Unique adaptations to arm swing challenges: the one armed runner.  Welcome to Luke Ericson, an amazing athlete and man.

Written By Dr. Shawn Allen

Human gait is cyclical. For the most part, when one limb is engaged on the ground (stance phase), the other is in swing phase. Before I continue, you should recall that there is a brief double limb support phase in walking gait, that which is absent in running gait. Also, I wish to remind you of our time hammered principle that when the foot is on the ground the glutes are heavily in charge, and when the foot is in the air, the abdominals are heavily in charge.  

For one to move cleanly and efficiently one would assume that the best way to do that would be to ensure that the lower 2 limbs are capable of doing the exact same things, with the same timing, same skill, same endurance and same strength. This goes for the upper 2 limbs as well, and then of course the synchronizing of the 4 in a cohesive effort. For this clean seamless motor function to occur, one must assume that there would be no injuries that had left a remnant mark on one limb thus encouraging a necessary compensation pattern in that limb (and one that would then have to be negotiated with the opposite limb as well as the contralateral upper or lower limb).  

Removing a considerable mass of tissue anywhere in the body is going to change the symmetry of the body and require compensations. One can clearly see the effects of this on this athletes body in the video above. He even eludes to the fact that he has a scoliosis, no surprise there.  There is such an unequal mass distribution that there is little way the spine had any chance to remain straight.  Not only is this going to change symmetry from a static postural perspective (bulk, weight, fascial plane changes, strength etc) but it will change dynamic postural control, mobility and stability as well as dynamic spinal kinematics.  I have talked about this previously in a blog piece I wrote on post-mastectomy clients display changes in spatiotemporal gait parameter such as step length and gait velocity.

-mastectomy post: http://tmblr.co/ZrRYjx1XB8RhO

If you have been 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.) You can search the blog for “arm swing part 1 and part 2″ for those dialogues.

Arm swing impairment is a real issue and it is one that is typically far overlooked and misrepresented. The intrinsic effects of altering the body through subtraction of tissue are not all that dissimilar to extrinsic changes into the system from things like  walking with a handbag/briefcase, walking with a shoulder bag, walking and running with an ipod or water bottle in one hand. And do not forget other intrinsic problems that affect spinal symmetry, for example consider the changes on the system from scoliosis as in this case.  It can cycle back on its own feedback loop into the system, either consciously or unconsciously altering arm swing and thus global body kinematics.  

There is a reason that in my practice I often assess and treat contralateral upper and lower limbs as well as to address remnants from old injuries whether they are symptomatic or not. It all comes together for the organism as a concerted effort in optimal locomotion.

Here on TGG, and in dialogues with Ivo on our podcast, I have long talked about phasic and anti-phasic motions of the arms and shoulder-pelvic blocks during gait and locomotion/sport activity.  I have written several times about the effects of spine pain and how spine pain clients reduce the anti-phasic rotational (axial) nature of the shoulder girdle and pelvic girdle. In the video above, you can see anything but anti-phasic gait, to be clear, this is a classic representation of a phasic gait. The shoulder block and the pelvic block show little if any counter rotation, they are linked together which is not normal gait. Furthermore, if you look carefully, the timing of the right arm swing is variable and cyclically changing in its timing with the left leg. Look carefully, you will see the cyclical success and failure at the beginning of the video.  This is pathologic gait, he must be constantly fighting frontal plane sway because there is no axial anti-phasic motion. He is also constantly fighting the unidirectional rotation that the absence of an entire limb and limb girdle is presenting, you can see him struggle with this if you have looked at enough gait samplings. There is essentially frozen torso movements.  Want to see more of our work on arm swing ? search the gait guys blog.

There is so much more here to discuss, so I will likely return to this video another time to delve into those other things on my mind. Luke is an amazing athlete, he gets much respect from me.

I hope this dialogue helps you to get a deeper grip on gait and gait problems. I have written many articles on the topics of arm swing, phasic and anti-phasic gait, central pattern generators. The are all archived here on the blog. I try to write a new original thought-process article each week for the blog amongst the other “aggregator” type stuff we share from other folks social media. My weekly article serves to go deeper into things, sometimes they are well referenced and in this case, I am basing today’s discussion on the referenced work in the other pieces I have written on arm swing, phasic and anti-phasic gait, central pattern generators etc. So please do your readings there before we begin debate or dialogue, which i always welcome !

Dr. Shawn Allen

Cross Fit: Gray Cooks thoughts

Always a good read, he is always on the mark.
Gray Cook talks about CrossFit, injury rates, and protecting both elite and amateur level CrossFit athletes.
We couldn’t agree more about the fact that CrossFit often prioritizes reps and time which can lead to fatigue and compensation in lifters, often corrupting and even neglecting technique. (yes, not everyone and not ever cross fit gym, but enough that its worthy of dialogue).

Podcast 74: Cross Fit: More on Squatting and Hip Torsions, Part 2

Lots of great hip, squatting and biomechanics in this weeks show !

*Show sponsor: www.newbalancechicago.com

A. Link to our server: 


Direct Download: 


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:

Diving deeper into crossfit’s squatting, lunges, leg press.

 Walking in sync makes enemies seem less scary


The Next Big Thing In Sports Data: Predicting (And Avoiding) Injuries


“LER editor’s pick: Hip internal and external rotation are associated with shoulder mechanics in collegiate baseball pitchers. http://ow.ly/zULpO

Michael August 27 at 7:49pm I’m curious to hear some thoughts on this, too. I listened to the podcast and read the blog post by the Gait Guys. I’ve coached CrossFit since 2009 and have owned my own affiliate for the last three years and follow Starrett closely. The cue “knees out” originated in powerlifting and the purpose is to keep people from ending up compensating with a valgus knee position during a squat, which is the most common compensation. Also, CrossFit did a special “Offline Episode” with Starrett, Kilgore, Russel Berger (he represented CrossFit) and two other coaches in which the sole topic was the “knees out” cue. It’s very illuminating for this topic. One interesting thing is that CrossFit does not tell people who go through the level 1 to tell others as a law, knees out. It’s merely a cue to fix a common compensation.

Podcast 73: Cross Fit and Squatting. Knees out ?

Podcast 73: Femoral and Tibial Torsions and Squatting: Know your Squatting Truths and Myths

*Show sponsor: www.newbalancechicago.com

Lems Shoes.  www.lemsshoes.comMention GAIT15 at check out for a 15% discount through August 31st, 2014.

A. Link to our server: http://traffic.libsyn.com/thegaitguys/pod_74f.mp3

Direct Download: 

http://thegaitguys.libsyn.com/podcast-73-cross-fit-squatting-knees-b. out

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. Bioengineers create functional 3D brain-like tissue   http://www.nih.gov/news/health/aug2014/nibib-11.htm

2.  A Novel Shear Reduction Insole Effect on the Thermal Response to Walking Stress, Balance, and Gait
3.  Hi Shawn and Ivo, There is a lively debate in the Crossfit community about “knees out” during squatting. I have attached a blog post. It might be a good blog post or podcast segment. 
4. Shoe Finder ?
5.  Michael wrote: “I know this is too broad a topic for facebook, but I was wondering what your general recommendation would be for someone with flat feet and exaggerated, constant over-pronation. I’ve tried strengthening my calves and ankles, but have seen no noticeable reduction in the automatic “rolling in” of my feet whenever walking or standing. I can consciously correct the over-pronation, of course, but as soon as I stop tensing my arch muscle, everything flops back down.”

How do you measure tibial torsion anyway?

With all the talk on the Crossfit blog about the knees out debate, we though we would shed some light on measuring torsions, beginning with tibial torsion, since this does not seem to have been taken account of in the discussion and we feel it is germane. 

Yo may have seen some of our other posts in tibial torsion here or here; this post will serve to help you measure it. 

Looking at the top left picture: we can see that the axis of the tibial plateau and the transmalleolar axis (an imaginary line drawn through the medial and lateral malleolus) are parallel at birth (net angle zero) and progress to 22 degrees at skeletal maturity, resulting from the outward rotation of the tibia of about 1-1.5 degrees per year. This results in a normal external tibial version of about 17-18 degrees (you subtract 5 degrees for the talar neck angle, talked about in the link above). Note that this is the normal or ideal angle we would expect (hope?) to see. Go 2 standard deviations in either direction and we have external and internal tibial torsions.

You can go about taking this measurement in may ways; we will outline 2 of them. 

  1. In the upper left picture, we see an individual who has their knee flexed to 90 degrees over the side of a table while seated. This represents the tibial plateau angle. You the use a protractor to measure the angle between the tibial plateau and an imaginary line drawn through the medial and lateral malleoli. This is the transmalleolar angle. You then subtract 5 degrees from this number (remember the talar neck angle?) to get the angle of tibial version (or torsion).
  2. In the lower left and right pictures, we have the patient supine with the knees pointed upward and tibial plateau flat on the table. Then, working from inferiorly, use a goniometer to measure the angle of the transmalleolar axis. Again, we subtract 5 degrees for the talar neck.

We would encourage you to read up on torsions. This post, which we wrote over a year ago, is probably one of the most important ones on tibial torsions. 

Torsions. Important stuff, especially when you are talking about the axis of the knees in activities like a squat. Remember, the knee is a hinge between 2 multiaxial joints (hip and ankle) and will often take the brunt of the (patho)mechanics, as it has fewer degrees of freedom of movement. If you have external tibial torsion and you push your knees (angle your feet) out further, you are moving the knees outside the saggital plane. You have better have a very competent medial tripod! If you have internal tibial torsion, angling the feet out may be a good idea. Know your (or your patients/clients/athletes) anatomy!

The Gait Guys. Bald, Good Looking and Twisted. Here to help you navigate your way through better biomechanics.