Take a good look at this gals gait. In the 1st section, she is walking on relatively level ground and in the second part, the topography changes and the balance requirements become much greater. You may remember a post we did some time ago talking about proprioception and learning to walk here.

Besides the obvious gluteus medius weakness, genu valgum and pronation, R>L, can you see how when the task becomes more complex, that the system begins to break down? Did you see the increased base (wider) of gait? did you see the decreased speed of movement? Did you see the increased ancillary arm movements?

Keep your eyes open for clues like this in your clinical exam. When the going gets rough, the nervous system often reverts to what it knows best a slows down a bit.

Why alignment of the big toe is so critical to gait, posture, stabilization motor patterns and running.

There are two ways of thinking about the arch of the foot when it comes to competent height.  One perspective is to passively jack up the arch with a device such as an orthotic, a choice that we propose should always be your last option, or better yet to access the extrinsic and intrinsic muscles of the foot (as shown in this video) to compress the legs of the foot tripod and lift the arch dynamically.  Here today we DO NOT discuss the absolute critical second strategy of lifting the arch via the extensors as you have seen in our “tripod exercise video” (link here) but we assure you that regaining extensor skill is an absolute critical skill for normal arch integrity and function.  We like to say that there are two scenarios going on to regain a normal competent arch (and that does not necessarily mean a high arch, a low arch can also be competent….. it is about function and less about form): one scenario is to hydraulically lift the arch from below and the other scenario is to utilize a crane-like effect to lift the arch from above. When you combine the two, you restore the arch function.  In those with a flat flexible incompetent foot you can often regain normal alignment and function.  But remember, you have to get to the client before the deforming forces are significant enough and have been present long enough that the normal anatomical alignments are no longer possible. For example, a hallux valgus with a large bunion (this person will never get to the abductor hallucis sufficiently) or a progressively collapsed arch that is progressively becoming rigid or semi-rigid.

Think about these concepts today as you watch your clients walk, run or exercise.  And then consider this study below on the critical importance of the abductor hallucis muscle after watching our old video of Dr. Allen’s competent foot.  

CONCLUSIONS AND CLINICAL RELEVANCE:

The abductor hallucis muscle acts as a dynamic elevator of the arch. This muscle is often overlooked, poorly understood, and most certainly rarely addressed. Understanding this muscle and its mechanics may change the way we understand and treat pes planus, posterior tibial tendon dysfunction, hallux valgus, and many other issues that lead to a challenge of the arch, effective and efficient gait. Furthermore, its dysfunction and lead to many aberrant movement and stabilization strategies more proximally into the kinetic chains.

*From the article referenced below,  “Most studies of degenerative flatfoot have focused on the posterior tibial muscle, an extrinsic muscle of the foot. However, there is evidence that the intrinsic muscles, in particular the abductor hallucis (ABH), are active during late stance and toe-off phases of gait.“

We hope that this article, and the video above, will bring your focus back to the foot and to gait for when the foot and gait are aberrant most proximal dynamic stabilization patterns of the body are merely strategic compensations.

Study RESULTS:

All eight specimens showed an origin from the posteromedial calcaneus and an insertion at the tibial sesamoid. All specimens also demonstrated a fascial sling in the hindfoot, lifting the abductor hallucis muscle to give it an inverted ‘V’ shaped configuration. Simulated contraction of the abductor hallucis muscle caused flexion and supination of the first metatarsal, inversion of the calcaneus, and external rotation of the tibia, consistent with elevation of the arch.

http://www.ncbi.nlm.nih.gov/pubmed/17559771

Foot Ankle Int. 2007 May;28(5):617-20.

Influence of the abductor hallucis muscle on the medial arch of the foot: a kinematic and anatomical cadaver study.

Wong YS. Island Sports Medicine & Surgery, Island Orthopaedic Group, #02-16 Gleneagles Medical Centre, 6 Napier Road, Singapore, 258499, Singapore. 

Circumducting gait.

This is a great video. This is a video we found on the internet. There is another one showing her with a much more pathologic steppage gait, we may bring this one to your attention another time.  She may have had a cerebral event or mild stroke from what the other video showed.  But we like this one, because it is subtle and much more likely what you are going to see day to day in your world.

We see here on the video a left sided circumducting gait.  What this means is that the left limb is not swinging purely through the sagittal plane from heel lift-toe off phase to repeat heel strike again.  Instead we see the foot sweep laterally. The foot moves immediately into an increased progression angle (turned out), and it sweeps around a half circular motion to repeat the contact phase again at heel strike.

In this case here it is clearly evident, especially on the lateral side view, that she is blocked out of left ankle rocker (dorsiflexion) for some reason. She does not even get to 90 degrees dorsiflexion range at the ankle mortise.  She can no longer allow the treadmill to draw her left foot backwards because she hits this limitation.  As the limitation is met, the foot must come forward now (because it cannot go anywhere else, certainly not backwards). But, she does not display enough right gluteus medius use to create hiking of the left hip to create the clearance necessary for this premature forward left leg swing.  Thus, she has to spill the left leg out to the side in a circular-circumducting fashion to clear the limb from hitting the ground.  She is also likely doing it because if you are not able to dorsiflex the ankle, you will be relatively plantarflexed at the ankle.  And if you are plantarflexed, you are much more likely to catch your toe on the treadmill-ground during the swing through phase. This case is a problem of not creating sufficient clearance for the left foot. 

Also take note of the subtle foot drop on the left. The foot cannot maintain adequate dorsiflexion, due to weakness of the anterior compartment (possibly from a cerebral event?). Did you see the lack of inversion of the left foot as well. This is usually accomplished by the tibialis anterior and long extensors, especially EHL, neither of which is seen (take a look at the amount of hallux extension on the R on the lateral view and compare it with the left). How about that subtle midfoot collapse as well?

There are other reasons for a circumducting gait.  This is just one.  Some are functional limitations, some are ablative orthopedic type limitations such as post surgical, some are neurological, and some are a combination.  Taking a good history, knowing your gait parameters and assimilating the information will bring you to an answer.

Then you have to figure out what to do.  In this case, we do not know, because we do not know what parameter is causing the compensation you see here.  This is a good case of “what you see is not what is wrong, you are just seeing what they are doing while working around limitations and finding parts to use and cheat with” to still be able to more forward.

We are The Gait Guys, —- Ivo and Shawn

Kicking gait?

And now… A question from a reader….

 Dr Allen- There are a few questions troubling me. The first one concerns the loss of the ankle rocker phase of gait which can have implications further up the kinetic chain. It concerns the interplay of gastroc and soleus. Is it possible for gastrocnemius to work as a knee extensor when the foot is in the closed chain position - especially if the bodies centre of mass has advanced in front of the knee joint ? Thanks - RB

Hi RB_____,

yes it is possible…….it is a retrograde movement as you have described.
it is not commonly seen, but can be, and usually manifests itself, in one of 2 ways.

Typically the client is more ligamentously lax than others……..and they tend to have a “kicking” type gait, where they thrust the leg out in front, like kicking a ball, with each step forward. This causes a heavy heel strike and locks the knee in preparation for midstance, and then follows your thinking. By the way, this client also seems to like standing in a hyperextended knee position at rest.

We remember that the gastroc soleus group begins to fire in the first 10% of stance phase (it is acting as a knee extensor here); to promote eccentric deceleration of the forward moving tibia, and continues to fire until terminal swing. It is believed the soleus provides much of the deceleration force and the gastroc assists in inverting the ankle at midstance and primarily flexes the knee at pre swing, just prior to toe off (Nordin, Frankel 2001). If the gastroc /soleus group fires prematurely, or excessively, particularly in prior to midstance, then we see the action you describe, and it manifests itself as premature heel rise and loss of ankle rocker.

A sudden hyperextesion at midstance or later, in a neurologically competent individual, is unlikely, as he force is too abrupt at this point and there is too much of a mechanical disadvantage.

We hope this helps explain things a bit. Please email us back if it doesn’t!

Uber Geeks, Shawn and Ivo