Podcast 33: Heart Beats, Toe walking & Crawling

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other web based Gait Guys lectures:

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

Today’s show notes:

Neuroscience Pieces:

1.Superhuman sight and hearing.


2. Kickstart device

Kickstart from Cadence Biomedical is designed to help improve the gait of people who have difficulty walking and help them regain their mobility and independence. But unlike its robotic cousins that are powered by weighty rechargeable batteries, the Kickstart is able to ditch the batteries altogether because it has no motors to power. Instead, it is purely mechanical and provides assistance by storing and releasing kinetic energy generated by a person when walking.

3. Bionic ear
Scientists have created a 3D-printed cartilage ear with an antenna that extends hearing far beyond the normal human range.
In general, there are mechanical and thermal challenges with interfacing electronic materials with biological materials,” said Michael McAlpine, an assistant professor of mechanical and aerospace engineering at Princeton and the lead researcher. “Previously, researchers have suggested some strategies to tailor the electronics so that this merger is less awkward. That typically happens between a 2D sheet of electronics and a surface of the tissue. However, our work suggests a new approach — to build and grow the biology up with the electronics synergistically and in a 3D interwoven format.”



4. Blog reader asks:
I recently came across “The solitary externally rotated foot”, as well as the Cross Over Gait, and Applied Gait Hip Mechanics videos. First of all, your material very insightful, so thank you! I am an amateur runner that exhibits external foot rotation and cross over running, which I suspect causes my hip pain (where the GMed joins the femur) over long distances. Curiously, this pain completely disappears when running up hill. Is this an anomaly, or does the slope correct my gait somehow?

5. FACEBOOK readers asks:

  • HI: Can you tell us what role the gluteus medius plays in foot pronation. What if they are weak or tight? And how about the QL, too? Would a foot supinator have weakened QLs (they don’t get to work much) and a foot overpronator have over-worked/loaded QLs (controlling spin)? And hey, if I toss in functional scoliosis in the lumbar region to this mix, well, what a tight mess I have, eh? Any insights on how to become unscrewed?

6. Karis

  • Hi there, I’m sure you get 100,000 messages so thank you for your time for reading this! Today I had a revelation that I have external tibial torsion. After much googling about my knees turning in quite a lot when my feet are straight I finally found it! Then I found your blog on Tumblr and read all about it and watched the videos. I just wondered if you had any advice on running, I am keen to start running but I didn’t know whether to run with my feet sticking out as my natural position or anything else I should be doing? I also wondered if it can be corrected marginally by doing any strength exercises? Thank you for your help in advance! Karis


Some of the signs of overtraining may include an unexplained decrease in performance, changes in mood state, excessive fatigue, the need for additional sleep, frequent infections, continued muscle soreness and loss of training/competitive drive.

We have included an article that puts it into simple light for the athlete:

J Nov Physiother. 2013 Feb 16;3(125). pii: 11717.
8. Toe walking in children
In most cases no etiology of toe walking is found. The medical literature considers it abnormal if it persists after 3 years of age. Idiopathic Toe Walking (ITW) is considered a diagnosis of exclusion and is employed only when all other possibilities have been eliminated with a meticulous clinical examination and various investigations. If any etiology is found, the treatment should be first non operative
The differential diagnosis in children who walk on their toes includes mild spastic diplegia, congenital short achilles,  and idiopathic toe walking (ITW).  A reduced ankle range of motion is common……one just needs to find the source of the reduction…….meaning funcitonal,  ablative (structural). Reported treatments have included serial casting, Botulinum toxin type A or surgery to improve the ankle range of motion.  Is there an immediate impact of footwear, footwear with orthotics and whole body vibration on ITW to determine if any one intervention improves heel contact and spatial-temporal gait measures.

BMC Musculoskelet Disord. 2011 Mar 21;12:61. doi: 10.1186/1471-2474-12-61.

9. Idiopathic toe-walking in children, adolescents and young adults: a matter of local or generalised stiffness?

Engelbert R


10. J Foot Ankle Res. 2010 Aug 16;3:16. doi: 10.1186/1757-1146-3-16.

Idiopathic toe walking and sensory processing dysfunction.

11. Crawling May Be Unnecessary for Normal Child Development?


Hmmm. We are fully internally rotating this gentleman’s lower leg (and thus hip) on each side. What can you tell us?

Look at the upper picture. Does the knee go past midline? NO! So we have limnited internal rotation of the hip. What are the possible causes?

  • femoral retro torsion
  • tight posterior capsule of hip
  • OA of hip
  • tight gluteal group (max or posterior fibers of medius)
  • labral derangement

Now line up the tibial tuberosity and the foot. What do you see? The foot is externally rotated with respect to the leg. What are the possible causes?

  • external tibial torsion
  • subtalar valgus
  • fracture/derangement causing this position

Now look at the bottom picture. Awesome forearm and nice choice of watch. Good thing we didn’t wear Mickey Mouse!

Look at upper leg. Hmm. Same story as the right side.

Look at the lower leg and line up the tibial tuberosity and the foot. What do you see? The foot is internally rotated with respect to the leg. What are the possible causes?

  • internal tibial torsion
  • subtalar varum
  • fracture/derangement causing this position

So this individual will have very different lower leg mechanics on the right side compared to the left (external torsion right, internal left). We refere to this as “windswept” biomechanics, as it looks like the wind came in from the right and “swept” the feet together to the left.

What will this look like? Most likely increased pronation on the right and supination on the left. What may we see?

  • calcaneal (rearfoot) valgus on right
  • calcaneal (rearfoot) varum on the left
  • bilateral knee fall to midline
  • knee fall to midline on right occurring smoother than on left
     (the patient has an uncompensated forefoot varus bilaterally; he is already partially pronated on the right, so it may appear to be less abrupt)
  • toeing off in supination more pronounced on the left (due to the internal torsion and forefoot varus)

The Gait Guys. Increasing your foot and gait IQ with each and every post.

Take a  look at these dogs

Take a good look at these shoes. Notice the wear at the heel counter. Did you notice the varus cant  of the rear foot. Good! Did you carefully inspect where the upper was attached to the midsole? Now did you notice that upper is canted in varus as well? This person DID NOT have a rear (or forefoot) varus.

Hmmm. Maybe the varus canting of the upper caused the wear on the outsole? We doubt it; most likely it was the other way around.

What sort of  symptoms so you think they had?

Do you think medial or lateral knee pain?

 Could be either.

  • Lateral; knee pain from stretch on the lateral side of the knee at the lateral collateral ligament or
  • medial from compression of the medial condle of the femur and medial tiibial plateau.

Anything else?

How about pain on the outside of the hip? Canting the foot laterally has a tendency to externally rotate the lower leg and thigh. This may cause shortening of the gluteals (max and post fibers of the min); difficulty accessing the gluteus minimus (its a medial rotator), shortening of the deep 6 external rotators, difficulty accessing the vastus medialis (external rotator when foot is on the ground), and the list goes on.

What’s the fix?

New shoes. Pay attention when you buy shoes. Put them up on a counter at eye level and inspet them closely. We can’t tell you how many defects we see on a daily basis; too many to count. One time at a shop, we needed to go through 10 pair before we had a good right and left.

The Gait Guys. Bald. Good looking. Smart. Increasing your “Shoe IQ” every day.

 Want to  know more? Take our National Shoe Fit Certification Program. It’s the only one of its type and the only one certified by the International Footwear and Gait Education Council. Drop us an email at: thegaitguys@gmail.com for more details or go to our payloadz store  (click here) and download it today.

All material copyright 2013 The Gait Guys/ The Homunculus Group.

And what do we see here?


Let’s test your Observation skills:

Another “Gait Quickie”. Please watch the video (front and side views) and come back to see if you saw what we did:

Front view:

·      Cross over gait

o   Should be no cross over

·      Decreased progression angle R > L

o   Progression angles should be relatively symmetrical

·      Increase valgus angle at knees

o   Q angle less than 12 degrees

·      Arm swing increased on L

o   Should be symmetrical

·      Pelvic shift L > R

o   Should be little pelvic shift to either side


Side view:

·      Foot strike in front of body

o   Should be  under body

·      Lack of or incomplete hip extension

o   Hip should extend at least to match ankle dorsiflexion. We find 15 degrees is requisite to be asymptomatic

·      Forward flexion at waist

o   Forward lean should be at ankles

The Gait  Guys. We are watching your gait. Are you?


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

“Georges St-Pierre, MMA Limb Power & Spinal Stiffness” … Gait Guys style.

Here at ‘The Gait Guys’ we have been going at this teaching, writing and filming process for many years now. On our blog we have written over 900 articles, our YouTube Channel and Facebook page continue to grow  and our podcasts continue to be heard presently in 64 countries.  We have a long way to go to get our message heard but we trust that our message is clean and clear and based on science and fact. Today we share with you a video of one of our personal professors from our undergraduate studies in human kinetics back in Canada in the late 1980’s, the world renowned Dr. Stuart McGill. In this video he speaks some of these clear honest facts about the spine, movement, joint loading and the sport of MMA (Mixed Martial Arts).  Watch the video, but be sure to read on here, where we bring things full circle for our readers.

We have been on a long academic quest when it comes to learning about different types of movement and we are willing to go to great lengths to humble ourselves to further this mission. Many of our long time readers are aware by now that at the end of 2012 Dr. Allen completed 3 years of private study of smooth and Latin dance to better understand the intricacies of core strength, foot work and complex limb coordination amongst other things. If it was good enough for Bruce Lee (1958 Hong Kong Cha Cha Champion) it is good enough for us ! Just like Tim Ferris, one of the modern day bio and brain hackers, who also took up the Tango to put to the test some facts about brain learning, we too are in it to learn and take things to the highest level possible.  You can read more about some of Dr. Allen’s neurologic and orthopedic revelations over the 3 years of dance study here in these articles he wrote with Dr. Waerlop.

Many of you by now know that I have moved on from dance (for now) into a different kind of study in human movement. I have now committed my brain and body to learning Brazilian Jiu-Jitsu under the instruction of World renowned World Champion Professor Carlos Lemos Jr. and Champion Professor Ryo Ominami. You can read about them here, Gracie Barra Downers Grove

There are many similarities between dance and jiu-jitsu (believe it, it is true) and we have completed a comparative article which we will post on The Gait Guys blog in the coming days to validate these thoughts on the human frame in both sports.  However, this is not the point of this brief blog article today, our point was to share the teachings of one of our mentors Dr. McGill.  In this video, showing the research of human movements of Georges St-Pierre and David Loiseau, Dr. McGill discusses the basic tenet that the hips and shoulders are used for power production and that the spine and core are used for creating stiffness and stability for the ultimate power transmission through the limb.  He makes it clear that if power is generated from the spine, it will suffer.
McGill implies that martial artists find themselves near the top of the heap when it comes to power, strength and speed with an ability to contract muscles with great velocity but also the ability to relax the muscles with a terrific rate of speed. It is this ability to effectively and timely contract and relax that gives a martial artist the advantage.
However, these advantages can only be realized with a special ability to create spinal stiffness effectively, efficiently and with speed and coordination. These are huge advantages when in combat. We all hear about the importance of the core but these are the tenants that are key when referring to the core. And as McGill states, in martial artists who kick and punch, there must be an ability to create an initial pulse of energy, premised off of a stiff and stable spine. This is then followed by a relaxation of some of the limb muscles to ensure maximal velocity (a kinetic chain whip effect, like snapping/flicking a towel) and then followed by a sudden and timely re-stiffening of the spine, core and limb muscles to ensure that maximal force is transmitted to the opponent.
The spine and core must present sufficient amounts of recruited stiffness, yet mobility where necessary, to enable the power and velocity of the movements of the shoulders (punching) and hips (kicking) which are the two main portals of limb movement off of the spine/core.  These principles holds true in gait as well. For example, in human gait the psoas is not a hip flexor initiator when it comes to leg swing, it is a hip flexor perpetuator. The initial hip flexion in human gait comes from derotating the obliqued pelvis, via abdominal contraction, on a stiff and stable spine.  Once the pelvis rotation is initiated, the femur can further pendulum forward (via contraction of the psoas and other muscles) on the accelerated pelvis in the hip joint proper creating an energy efficient movement (again, the towel flick/whip effect). So, this premise holds true in gait, in an effective martial arts kick or even in a soccer kick. This is a solid principle of effective and efficient human locomotion. This principle also holds true for a punch or throwing an object, the stable torso/spine provides a stable anchor upon which to accelerate the arm in order to create a high velocity limb movement with power.

Watch the attached video of Georges St-Pierre, David Loiseau and Dr. Stuart McGill. These are foundational principles of movement in many sports and the martial artists seem to have it down pretty darn well.  These are the things we study and write about here at The Gait Guys. We are more than just gait.
Dr. Shawn Allen (white belt Brazilian Jiu-Jitsu)
Dr. Ivo Waerlop (black belt in neurology)
visit our daily blog:   www.thegaitguys.tumblr.com or our other social media sites, YouTube Channel, Facebook, Twitter etc
copyright 2013 The Gait Guys/The Homunculus Group. All rights reserved. Video remains property of said owner.

What can we learn from a trip to the museum and ancient pachyderms?

Lessons from the Denver Museum of Science and the “Mammoths and Mastodons” exhibit.

Leave it to gait nerds to notice stuff like this. These are the things that keep us up at night.

Look carefully at the last 2 pictures, especially the femurs. Besides their grandious size, what do you see. Femoral anterversion! The angle of the femur head with the shaft of the femur is quite large. We remember from our discussion of anteversion previously (see here); that femoral anteversion allows a greater amount of internal rotation of the head of the femur in the acetabulum (ie the ball in the socket).

Now look at the top picture. Besides a cross over gait that Dr Allen was quick to point out. What do you see?  Ok…tremendous glutes : ). What else? Look at the second picture for a hint. You got it! Internal rotation of the legs.

Think about how pachyderms are put together compared to say, reptiles, specifically lizards. The legs are UNDER the body in the former and STICK OUT from the body in the latter. Watch them walk. The latter swing their tails and the former have the legs under their center of mass.

Extrapolate this to human gait (We know, it’s a stretch, but you have a great imagination). Some people have their weight under their body (ie, they have sufficient internal rotation of the hips to allow this; many of these folks have more anteverision than retroversion. also remember that we are speaking versions, NOT torsions here). Think about retroverted folks. Wider stance, wider gait, just like reptiles.

Ok, maybe this was a stretch, but it was cool, no?

The Gait Guys. Comparing pachyderms to humans….reallly.

all material copyright 2013 The Gait Guys/The Homunculus Group. All rights reserved.

Human Gait Changes following mastectomy. Taking Angelina Jolie’s news and putting it into gait context.

The Gait Guys are on the case looking at the effects of gait changes following mastectomy just a day after the news of Angelina Jolie’s double mastectomy.

Research has confirmed that following a mastectomy there are limitations in the efficiency of the upper limb and even changes in the posture of the torso. (1,2,3)

Following mastectomy, whether unilateral or bilateral, restorative measures are necessary. From a biomechanical perspective, obviously depending on breast size, removing a considerable mass of tissue is going to change the symmetry of the torso particularly if we are dealing with a unilateral mastectomy.  Not only is it going to change symmetry from a static postural perspective but it will change dynamic postural control, mobility and stability as well as dynamic spinal kinematics.  The literature has even shown that post-mastectomy clients display changes in spatiotemporal gait parameter such as step length and gait velocity.

Breast tissue moves. It oscillates a various cycles depending on speed of walking or running.  There is a rhythmic cycle that eventually sets up during walking and running and the cycle is intimately and ultimately tied to arm swing.  Thus, it would make sense that removing a sizable mass of tissue, particularly when done unilaterally, will change the tissue and joint rhythmicity. And if you have been here with The Gait Guys for more than a year you will know that impairing an arm swing will show altered biomechanics in the opposite lower limb (and furthermore, if you alter one lower limb, you begin a process of altering the biomechanical function and rhythmicity of the opposite leg as well.)  Here are 2 links for more on these topics, Arm Swing: Part 1 and Arm Swing: Part 2, When Phase is Lost. Plus here from our blog search archives, everything we have talked about on Arm Swing.

Arm swing impairment is a real issue and it is one that is typically far overlooked and misrepresented. We are currently working on several other blog posts for near future release including walking with a handbag/briefcase, walking with a shoulder bag, walking and running with an ipod or water bottle in one hand and even spinal symmetry changes from scoliosis that can either consciously or unconsciously alter arm swing and thus global body kinematics.  (We have also noted changes in opposite leg function secondary to a frozen shoulder (adhesive capsulitis) and we have that blog article in the works as well.)  The bottom line is that because of the neurologically embedded crossed extensor reflex and cross crawl response that permeates all human locomotion, anything that changes one of the limbs, whether it be a direct limb issue or something to do with the stabilization of the limb (as in this case the breast/chest wall), can and very likely will impair and change locomotion and motor pattern choices and programming.

Obviously the degree to which intervention is taken depends on the amount and location of breast tissue removed and intervention will be determined by physical placement of the prosthesis (whether it be external or internal) as well as the prosthesis weight, shape and possibly several other independent factors such as comparative support to the chest wall in comparison to the opposite breast. (In another future blog post we will address other methods of intervention such as latissimus dorsi relocation to reform the breast mass. This deserves a blog article all on its own because taking away a major shoulder, scapular and spinal stabilizer and prime mover has never made sense to us clinically or biomechanically.)

In Hojan’s study (below) they found significant differences in the gait parameters in the younger age groups with and without breast prosthesis however there appeared to be no significant differences in the women of the older study group.  However, it appeared that their study did not take into account all of the intimate issues we talk about in gait here on The Gait Guys blog. None the less, in the younger and likely more active study group, the use of a breast prosthesis brought the gait parameters closer to the healthy control group, as we suspected. 

Bottom line, every external and internal parameter that changes affects the human organism and thus affects their gait.

Again, here are those links to our other blog writings on arm swing that are paramount to understanding what we are discussing here today.

Arm Swing Part 1: The Basics    http://thegaitguys.tumblr.com/post/13869907052/arm-swing-in-gait-and-running-part-1-there-is

Arm Swing Part 2: When Phase is Lost    http://thegaitguys.tumblr.com/post/13920283712/arm-swing-part-2-when-phase-is-lost

From our blog search   http://thegaitguys.tumblr.com/search/arm+swing

Shawn and Ivo, The Gait Guys

1.Blomqvist L, Stark B, Engler N, et al. Evaluation of arm and shoulder mobility and strength after modified radical mastectomy and radiother- apy. Acta Oncol. 2004;43(3):280Y283.

2. Rostkowska E, Bak M, Samborski W. Body posture in women after mastectomy and its changes as a result of rehabilitation. Adv Med Sci. 2006;51:287Y297.

3. Crosbie J, Kilbreath SL, Dylke E, et al. Effects of mastectomy on shoulder and spinal kinematics during bilateral upper-limb movement. Phys Ther. 2010;90(5):679Y692.

4. Hojan K, Manikowska F, Molinska-Glura M, Chen PJ, Jozwiak M. Cancer Nurs. 2013 Apr 29. [Epub ahead of print] The Impact of an External Breast Prosthesis on the Gait Parameters of Women After Mastectomy.


Join us tonite 8PM EST (7PM CST, 6PM MST) for a case study in gait analysis on chirocredit.com or onlinece.com. Tonite’s case involves a common neurological lesion that effects gait. In addition to a history and gait analysis, remediation of this commonly seen problem is discussed.

Hope t see you there

Ivo and Shawn

Being a gait geek offers you a unique perspective in many situations.

Perhaps you have been with us for some time now and would like to check your gait acumen. If you are new, or these terms are foreign to you; search here on our blog through hundreds of posts to become more comfortable with some of the vocabulary.

Watch this video a few times (we slowed it down for you) and write down what you see.

Did you see all of these in this brief video?

  • bilateral loss of hip extension
  • bilateral loss of ankle rocker
  • less ankle rocker on right
  • bilateral increased progression angle  
  • dip in right pelvis at right heel strike
  • arm swing increased on R

The Gait Guys. Increasing your gait competency each and every day.

special thanks to NL for allowing us to use this video footage.

Listening to music in the first 1.5 km of a run alters pacing strategies and improves performance.

How do  you feel before a race? Excited ? Adrenaine pumping? Do you ever notice how you typically “go out” a bit too fast for the first mile or two because of this ? Do you feel that it takes that first mile to find your comfortable running pace ?
How do you feel otherwise during  your training runs during the first mile or two ? Some folks feel a bit sluggish and it takes a mile to get into the rhythm and “get the bugs out”, eventually loosening up and getting the heart rate at your comfortable running rate.  For many, it takes time to get “the machine” up to cruising speed, up to cruising temperature (especially if we are dealing with some environmental temperature extremes), and to get our head “in the game” or in that meditative zone we all love so much. 
In this study the authors looked at “the effects of listening to music on attentional focus, rating of perceived exertion, pacing strategy and performance during a simulated 5-km running race”. What they found was that through the use of music they were able to create an affect on the runner’s outcome. More specifically, they discovered that listening to music at the beginning of a run may draw the person’s attentional focus away from internal sensations of fatigue and transfer their focus elsewhere thus affording a faster pace.
We have talked about the use of music in previous blog posts here on The Gait Guys regarding its function in assisting speed work and helping to set a tempo via beats per minute of the music. Interestingly in this study, because of the distracting factor of the music, the rate of perceived exertion of the runner increased linearly throughout the run hinting that the change in velocity may be to maintain the same rate of rate of perceived exertion increase.
Possible take away point?:  Well, is it possible that using music on your runs may distract you from the uncomfortable internal environment brought about by running (ie. pushing through fatigue, pain or lactate for example) that might otherwise dictate a slower pace because of perceived exertion ?  This article seems to suggest this possibility.  So, you might run faster because you have reduced your perceived effort via distraction.
Shawn and Ivo
Int J Sports Med. 2012 Oct;33(10):813-8. Epub 2012 May 16.

Listening to music in the first, but not the last, 1.5 km of a 5-km running trial alters pacing strategy and improves performance.

Lima-Silva AE, Silva-Cavalcante MD, Pires FO, Bertuzzi R, Oliveira RS, Bishop D. Sports Science Research Group, Faculty of Nutrition, Federal University of Alagoas, Maceio, Brazil. adrianosilva@usp.br


We examined the effects of listening to music on attentional focus, rating of perceived exertion (RPE), pacing strategy and performance during a simulated 5-km running race. 15 participants performed 2 controlled trials to establish their best baseline time, followed by 2 counterbalanced experimental trials during which they listened to music during the first (M start) or the last (M finish) 1.5 km. The mean running velocity during the first 1.5 km was significantly higher in M start than in the fastest control condition (p<0.05), but there was no difference in velocity between conditions during the last 1.5 km (p>0.05). The faster first 1.5 m in M start was accompanied by a reduction in associative thoughts compared with the fastest control condition. There were no significant differences in RPE between conditions (p>0.05). These results suggest that listening to music at the beginning of a trial may draw the attentional focus away from internal sensations of fatigue to thoughts about the external environment. However, along with the reduction in associative thoughts and the increase in running velocity while listening to music, the RPE increased linearly and similarly under all conditions, suggesting that the change in velocity throughout the race may be to maintain the same rate of RPE increase.

© Georg Thieme Verlag KG Stuttgart · New York.