fighter. He’s arguably the best mixed martial artist in the world, a 5-foot 11-inch, 190-pound destroyer. Up until his most recent fight with Johnny Hendricks, he had not lost a round in more than 3 years, that is pure efficiency ! Arguably, he is faster than other fighters, he is more fit, has a greater range of skills, has better endurance …  in a Darwinian sense, perhaps more efficient ?

Here at the Gait Guys we are always considering efficiency.  As you can see from the slide above, there are many factors that can diminish efficiency.  We strive for as much symmetry as we can because with neuromuscular symmetry efficiency can be maximized.  Keep in mind however, that total symmetry is not always possible. Most people have two different feet, often one is more varus because it sat against the mothers rounded belly in utero.  And, one tibia is often more bowed or torsioned than the other for the same reason.  So, perfect symmetry is not always possible or guaranteed. But, one can do alot to gain as much physical symmetry as possible through detailed study of your client. (Remember, just because things look symmetrical does not mean that they function symmetrically ! This game is not that easy ! But, for some of the uneducated, it may seem to be !)  When physical symmetry is regained often the sensory-motor nervous system becomes functionally more symmetrical.  And, this is a flippable phenomenon, when neuro symmetry is driven often physical symmetry will be driven in time.  

Think about the afferent input to the cortex from the peripheral receptors in the skin (Paccinian corpuscles, Merkels discs, etc); the joint mechanorecpetors (types I-IV) and muscle receptors (spindles and Golgi tendon organs). Generally speaking, they travel up the dorsal columns on the back of the spinal cord to the thalamus and then the cortex; up the dorsal spinocerebelllar tract, to the cerebellar hemispheres; the spino- reticular tract to the reticular formation, or in the case of the upper cervical spine, directly into or flocculonodular lobe of the cerebellum. This information needs to be equal and opposite from each side of the extremity (flexors and extensors) as well as the right and left sides of the body. This “Balance” or “Homeostasis” or what the Chinese called Yin and Yang is key to efficiency.

In your workouts and rehab, strive for symmetry. We like to say “Tailor your exercises to the weaker side”. This helps to create more equality rather than a larger disparity.

The Gait Guys. Making it Real…Each Day….On the Blog…

How well do your boots fit your ride?

Whether you ski, ride, nordic or tele, having the right boot fit can make the difference between a good day and a great day. It can accelerate your learning curve, prevent injuries, keep you warm and make you more comfortable. Not all feet are made the same and neither are ski boots. Good fit requires time and patience (lots of both). Here are a few tips for better fit.  

What kind of a skier/rider are you?  Recreational, competitive, racing, extreme?  How you’ll use the boot will often determine the type of boot that is appropriate for you.  In my opinion, you should get a boot that is a little above your ability (unless you are not interested in improving your skiing and/or riding), so that you will improve and “grow into” the boot.  This will ensure that you’ll continue to improve in your snowriding abilities.  Boots are very high tech these days and a subtle change in stiffness or angles can make a drastic difference in your skiing/riding.

The first thing you need to do is look at your feet.  Are they feet to the same from side to side (ie. same size and shape)?  These are the platform for the rest of your body.  What happens down there will affect everything else. Take a good look at your feet while you are standing. Are there bunions, calluses, hammertoes (toes curled under), or a Morton’s toe (2nd toe longer than your big toe)?  Do you pronate excessively while standing or walking (this will look like your arches are collapsing)? What is the relationship of the forefoot (front of your foot) to the rear foot (is the ankle sideways when viewed from behind? It should be neutral without your heel turning in (inversion) or turning out (eversion). The forefoot (front of your foot) should be flat on the ground. Does your ankle bend back as far as it should (this is called dorsiflexion). This will have an effect on the forward lean of the boot. Are you bowlegged or knock-kneed? This will cause you to ride on the outside or inside edge of your ski/ snowboard.

If you pronate excessively, have increased or decreased flexibility in the forefoot, rearfoot or big toe, have bunions or hammertoes, or are excessively bowlegged or knock kneed, proper fit and comfort while skiing will probably require a full contact orthotic or footbed. Hard deformities, such as bunions, may require liner and or boot shell modification.

Good socks are next on the list.  Wool or wool blend socks are best. The intertwining fibers of wool create air pockets, which make it both insulating and breathable. Wool absorbs sweat in its vapor state, before it liquefies, keeping you dry. It utilizes your own body heat to evaporate the moisture. This also helps to eliminate odor. No cotton socks, as they hold moisture, often creating blisters and providing a breeding ground for bacteria that cause odor; no multiple pairs, as they make feet cold. Remember, thin is in… let the liner do its job.

Have your foot measured utilizing a Brannocks device in a standing position.  Remember that your arch will flatten as you put weight on it. Remembering that the foot elongates with weight on it, will be useful for the next step.

Next you need to have the right sized ski/snowboard boot shell. This is as important for hard boots as soft boots Take the liner out of the boot and put your foot inside the shell so that your toes are just touching the front of the shell.  There should be approximately ½ – ⅝ of an inch (two crossed fingers thickness) behind the ankle to the back of the shell.  More than ¾ of an inch will cause too much heel rise once the shells are “packed out”.  There should be ¼ – ⅜ of an inch space between the feet and the side shell of the ski boot.

Now comes the liner. The liner should fit snugly.  Very snugly.  There should be no pressure spots anywhere on your foot.  Put in your foot bed or custom orthotic if available, before sizing the shell.  Remember that you’ll gain between ⅛ and ¼ of an inch of space with break-in when the liners “pack out”.

Buckle the boots loosely and flex the boot forward.  This will help to “seat the heel”.  Remember that if the you cannot flex the boot at room temperature, you will not be able to when the plastic is very cold. Now that the heel is seated, buckle the boot more firmly.  They should not be on the last buckle.

Now simulate some ski/ride movements.   If the boot is relatively comfortable, proceed to the next step otherwise repeat with different shell/liner size.

The cant of the boot (cuff alignment) needs to be adjusted next. This needs to be done by someone other than yourself (because you are standing in the boot). A plumb line dropped from the knee should pass between your second and third toe.  This ensures an even transfer of weight from edge to edge. Most boots are built with about 4 degrees of varus (lateral cant).  If you are not able to adequately align the foot, consider orthotics or having the boot shimmed. Remember that boots with higher cuffs will have more of an effect on your stance.  

Most boots provide between 12-16 degrees of forward lean.  If there is less than 12 degrees, consider a heel lift to place your body weight forward.  Remember to consider how much ankle dorsiflexion you have.

Once these adjustments are made, simulate skiing/riding movements in the shop for at least an hour.  Remember that ski/snowboard boots are made for snowriding, not walking. Now remove the boots and socks and look for “hot spots” on the feet that will show up as red marks.  These may represent areas in the boot liner or shell that need to be stretched and/or fitted better.

Well. There you have it. Now you know lots more than you knew when you began this article. As you can see, it is a very time consuming and labor intensive ordeal. Often times, people need professional help with the whole process and often require a foot bed or full arch contact orthotic. Become familiar with your own feet and then become familiar with the people or shops that do good boot fitting (ask around) and consider enlisting their help on your journey to the perfect boot.

The Gait Guys. Making it real…here….on the blog…with every post…

Gait is a Fingerprint.  

“Just because you see something you do not like, does not mean that it is wrong. “

How many times have you heard us say this ! Yes, we are getting tired of saying it, too. But, it is the honest truth.   

The above slide is one that we are using in an upcoming teaching presentation for you folks.  And this slide pretty much tells it like it is.  That being, that gait is a unique and variable fingerprint.  The slide suggests, with references, that gait is so variable, that even people with the same disease process have different presentations miles apart from one another. 

This gait analysis thing is not simple. If you are using a piece of analysis software that has you comparing your patients to normative data, be careful. You are very likely not comparing “apple to apples”.  So, do not pigeon-hole your client to normative data. Do your hands on physical examination and find out where THEIR limitations are, not what the normative data says their capacities should be.  This could be one’s first mistake in trying to help a client.  

Bottom line, no 2 people’s arms swing, leg swing, pelvic posture, hip extension etc are the same. Even side to side on the same client there may be variability due to degrees of long bone torsion or foot type (we have discusses these embryologic issues previously many times here on our blog). So, just try to improve your clients function and stability and mobility to what their body needs.

This is not a templated game. This an art form that takes years to develop. We too are learning and growing, so thanks for being on this journey with us !

Shawn and Ivo, the gait guys

Start with the basics: One of our favorite Core Exercises for the obliques.

Following up on yesterdays post, here is one of our all time favorite exercises for core stability. It focuses on the external obliques, but hits all the major players. This exercise has been adapted and modified from from Shirley Sahrmann’s book “Diagnosis and Treatment of Movement Impairment Disorders”. It is shown here excerpted from our video series, available by clicking here.

Her is a quick summary you are free to reproduce for home or clinic/ shop use (they are copyrighted) but not for resale. Please give us credit if you pass them along!

Non Tripodding Exercise

The purpose of this exercise is to improve the strength of your abdominal muscles.  You will also learn to prevent lower back (lumbar spine) motions associated with leg movement.

STARTING POSITION: Lie on your back on the floor. Bend both knees about 90 degrees with the feet flat on the floor.

Contract your abdomen, do not hold your breath or hollow. 

Lift one foot off the floor slightly and hold it there. Lift the opposite leg until your thigh is vertical. Do not push down with the opposite leg while lifting! Repeat for 5-10 repetitions with good form. Repeat with the opposite leg. Remember not to contract the muscles on the back of your thigh on the leg you have on the floor.

Perform 5 repetitions 2 times per day increasing to 3 sets of 10 repetitions.

The Gait Guys. Showing you how to get it done, each and every post!

The Lumbar Lordosis and Pelvic Stabilization Exercises

We had an inquiry regarding maintenance of the lumbar lordosis during exercise: Do you keep the spine flexed or in a “neutral” posture?

Here was our response:

“A decreased lumbar lordosis increases shear forces in the lumbar spine, as the plane of the multifidus and rototores with lumbar flexion become more parallel with the lumbar spine (see above: from McGill). This changes the angle of insertion of the muscles and they cannot stop the forward movement of the vertebrae, creating shear, which can be damaging to the discs. If they are experiencing pain during an exercise with increased flexion, that may indicate discogenic pain, poor stabilization or both.
Placing the spine in too much extension will cause the facet joints to bear too much weight (normally they are to bear approximately 20%: Kirkaldy Willis) resulting in facet irritation. If they are experiencing pain during an exercise with increased extension, that may indicate a facet issue or poor stabilization (or both).
We would emphasize that the patient needs to be in a NEUTRAL spine, not necessarily extension. Exercises should be minimized to a pain free range of motion or removed from their rehab program until they are able to perform the motion competently and in a pain free range.

Sometimes , patients need to “slow down” and though they are anxious to proceed, we must make sure they have adequate stabilization and appropriate technique.”

The Gait Guys. Giving you the facts and the info you need to make great decisions.


Some light, entertaining gait candy for you to see. This one is from May 2011; an oldie but a goodie. Enjoy!

Lets look at this Hitchcock classic “North by Northwest” and check out Cary’s form.

1st of all, what an arm swing! Think of all that energy it is sapping from the rest of his muscular system. He must be hiding something, but what? We can only see him from the waist up, so we may never actually know. Did you notice how he initially only turns to the right? Did you pick up on the flexion at the waist? How about that torso bob from side to side? Not much to his hip abductors now are there?

The only thing he has going for him is he is wearing leather soled shoes, which have been shown to have one of the lowest impact loading on the body (yes, you read that right; increased cushioning INCREASES impact forces, but that’s not what we are here to talk about). Oh yea, he actually impacts the ground at the end of the sequence. I guess if his technique was better, he would have hit even HARDER.

Next sequence, we are off to a good start, look at that forward lean to start! This is essential to good technique. He loses that form pretty quickly; we can still see that forward flexion at the waist; certainly costing him energy by not using his core.

Finally, we get a posterior view at the end, but the uneven surface makes it difficult to make an analysis.

We think Cary would certainly give Lola a run for her money. Cary, next time, engage your core and watch your step…

We Remain….The Gait Guys

The Cross Over Gait

Did you miss our teleseminar presentation on this topic last night on www.onlinece.com ?

Here is a sample of one of our slides.  The cross over gait is potentially a real problem for some. The question is always, how much cross over (running or walking) is too much for a client ? When does it need corrected ? Does it need corrected ? Leave it alone ?  We answered these hard questions in our teleseminar.  

Lucky for you www.onlineCE.com recorded it so you can take the class anytime !  (just give them a few days to process the recording). 

As you can see from just this slide here, we looked at many aspects of the cross over. But we also discussed STEP WIDTH, lateral compartment weakness and tightness as coexisting pathology, and so much more.  Stay tuned, we will be recording this program into an extended and more in depth course for you all in a video format with course notes and more and then have it for you on our Payloadz website (which you can access here for our present offerings).

In the mean time, consider looking for these “Big 6” and when you see them co-existing you might want to look for a cross over pattern in your client, it just might be there sometimes.

– weak gluteus medius

– weak TVA and obliques

– weak adductors

– weak medial quadriceps

– weak tibialis posterior

– excessive foot pronation

Shawn and Ivo, The Gait Guys

Hallux Varus: The anti-bunion. Thinking of bunion surgery ? This could be a complication if things go sour.

Hallux varus, when the big toe drifts medially, is a real problem. It is typically an acquired problem from a hallux valgus/bunion surgery gone awry.  (This post will not delve into some of the suspected culprits of this problem including Mc Bride, Scarf, Chevron or Akin osteotomy etc but that would be some of the reader’s next steps into diving deeper into this problem. Surgical procedures to the 1st ray was one of the gait guys senior orthopedic residency thesis topics, hence we now hate this topic !). 
This deformity can be rigid or flexible.  This case seen in the photo walked into our office recently.  These are not all that common and you won’t see many of them, but you do need to know they exist and where they can come from, how to cope with them and what issues you will need to understand (ie. footwear, talked about below) to assist your client. 
Hallux varus can be painful, uncomfortable and even debilitating in some cases.  Sometimes they necessitate fixation to realign the hallux bone along a more reasonable alignment with the shaft of the 1st metatarsal. 
Early correction seems critical because the linear and rotational forces at work generating the deformity can eventually lead to a further progressing deformity that can be even more problematic. When left unaddressed more drastic and radical corrective interventions seem necessary, including but not limited to, resection of the base of the proximal phalanx, fusions and tendon transfers. However, newer surgical procedures are coming along proposing things like reconstruction of the lateral stabilising components of the first metatarsophalangeal (MTP) joint. 
So here at The Gait Guys we like to ask the big, and sometimes obvious, questions.  What is toe off in walking and running gait going to look like in this hallux varus case ?  Well, one has to consider that the normal linear and rotational forces are now changed.  This means that the normal eccentric axis of the 1st MPT joint involved is going to very likely be changed. This means that the clearance of the base of the phalanx could be impaired and lead to painful binding, grinding or locking of the toe prior to reaching the adequate range of dorsiflexion for normal toe off. Additionally, the toe may act functionally unstable as the rotational forces remain unchecked leading to joint instability. Naturally, the medial foot tripod will be impaired and since the big toe acts in part like a kickstand to help support and fixate the 1st metatarsal (medial tripod), pronation forces can remain unchecked and beyond normal.  Naturally the foot will attempt to shift the tripod stability elsewhere and often this goes to the 2nd metatarsal commonly found with hammering of the digit in an attempt to help with stability through increased long flexor tone (FDL). Pain with a hallux varus can be a bigger complaint than the unsightly surgical outcome.
There is so much more to this topic. We could go on for at least another 50 pages on this topic (as our thesis reminds us) but volume is not the point of today’s task. It was to bring something new to light for our brethren here at The Gait Guys.  In the photo above, you see drift of the lesser toes, seemingly to follow the big toe. What you need to know is that this is not typical, however not impossible one could propose. This client had some other forefoot procedures done that were largely, although not exclusively, related to that lesser digit drift. Regardless, this is a client that is in some amount of foot trouble. They had good mobility of the 1st MTP joint, so full toe off was possible but because of the instability and uncontrollable rotational forces the joint was painful. A simple intervention made her life infinitely more comfortable, moving her into rigid rocker bottomed shoes.  Dansko clogs for work, and ROCS shoes for walking.  This left us with a very happy client. Not bad, all things considered.  In the mean time we will watch for deformity progression even though the patient could not be urged to have another surgery probably even if their life depended upon it. 
In summary, being a patient can be difficult. These days, more than ever it seems, one needs to do their homework and be their own advocate.  Prior to surgery several consults should have taken place, risk and rewards should have been discussed, realistic outcomes dialogued and perhaps most of all questioning whether surgery needed to be on the table in the first place. Remember, surgery is most wisely selected in cases of neurologic decline and excessively painful and further detrimental biomechanics (ie. unaddressed ACL deficiency eventually promoting secondary instability with time). If there are ways around either, they should be explored. Cosmetic correction should never be on the table, and in the case of the foot, nor should poor shoe choices that promote problems.