Holy Late Cretaceous Therapods. Those Veliciraptors were twisted!

The dinosaur made famous by Jurassic Park (We never understood why they put this dinosaur in the movie, the Jurassic period was many millions of years earlier, but that’s another story).

Dr Ivo was able to take some pictures of a rare, preserved skeleton from Mongolia at the dinosaur museum in Fruita, CO, while visiting with his family.

These bad boys (and girls) were fast predators, and one of the things that made them that way, was the fact that they were built for speed!

Take a look at theses hips! Note the extreme retro torsioned angle of the femur heads. We remember that femoral retro torsion limits internal rotation of the hips (OK, so you don’t remember? click here for a review).

Now lets think about this. Externally rotate your thigh and lower leg. What do you notice? Hopefully you notice it puts your foot in more supination. This makes it into a more rigid lever, better for pushing off and better for sprinting!

Have you ever seen a sprinter? do they run on their toes? Is their foot more supinated? Ever see a velociraptor run? Check out this sequence from the “Dinosaur Planet” series. Remember, only their toes are on the ground and the thing that looks like a backwards knee is actually their ankle. 

Since their legs are so close to the body, there is little need for internal rotation, so why not maximize the effect and assist in supination?

Wow! Are you finally convinced that torsions are cool? After all, they appear to have been around for at least the last 75 million years and probably longer. 

The Gait Guys. Quarternary Geeks of the Cenozoic Era. Yes, we study dinosaur gait too…

Photo: Where is your knee joint hinge point ?  Say that 4 times fast.

Here is a photo of 4 elite runners. We suspect it is an 800m race  because #100 is Ahmed Bile who is the son of Olympian and world champion Abdi Bile.

In this photo you can see that Ahmed #100 has a significantly large foot progression angle (large foot turn out) and this likely represents external tibial torsion or femoral antetorsion while #454 has a neutral foot turn out as does #232.  #46 has a modest foot progression angle. Grossly, #46 also has the patella right over the foot and so tibial torsion is not likely. Now, move up to observe their knee progression. All of them have a forward (sagittally) oriented knee progression. How can that be? Well, it is simple if you know your torsional issues. After all, the knee is a hinge and if you are running forward your knee pretty much should hinge forward as well.  Now, there is much room for conversation here and debate but we are just trying to make and observation and a point. To a large extent the knee rules the roost in the lower limb in terms of sagittal progression because it is the joint with the least number of tolerances. The knee only hinges in flexion and extension where as the hip and ankle/foot have frontal and axial planes they can notably tap into when the sagittal is challenged.  Again, look at #100 and our point is made.

Look at the 2 fellas in the middle (454 and 232). they have a internally (medially) postured knee/thigh yet their foot progression angle is mostly neutral and the knees are hinging forward.  Does #454 have internal tibial torsion? It could be (hint, look at his right trailing leg, specifically the patella and foot postures) but the left limb looks cleaner although adducted suggesting he might like the cross-over gait or it is more external tibial torsioned. Where as the 2 outer fellas, 100 and 46, are more neutrally oriented knees/thighs (one could make the case that #100 has a more externally oriented femur) yet increased progression foot progression angle in an environment of a forward hinging knee.

So what gives ? Torsions. Yes, we are soapboxing on torsions again. Torsions in the tibia, torsions in the femur. Versions are normal expressed angles, tibial torsions are abnormal.

Now, as life would have it, look over the right shoulder of #100. See the fella in the red headband? Ya, that guy losing.  He has the cleanest lines of the bunch. How is that for cruel irony ?  Sometimes it ain’t what you got, it is what you do with what you got.  Unless of course he is actually wincing in pain and trailing behind because he got spiked by #100 and that hideously frontal plane splayed foot !

Lastly, this wouldn’t be an official Gait Guys post if we did not preach to remember that “what you see is not the problem, what you see in a gait analysis is the person’s compensatory strategy around their deficits”. And here we see deficits. Our observations today are merely just that, observations. Now someone has to get them on a table and examine them and confirm our observations, prove them wrong and/or discover the joint, muscular and motor pattern deficits that created these observations.  Or, someone has to confirm that all parts are working and that they were at the end of the line when the straight long bones were first handed out.  

Today’s Lesson:  Get in line, and get in line early. (just kidding of course)

The Gait Guys.  Calling it they way we see it, but reserving the right to plead the 5th or change our minds after an examination.  We would suggest to everyone, when it counts and when your reputation is on the line, plead the 5th, until you have completed your hands on clinical examination.  "Seeing may be believing" but that still doesn’t always make it so.

Want to learn more about these kinds of things, foot beds, foot types, shoe anatomy and shoe function, proper shoe prescription etc ?  Our National Shoe Fit program will help you get smarter about this stuff. email us at : thegaitguys@gmail.com 

Gait Guys online /download store:http://store.payloadz.com/results/results.aspx?m=80204

*Photo courtesy of BIG EAST Conference

What kind of shoe do you put this foot in?

Look carefully at these dogs. Notice anything peculiar? Look at the forefoot to rearfoot relationship. What do you see?

Normally, we should be able to draw a line from the center of the heel and it should pass between the 2nd and 3rd metatarsal heads. If the line passes through or outside the 3rd metatarsal heads, you have a condition called metatarsus adductus. It occurs from fetal positioning in utero. In children (18 mos to 4 years) it can often be corrected by wearing the shoes on the opposite feet (yes, you read that correctly)

We usually try and distinguish whether the adductus is occurring at the tarsal/ metatrsal articulation or the transverse tarsal joint.

OK, so now what?

Think of the unique biomechanics that happen here. Adduction (along with plantar flexion and inversion) are components of supination. So, the adduction component makes for  a more rigid foot (notice the arch structure in the pedograph). We are not saying this foot does not pronate, only that it pronates less.

Total amount of pronation will be determined by several factors,

• including body weight

• available rear foot motion

• available forefoot motion

• knee angulation (ie genu valgus or varus)

• available internal rotation of the hips (how much ante or retroversion/torsion is present)

• strength of abdominals, particularly the external obliques

• tibial torsion

This individual had

·       markedly increased valgus angle (14 degrees)

·       moderate external tibial torsion

·       femoral antetorsion

this, along with their body weight, explains the rear foot pronation seen on the pedograph.

So, what type of shoe? You should pick a shoe that:

·       does not exaggerate the deformity (ie. a shoe that does not have an excessively curved last)

·       a shoe that does not work (too much) against the deformity (ie. an extremely straight lasted shoe)

·       In this case, a shoe with some motion control features (to assist in controlling some of the increased rear foot motion. This may be something as simple as a dual density midsole

·       a shoe that, upon gait analysis, works to provide the best biomechanics for the circumstances.

As you can see, when it comes to shoe fit and prescription, there are no had and fast rules. You need to examine the individual and have all the facts.

If you are a little lost, or want to know more, you should take our National Shoe Fit Program. Maybe you even should consider getting Level 1 certified by taking the International Foot and Gait Education Council exam. Need more details? Email us at: thegaitguys@gmail.com

Gait, Running or Biomechanical problems ? Today we talk of Torsions and Versions….

(excerpted from the forthcoming second edition of our book)

We’ve all heard of, and probably have used, the terms torsion or version especially in the vernacular of antetorsion or anteversion and retrotorsion and retroversion. We (including authors and researchers) often like to use these terms interchangeably. Technically speaking, we have all been wrong.

Believe it or not, there was actually a group of folks in 1979 called the Subcommittee on Torsional Deformity and Pediatric Orthopedic Society whose mission was to set people straight on the differences between torsion and version. Version is actually the normal difference in angulation of the proximal and distal portions of a long bone. Torsion is said to be present when this measurement falls outside 2 standard deviations of the normal version.

Versions are present in utero and are considered part of the developmental process. For example, the femur has approximately 30 degrees of anteversion at birth (ie the femoral condyles are rotated 30 degrees medial to the plane of the femur head). During the normal developmental process, the femur “untwists” at a rate as slow as 1-3 degrees per year to approximately a 20 degree by age 6, leading to a “normal” angle of 8-12 degrees of anteversion. Of course this can occur slower or faster or to a greater or lesser degree as well resulting in a torsion, which may or may not have symptomatic sequela later in life. Regardless, these torsions are very important transverse plane deformities from a gait biomechanists point of view in regards to resultant compensations which occur in the lower kinetic chain and more proximally.

These versions and torsions can affect any long bone, but most important to us, the femur and tibia. Of interesting note, there is a 2:1 preponderance of left sided deformities believed to be due to most babies being carried on their backs on the left side of the mother in utero, causing the left leg to overlie the right in an externally rotated and abducted position.

Now maybe you will think twice about the position of the feet of a newborn when placing them on their stomach, as this posturing will effect their development over time and potentially contribute to adult torsional deformity! How’s the sleeping position of your child? Do they consistently sleep on one side? Is their thigh drawn up and internally rotated with a compensatory external rotation of the foot relative to the tibia? Wow, and you thought as long as you fed them well and didn’t let them watch too much TV that all would be OK!

Torsions and Versions…. They are not just for breakfast anymore…

Yes, we ARE a little twisted……Ivo and Shawn