Gait Gaff Time.

(Gaff: verb tr. (to stand or take the gaff) To receive severe criticism; to endure hardship.

The Foot Slap Gait Style:  

This is a funny little video that shows a few important points.

Remember, our purpose here is to help train your eyes to the important things.  We used to use slow/stop frame digital gait software programs to slow down the person to look for particular components of failure in the gait or running cycle. After many years of doing this, we found more and more that even before we could fire up the video camera and software that we had trained our eye to see these deficits.  This is because, there are multiple clues in every gait compensation.  There is head movement (which we will discuss in this case), there is arm swing (is it equal and symmetrical, topics we have posted research articles on in the last 48 hours on this blog), torso rotation, hip lateral sway in the frontal plane, violations of sagittal knee progression, and then the always difficult multiplanar foot and ankle motions as well as so many other parameters we consider.  So, when one component goes wrong, with enough experience and skill, one can make predictions as to what is wrong.  And, the more flaws (correlative compensations) that are noted, the higher the predictive value of the assumption.  Now, many will say to us that there is no way one can do this, and that is ok.  To each his/her own.  But, after decades of doing this, as with anything, a skill is developed and an art to doing it begins to take shape, as we will see here (without stop frame, without foot mapping devices etc).  One begins to form a mental algorithm to the process.  We always start with, “is the head silent in the vertical, frontal and sagital plane?”.  When a person’s gait is off, the head is almost never silent in space.  And arm swing also begins an assymetrical pendulum effect.  This could be called an energy conservation mode (as talked about in the article on the blog entitled, Dynamic Arm Swing in Human Walking, (http://www.ncbi.nlm.nih.gov/pubmed/19640879) where it was determined that normal arm swinging required minimal shoulder torque, while volitionally holding the arms still required 12% more metabolic energy. Among measures of gait mechanics, vertical ground reaction moment was most affected by arm swinging and increased by 63% without it.

  So, as  you do this more and more you will develop the skills of observation to improve the art form of assessing one’s gait.  But remember this KEY POINT *** what you see is mere information gathering, it is not always and frequently ever, the problem that you see.  You are seeing their compensation pattern around some neurologic, orthopedic or biomechanical problems…..things that are making a silent pristine gait impossible.  You MUST then, take this information and correlate it to your clinical findings in terms of neuro-orthopedic-biomechanical limitations during your exam.  Things like, joint range limitations, muscle weakness, instabilities and the like. So, you are trying to take what you see, and what you find, and develop a logical algorithm as to where their problem lies and one that tells a logical mechanical story as to the gait pattern you are seeing.  For example, a person comes to see you with a lurching forward of their body mass onto the right leg, abruptly skipping over the heel strike phase of gait on the right causing a slap of the right forefoot onto the ground.  One option of thought COULD be a deficit in the right tibialis anterior, that being eccentrically weak in that muscle thus delivering an abrupt right foot drop type gait.  But your examination on the table, your CLINICAL examination, shows a LEFT hallux limitus with dorsiflexion range shy of the key 45 degrees needed for normal toe off.  You then have a clinical epiphany that they are leaving the left foot quickly and prematurely because THEY HAVE NO OTHER CHOICE because it hurts to load that first MTP joint on the left.  You then go down, determine the joint is limited in range, it is painful, there is a pinch callus on the medial hallux and the extensor hallucis longus and brevis are weak.  Gait analysis is done. What you saw, was not the problem, it was their compensation.  Now, you have to try and fix the problem and the compensations…….and treatment begins.

OK, soap box aside………

lets build on that skill set we are trying to develop, the powers of observation and what they COULD mean.

THE SKUNK FU GAIT:

The first thing we see is, the Sagittal head bob.…..each step there is a propulsive head anterior oscillation and then dropping downwards at the end. This can mean there is an apropulsive problem in midstance such as loss of ankle rocker but that is not so in this case, the ankle rocker is great.  The head drop in this case coincides with successive heel strikes each time.  This in essence means that they are dropping from a height each time.  How can this be ? The little fella is on flat ground ! (more on this in a minute).  This could mean a lack of core maintenance in the late midstance phase of gait (heel rise-toe off) and subsequent movement onto the next heel strike.  This can come from overstriding, as in this case, but it can also come from an aggressive forward lean in a person’s gait style (like walking into a strong head wind).  In this case, we have a more reasonable ASSUMPTION, it comes back to the “falling from a height issue”. In this case, lack of adequate anterior compartment lower limb strength (tibialis anterior and the long and short toe extensors, EDL, EDB, EHL, EHB) allows PEPE to move from heel strike to foot flat in an uncontrolled and abrupt fashion.  When this occurs, pronation (even the normal amount of pronation) occurs fast.  And we know that when a person moves from supination to pronation there is a drop in height of the arch and thus a drop in the body (try this to prove the point, …..stand up straight, look in a mirror and begin raising up your toes and then dropping them.  If you do it right, each rise of the toes should raise the arch (The Windlass Effect), and each fall should drop the arch demonstrated in the mirror by a rise and fall of the head vertically.)  And so here you have the height differential in this case.  So, in a nutshell, PEPE is over-striding (as evidenced by his also aggressive arm swing), and falling hard from  heel strike abruptly into foot flat, a double whammy !  There is basically zero eccentric phase activity of the lower anterior compartment musculature and so the foot accelerated to the ground from its starting peak height at heel strike.  The poor fella probably has a raging anterior shin splint condition because of this but you would be hard to tell from the smile on the little stinkers face.  …………but remember, prove your facts on the table……who knows, maybe he has posterior column spinal cord disease, but an examination will have to be done to confirm your findings and suspicions.  In this case, we highly recommend an upwind exam table and plenty of air fresheners. 

we remain,…  The Gait Guys

Hip internal rotation

Q: why do The Gait Guys test for internal hip rotation loss with the client supine and leg straight ?
A: because this is as close as you can get to representing midstance phase of gait where they are converting from external rotation at rearfoot strike to moving through the pronatory phase where internal limb rotation is paramount. A loss on the table is a key exam finding ! it must be listened to.

* key……the leg is straight at zero degress of leg raise……ie. the leg is flush on the table. if you lift the leg…..you have effectively put them more in early midstance…..ideally you would love to drop them a bit further into hip extension to see if you can get the internal rotation with hip extension which would represent the approach to toe off.

Q: so what are the internal hip rotators you would check functionally then to find out who is inhibited (& could be related to loss of the range ?)
A: lower TVA, anterior G. Med, TFL, v. lateralis, rectus femoris, lateral hamstrings, coccygeal g. maximus, iliocostalis T/L paraspinals…….to start with. Find me one that is weak and i will show you one that might get them more internal hip rotation.

Arm Swing privides clues to gait pathology

Arm swing provides clues to gait pathology. We always talk about arm swing as a compensation mechanism. Here arm swing is used to increase hip extension in individuals that want to limit rotation of the lumbar spine.

 

http://www.ncbi.nlm.nih.gov/pubmed/21181483

get the article !

 

Eur Spine J. 2011 Mar;20(3):491-9. Epub 2010 Dec 24.

Gait adaptations in low back pain patients with lumbar disc herniation: trunk coordination and arm swing.

Huang YP, Bruijn SM, Lin JH, Meijer OG, Wu WH, Abbasi-Bafghi H, Lin XC, van Dieën JH.

Source

Department of Orthopaedics, First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 35005, People’s Republic of China.

Abstract

Patients with chronic non-specific low back pain (LBP) walk with more synchronous (in-phase) horizontal pelvis and thorax rotations than controls. Low thorax-pelvis relative phase in these patients appears to result from in-phase motion of the thorax with the legs, which was hypothesized to affect arm swing. In the present study, gait kinematics were compared between LBP patients with lumbar disc herniation and healthy controls during treadmill walking at different speeds and with different step lengths. Movements of legs, arms, and trunk were recorded. The patients walked with larger pelvis rotations than healthy controls, and with lower relative phase between pelvis and thorax horizontal rotations, specifically when taking large steps. They did so by rotating the thorax more in-phase with the pendular movements of the legs, thereby limiting the amplitudes of spine rotation. In the patients, arm swing was out-of phase with the leg, as in controls. Consequently, the phase relationship between thorax rotations and arm swing was altered in the patients.

Arm Swing Matters !

Arm swing matters! “The data thus suggest that the motor cortex makes an active contribution, through the corticospinal tract, to the ongoing EMG activity in arm muscles during walking.” Appropriate afferent feedback loops (from the joints in the upper and lower extremities) are necessary for the brain to run this motor engram; so if gait is altered, so are those feedback loops. You are witnessing a CORTICAL phenomenon! It’s about a lot more than pronation!

http://www.ncbi.nlm.nih.gov/pubmed/20123782

get the article !!!

J Physiol. 2010 Mar 15;588(Pt 6):967-79. Epub 2010 Feb 1.

Corticospinal contribution to arm muscle activity during human walking.

Barthelemy D, Nielsen JB.

Source

Department of Exercise and Sport Science, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen, Denmark.

Abstract

When we walk, our arm muscles show rhythmic activity suggesting that the central nervous system contributes to the swing of the arms. The purpose of the present study was to investigate whether corticospinal drive plays a role in the control of arm muscle activity during human walking. Motor evoked potentials (MEPs) elicited in the posterior deltoid muscle (PD) by transcranial magnetic stimulation (TMS) were modulated during the gait cycle in parallel with changes in the background EMG activity. There was no significant difference in the size of the MEPs at a comparable level of background EMG during walking and during static PD contraction. Short latency intracortical inhibition (SICI; 2 ms interval) studied by paired-pulse TMS was diminished during bursts of PD EMG activity. This could not be explained only by changes in background EMG activity and/or control MEP size, since SICI showed no correlation to the level of background EMG activity during static PD contraction. Finally, TMS at intensity below the threshold for activation of corticospinal tract fibres elicited a suppression of the PD EMG activity during walking. Since TMS at this intensity is likely to only activate intracortical inhibitory interneurones, the suppression is in all likelihood caused by removal of a corticospinal contribution to the ongoing EMG activity. The data thus suggest that the motor cortex makes an active contribution, through the corticospinal tract, to the ongoing EMG activity in arm muscles during walking.

Dynamic arm swinging in human walking.

It pays, metabolically and biomechanically, to swing your arms! “Experimental measurements of humans (n = 10) showed that normal arm swinging required minimal shoulder torque, while volitionally holding the arms still required 12 per cent more metabolic energy. Among measures of gait mechanics, vertical ground reaction moment was most affected by arm swinging and increased by 63 per cent without it.”


Get the article !

http://www.ncbi.nlm.nih.gov/pubmed/19640879
Proc Biol Sci.
2009 Oct 22;276(1673):3679-88. Epub 2009 Jul 29.

Dynamic arm swinging in human walking.Collins SH, Adamczyk PG, Kuo AD.

Source

Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109-2125, USA. shc@umich.edu

Abstract

Humans tend to swing their arms when they walk, a curious behaviour since the arms play no obvious role in bipedal gait. It might be costly to use muscles to swing the arms, and it is unclear whether potential benefits elsewhere in the body would justify such costs. To examine these costs and benefits, we developed a passive dynamic walking model with free-swinging arms. Even with no torques driving the arms or legs, the model produced walking gaits with arm swinging similar to humans. Passive gaits with arm phasing opposite to normal were also found, but these induced a much greater reaction moment from the ground, which could require muscular effort in humans. We therefore hypothesized that the reduction of this moment may explain the physiological benefit of arm swinging. Experimental measurements of humans (n = 10) showed that normal arm swinging required minimal shoulder torque, while volitionally holding the arms still required 12 per cent more metabolic energy. Among measures of gait mechanics, vertical ground reaction moment was most affected by arm swinging and increased by 63 per cent without it. Walking with opposite-to-normal arm phasing required minimal shoulder effort but magnified the ground reaction moment, causing metabolic rate to increase by 26 per cent. Passive dynamics appear to make arm swinging easy, while indirect benefits from reduced vertical moments make it worthwhile overall.


Near Flawless Running Technique…….it would have to be to be doing it at this pace on paved hardtop…….the first fellas techique is better, his step and strike are shorter and thus cadence is higher…….the higher the cadence, the less the acceleration/deceleration and less vertical changes.  Apparently the first chap has been running barefoot his whole life, it shows.  Nicely done boys !

We came across this video on Youtube. Look at the obvious deficiency on the right limb with the amount of internal spin of the foot.  Much can be gleaned from this information. remind you that making assumptions of what is wrong or what the treatment is from what you see on a treadmill or in a person walking or running may not be their actual problem, rather it is quite often their compensation pattern. 

In this case, we see an aggressive negative foot progression angle on the right. Normal foot progression angle is anywhere from zero degress (see this persons left foot) up to 15 degrees depending on their given anatomy. 

This is likely from internal tibial torsion on the right but femoral torsion would need to be looked at. What is interesting is taking the concepts of what are seen here and projecting some other thoughts and considerations, as The Gait Guys always do.  This person is “toeing off” the lateral column of the foot (3rd-5th digits).  This will enforce a supinatory toe off, it is always nice to toe off a rigid lever but in time running in this case could eventually lead to some osseous stress reaction/response into these lesser metatarsals and could “couch” this person for a period. To gain more stability (plantar purchase of the foot on the ground) these clients frequently have over activity of their long toe flexors (FDL) and some toe hammering in the lateral digits is not uncommon.  Be sure to look for this phenomenon in your clients.

Toe off from the lateral foot is not uncommonly seen pairing up with a shortened step length on that side and same side knee hyperextension, reduction in ankle rocker (dorsiflexion through the tibial-talar joint) which can lead to anterior impingement at this interval as the ankle dorsiflexion is prematurely terminated,

We also frequently see a reduction in strength of the anterior compartment musculature; the ankle dorsiflexors (primarily the tibialis anterior) and toe extensors which further impairs any chance of normal ankle rocker range.  Additionally, these folks typically have weak lower abdominals on the affected side and tend to strategize through their quadriceps instead of the more effective glute-abdominal core stabilizing unit.In this case here, the more internal tibial torsion or internal spin a limb has, the less likely the client is able to engage the external hip rotators of which the gluteus maximus (iliac division) and gluteus medius (posterior division) are powerful proponents.

Lastly, for now, although this is likely a case of internal tibial torsion, it brings up the considerations in other cases that an internally rotated limb is typically shorter functionally and thus this can lead to an apparent leg length discrepancy.

These are all great “mental exercises” to keep your eyes and brain keen. But as we always say, what you may see may not be so.  Be sure to test your muscles and motor patterns to see if what they are displaying is their deficiency or their compensation pattern, or a bit of both. 

The Gait Guys , Shawn and Ivo

The Hokaone: Hoka or Hokey? http://www.hokaoneone.com/en/technology.html We have been off the grid for a week amassing new research for the website and looking into new products that have come online recently. But we are back now with new stuff.  Le…

The Hokaone: Hoka or Hokey?

http://www.hokaoneone.com/en/technology.html
We have been off the grid for a week amassing new research for the website and looking into new products that have come online recently. But we are back now with new stuff.  Lets start today on this shoe, the Hoka.


From their website “ By using an EVA 30% softer and increasing its total volume to 2.5 times that of a typical trail running shoe, we allow for more cushioning than any other shoe on the market today, dissipating up to 80% of the shock associated with heel striking when running. Allowing for as much as 20mm of compression in the heel, with a low ramp angle allows for tremendous confidence running downhill, as runners can now engage their gluteus and lower back as opposed to isolating their quads, relaxing the body and making running downhill fun and comfortable.”

 What we like:
1-A low ramp angle definitely helps one to engage their glutes more.
2- light weight is often a good thing

What we don’t like:
There have been enough papers published that show increased cushioning decreases impact at heel strike, but increases overall impact forces sustained by the body. A thickened sole decreases the amount of proprioception and requires the body to work harder by compressing more of the EVA foam, and with this shoe, that will be quite a bit of body work.

A little sole rocker off the front endcan be a good thing, especially with people who lack great toe dorsiflexion, but enough to take up 50% of the sole length and 4 cm high? Wow ! This would decrease the amount of forefoot rocker and subtract from the 3 rockers that the foot was normally designed to work with (heel, ankle and forefoot). The research (which at least we have read) shows that rockered shoes increase knee flexion during the first part of the stance phase of ambulation, and less in swing phase. More significantly, ankle plantarflexion is increased at heelstrike through terminal stance, thus delaying pronation (plantar flexion, inversion and adduction are components of supination); this would dampen the shock absobtion afforded from pronaion and lowering of the ankle mortise. Interestingly, this increases the impact force at heel strike significantly as well.

“With 50% more surface area than the typical trail running shoe, and 35% more rubber crampons, you’ve never run as confidently as you will in a pair of Hoka’s.” Hmm. Doesn’t a larger footprint, especially at the midfoot, hamper the natural dampening mechanism of pronation? What about the increased mechanical requirements to move the extra sole? Sure, it will be more stable, but at the cost of mechanical efficiency.

Take a look at the break points on the undersole; Why put a break directly under the calcaneus and then one immediately anterior (under the sustantaculum tali) at a 90 angle to the plane of the joint? The ones across the transverse metatarsal arch proximally are in an arc OPPOSITE the plane  of  the articulations; it seems to us that this would cause mechanical conflict at the metatarsophalangeal joints; the distal ones seem more appropriate, but the ones anterior to that serve to abduct the phalanges.


Summary:

In a nutshell ? We are sure this is a supercomfy foot spa that feels like walking on marshmallows but we question the science behind the design and would welcome the opportunity to review their research or even to trial a pair.

We think you will find that what we  have addressed here merit some attention by everyone.  As we always say though, every product has some uses and purpose, but also some drawbacks.  Do your own homework though, go to their website…… http://www.hokaoneone.com/en/technology.html

Once again, We are and remain,…… The Gait Guys

Clinical Video Case Study: Tibial Varum with added Post-op ACL complications.

This is a case of ours. This young man had a left total knee reconstruction (Left ACL and posterolateral compartment reconstruction; allograft ligaments for both areas). This video is roughly 3 months post surgery.

Q: What anatomical variants are seen in this individual?

A: Note the genu and tibial varum present. This results in an increased amount of pronation necessary (right greater than left, because of an apparent Left sided short leg length;

* NOTE: post-operatively at this point the client had still some loss of terminal left knee extension. thus the knee was in relative flexion and we know that a slightly flexed knee appears to be a shorter leg. Go ahead, stand and bend your left knee a few degrees, the body will present itself as a shorter leg on that left side with all the body compensations to follow such as right lateral hip shift and left upper torso shift to compensate to that pelvic compensation.)

Normally, in this type of scenario (although we have corrected much of it at this point by giving him more anterior compartment strength and strategy as evidenced by his accentuated toe extension and ankle dorsiflexion strategies, these are conscious strategies at this point for the patient), the functionally shorter left leg has a body mass acceleration down onto it off of the longer right leg stance phase of gait. This sagittal (forward) acceleration is met by a longer stride on the right with an abrupt heel strike (in other words, the client is moving faster than normal across the left stance phase so there is abrupt and delayed heel strike on the right because of a step length increase. (again, this is just commentary, had we videoed this client weeks before this, you would have seen these gait pathologies. This video shows him ~70% through a gait corrective phase with us.)

Again, this client has bilateral tibial varum. You can see this as evidence due to the increased calcaneal valgus (ie. rearfoot pronation; look at the achilles valgus presentation).
He increases his arm swing on the Left to help bring the longer Right lower extremity (relative) through.
if you look closely you can also see early right heel departure which is driven by the increased forward momentum of the body off of the short left limb. In other words, the body mass is moving forward faster than normal onto the right limb (because of the abbreviated time spend on the left “short” leg) and thus the forward propulsed body is pulling the right heel up early and the heel is spinning inwards creating a net external rotation on the right limb (look for the right foot to spin outwards/externally ever so slightly in the second half of the video).

Early heel departure means early mid and forefoot weight bearing challenges and thus reduced time to cope well with pronation challenges. As we see in this case where the right foot is pronating more heavily than the left. You can think of it this way as well, the brain will try to make a shorter leg longer by supinating the foot to raise the arch, and the longer leg will try to shorten by creating more arch collapse/pronation.

In this F-Scan film we see increased pressure on the lateral column of the foot with forces traveling to the 2nd metatarsal as they come across the foot. This is most likely due to an uncompensated forefoot varus. Note the hot spots at the 2nd and 5th met heads. This patient also has a Morton’s toe which is a longer digit.

Rule #1…..never assume. Examine your clients even after F-Scans, pedographs, stop frame digital movie etc. What you see is often not the problem, rather their adaptive compensation around the parts that are working and those that are not. The problem can be local, where it appears the deficit is, or it can be elsewhere. Let the clinical examination draw the correct conclusions. For example, in this case, we could have metatarsus primus elevatus or a Rothbart Foot variant or a combination of all of the above with the FF varus.
There is nice engagement of the hallux flexors but when you see this in combination with a preceding insufficient 1st metatarsal grounding (as evidenced here of lack of “heat” under the 1st Metatarsal) a late supination attempt may be suspected to reduce a late midstance pronation vector. Again, let your clinical examination draw the correct conclusions.

This is a case of internal tibial torsion. In particular, watch the right limb. We see a decreased progression angle of the feet, Right greater than the left, a “crossing over” gait; and bilateral toe off in supination, Right greater than the left. This can impair a persons ability to engage the lumbopelvic stabilizers adequately, impair patellofemoral tracking, and generate a host of compensatory motor patterns that are sub-optimal.

This individual’s shoe choice renders a degree of over-correction and is magnifying the problem to a degree.

The First Biodegradable Shoe

Same quality, less filling.

Ever think about what happens to that old pair of running shoes you retired or gave to the dog? It takes about 1000 years (yes, that’s 3 zeroes) for the EVA ( the midsole material in most running shoes) to break down. Brooks has come up with a nice alternative, that under the right conditions , takes 50 times less or about 20 years.

Brooks Trance 8: The First Biodegradable Running Shoe

Peter Weyand, PhD, SMU. Locomotor Performance Laboratory.

From our new friend Peter Weyand, PhD, SMU, Dallas. Southern Methodist University, Locomotor Performance Laboratory.
In the study:
The biological limits to running speed are imposed from the ground up.
J. Appl Physiol (Jan 21, 2010).
Study concluded that the stance phase limit to running speed is imposed, not by the maximum forces that the limbs can apply to the ground, but rather by the minimum time needed to apply the large, mass-specific forces necessary. So, the faster the foot applies the max force into the ground and gets that foot off the ground to do the same on the other foot, the faster the person will be able to run.

Harvard: Lieberman Studies on heel strike

Lieberman: …most experienced, habitually barefoot runners avoid heel landing & instead land forefoot or midfoot strike….most FF & some MF strikes (shod or barefoot) do not generate the sudden, large impact transients that occur with heel strike (shod or barefoot). Consequently, FF or MF strikers do not need shoes with elevated cushioned heels to cope with sudden, high transient forces that occur when you impact.

Shoes and Cushioning

…and…Shoes with cushioning fail to absorb impact when humans run and jump, and amplify force under certain conditions, because soft materials used as interfaces between the foot and support surface elicit a predictable reduction in impact-moderating behavior. This behavior is not a response to sensations directly caused by impact because, ….
….whereas barefoot humans estimate impact precisely, humans judge it inaccurately when shod. Recent reports also indicate that humans reduce impact-moderating behavior, thereby amplifying impact, when they are convinced that they are well protected by the footwear they are wearing. …accounts for the 123% greater frequency of injuries with the most expensive shoes found by Marti.18