Pronation as a shock absorber

Here, we talk about the 5 shock absorbing mechanisms built into the lower extremity

Forefoot Pronation

Here we discuss a runner with forefoot virus and some of the pitfalls

Projecting, calculating, the next step.

Researchers have discovered that we most accurately hit targets when we see them 1 to 1.5 steps ahead of where we were. This is more difficult that it seems because we are making a plan, and at the same time we're making that plan, we're making a movement based on the stuff that we saw a second and half in the past according to the article by Erica Pandey.

Below this link, you will find our post on projecting and estimating steps. Much along the same lines but with a great video to set it up. Here is a lead in to that article we wrote long ago, on the strange steps at a Brooklyn subway station that everyone was tripping on.

 "At Brooklyn’s 36th Street subway stop, one of the steps is slightly higher than the others. Stairs have a standardized Rise and Run and when this is altered, specifically the Rise, funny things happen. Filmmaker Dean Peterson set up his camera to capture the stumbles and the video can be seen here http://vimeo.com/44807536 and above on our blog.

The dangerous step, it turns out (which has since this video been repaired), is apparently a half-inch higher than the others. Stairway design guidelines vary within a small range.  Guidelines call for risers to be a minimum of 6 inches and a maximum of 7 ¾ inches. The allowable variance between steps is 3/8 of an inch depending on the source you seek."   Read on  . . . . . 

https://thegaitguys.tumblr.com/post/44642195883/the-funny-problem-with-the-stairs-at-brooklyns

"When walking, the brain leads the body by one step" -Erica Pandey

https://www.axios.com/we-plan-one-step-ahead-when-we-walk-scientists-say-2465394429.html

Party over the Weekend?

So, the more you drink, the more you impair the CNS. The more you impair the CNS, the more dependent you become on peripheral mechanisms. A good reason to keep your vestibular system (alcohol changes the specific gravity of the endolymph), your visual system (long term use affects the option nerve directly and can cause involuntary saccades) and proprioceptive systems including the cutaneous mechanoreceptors (because you are relying on them more) intact. Watch what and how much you drink...

"Standing postural stability relies on input from visual, vestibular, proprioceptive and mechanoreceptive sensors. When the information from any of these sensors is unavailable or disrupted, the central nervous system maintains postural stability by relying more on the contribution from the reliable sensors, termed sensory re-weighting. Alcohol intoxication is known to affect the integrity of the vestibular and visual systems. The aim was to assess how mechanoreceptive sensory information contributed to postural stability at 0.00% (i.e. sober), 0.06% and 0.10% blood alcohol concentration (BAC) in 25 healthy subjects (mean age 25.1 years). The subjects were assessed with eyes closed and eyes open under quiet standing and while standing was perturbed by repeated, random-length, vibratory stimulation of the calf muscles. Plantar cutaneous mechanoreceptive sensation was assessed for both receptor types: slowly adapting (tactile sensitivity) and rapidly adapting (vibration perception). The correlation between recorded torque variance and the sensation from both mechanoreceptor types was calculated. The recorded stability during alcohol intoxication was significantly influenced by both the tactile sensation and vibration perception of the subjects. Moreover, the study revealed a fluctuating association between the subjects' vibration perception and torque variance during balance perturbations, which was significantly influenced by the level of alcohol intoxication, vision and adaptation. Hence, one's ability to handle balance perturbations under the influence of alcohol is strongly dependent on accurate mechanoreceptive sensation and efficient sensory re-weighting. 

Modig F, Patel M, Magnusson M, Fransson PA.Study II: mechanoreceptive sensation is of increased importance for human postural control under alcohol intoxication. Gait Posture. 2012 Mar;35(3):419-27. doi: 10.1016/j.gaitpost.2011.11.001. Epub 2011 Dec 27.
weighting.

We hope you are standing up while you read this….

A newborn’s brain is only about one-quarter the size of an adult’s. It grows to about 80 percent of adult size by three years of age and 90 percent by age five (see above). This growth is largely due to changes in individual neurons and their connections, or synapses.

The truth is, most of our brain cells are formed at birth, In fact, we actually have MORE neurons BEFORE we are born. It is the formation of synapses, or connections between neurons, that actually accounts for the size change (see 1st picture above). This is largely shaped by experience and interaction with the environment.

Do you think children’s brains are less active than adults? Think again, your 3 year old’s brain is twice as active as yours! It isn’t until later in life that you actually start dialing back on some of those connections and those pathways degenerate or fade away…a process scientists call “pruning”.

How does this apply to gait? Gait depends on proprioception, or body position awareness. Your brain needs to know where your foot is, what it is standing on and so on. Proprioception, as we have discussed in other posts, is subserved by muscle and joint receptors called mechanoreceptors (muscle spindles, golgi tendon organs and type 1-4 joint mechanoreceptors to be exact). This information is fed to 2 main areas of the brain: the cerebral cortex and the cerebellum. These 2 parts of the central nervous system are interconnected on many levels.

The cerebellum is intimately associated with learning. Try this experiment. you will need a tape recorder (guess we are showing our ages, digital recorder), a timer and a moderately difficult book.

Sit down and pick a section of the book to read. start the recorder and timer and read aloud for 2 minutes. Stop reading, stop the recorder and stop the timer.

Stand up, somewhere you won’t get hurt if you fall. Stand on 1 leg (or if available, stand on a BOSU or rocker board). Open the book to a different spot. Start the timer, the recorder and start reading again for 2 minutes.

Sit back down and grab a snack. Listen to the 2 recordings and pay attention to the way you sound when you were reading, the speed, fluency and flow of words. Now think about recall. Which passage do you remember better?

The brain works best at multitasking and balance and coordination activities intimately affect learning. Having children sit in a class room and remain stationary and listen to a lecture is not the best way to learn. We always tel our students to get up and move around…

This article looks at this relationship in a slightly different way.

We hope you are still standing : )

 Lopes VP, Rodrigues LP, Maia JA, Malina RM.Motor coordination as predictor of physical activity in childhood. Scand J Med Sci Sports. 2011 Oct;21(5):663-9. doi: 10.1111/j.1600-0838.2009.01027.x. Epub 2010 Mar 11

Abstract

This study considers relationships among motor coordination (MC), physical fitness (PF) and physical activity (PA) in children followed longitudinally from 6 to 10 years. It is hypothesized that MC is a significant and primary predictor of PA in children. Subjects were 142 girls and 143 boys. Height, weight and skinfolds; PA (Godin-Shephard questionnaire); MC (Körperkoordination Test für Kinder); and PF (five fitness items) were measured. Hierarchical linear modeling with MC and PF as predictors of PA was used. The retained model indicated that PA at baseline differed significantly between boys (48.3 MET/week) and girls (40.0 MET/week). The interaction of MC and 1 mile run/walk had a positive influence on level of PA. The general trend for a decrease in PA level across years was attenuated or amplified depending on initial level of MC. The estimated rate of decline in PA was negligible for children with higher levels of MC at 6 years, but was augmented by 2.58 and 2.47 units each year, respectively, for children with low and average levels of initial MC. In conclusion MC is an important predictor of PA in children 6-10 years of age.

Some Basic Tenets of Gait

Initial contact? Loading response? Mid stance? Terminal Stance? pre swing? Are these terms that are familiar to you? Hmmm. How about the wrong orthotic for someone with internal tibial torsion? Join us in this excerpt from a recent Gait and Needling seminar

https://vimeo.com/226733697

Effects of too much of a good thing.

Classical decomposition of gait after you have a few too many for far too long. Unfortunately, taken to excess, these changes can be permanent, rather than transient in the less frequent imbiber. Be careful how you conduct your own, personal research : ) Be careful out there...

"Our results revealed several significant findings: (1) stability declined much faster from alcohol intoxication between 0.06% and 0.10% BAC (60-140%) compared with between 0.0% and 0.06% BAC (30%); (2) sustained exposure to repeated balance perturbations augmented the alcohol-related destabilization; (3) there were stronger effects of alcohol intoxication on stability in lateral direction than in anteroposterior direction; and (4) there was a gradual degradation of postural control particularly in lateral direction when the balance perturbations were repeated at 0.06% and 0.10% BAC, indicating adaptation deficits when intoxicated. "

Modig F, Patel M, Magnusson M, Fransson PA. Study I: effects of 0.06% and 0.10% blood alcohol concentration on human postural control. Gait Posture. 2012 Mar;35(3):410-8. doi: 10.1016/j.gaitpost.2011.10.364. Epub 2011 Dec 24.

Podcast 126: Running, Athletes & MTSS (Medial Tibial Stress Syndrome)

Key tag words:
running, gait, injuries, achilles tendon, CRIPSR, swearing, limbic system, MTSS, stress fractures, tibial stress fracture, medial tibial stress syndrome, shoe drop, treadmill running, treadmills, barefoot, cortisone, cartilage loss, runners, marathons

Plus a plethora of other great running geeky stuff, clinical pearls, swearing, why not to use cortisone injections and more !

Podcast location links:

http://traffic.libsyn.com/thegaitguys/pod_126fmp3.mp3

http://thegaitguys.libsyn.com/podcast-126-running-athletes-mtss-medial-tibial-stress-syndrome

http://directory.libsyn.com/episode/index/id/5563258

Our Websites:
www.thegaitguys.com

summitchiroandrehab.com   doctorallen.co     shawnallen.net


Our website is all you need to remember. Everything you want, need and wish for is right there on the site.
Interested in our stuff ? Want to buy some of our lectures or our National Shoe Fit program? Click here (thegaitguys.com or thegaitguys.tumblr.com) and you will come to our websites. In the tabs, you will find tabs for STORE, SEMINARS, BOOK etc. We also lecture every 3rd Wednesday of the month on onlineCE.com. We have an extensive catalogued library of our courses there, you can take them any time for a nominal fee (~$20).
 
Our podcast is on iTunes, Soundcloud, and just about every other podcast harbor site, just google "the gait guys podcast", you will find us.
 
Show Notes:

Implantable computer chips will control your body’s movement
http://nypost.com/2017/05/16/implantable-computer-chips-will-control-your-bodys-movement/?utm_campaign=partnerfeed&utm_medium=syndicated&utm_source=flipboard

ANU researchers grow brain cells on a chip that can be used for neural implants
http://tech.firstpost.com/news-analysis/anu-researchers-grow-brain-cells-on-a-chip-that-can-be-used-for-neural-implants-376218.html

How Scientists Think CRISPR Will Change Medicine
http://time.com/4764488/crispr-genomic-technology/

'Exercise-in-a-pill' steps closer with new study
http://www.medicalnewstoday.com/articles/317263.php

Swearing can boost muscle strength and stamina, scientists claim
http://www.mirror.co.uk/lifestyle/health/swearing-can-boost-muscle-strength-10358340

MTTS: medial tibial stress syndrome
https://www.thegaitguys.com/thedailyblog/2017/5/2/medial-tibial-stress-syndrome-mtss-and-the-long-flexor-of-the-big-toe

Corticosteriod coffin
Effect of Intra-articular Triamcinolone vs Saline on Knee Cartilage Volume and Pain in Patients With Knee OsteoarthritisA Randomized Clinical Trial

Timothy E. McAlindon, DM, MPH1; Michael P. LaValley, PhD2; William F. Harvey, MD1; et al

https://twitter.com/JAMA_current/status/864631934483345408

http://jamanetwork.com/journals/jama/fullarticle/2626573?utm_source=TWITTER&utm_medium=social_jn&utm_term=901304561&utm_content=content_engagement|article_engagement&utm_campaign=article_alert&linkId=37665463

Achilles Tendon Load is Progressively Increased with Reductions in Walking Speed.
http://journals.lww.com/acsm-msse/Abstract/publishahead/Achilles_Tendon_Load_is_Progressively_Increased.97204.aspx

Shoe drop has opposite influence on running pattern when running overground or on a treadmill.   Nicolas Chambon et al
https://link.springer.com/article/10.1007%2Fs00421-014-3072-x

So, what DOES cause a change in strike pattern with barefoot running?

We kinda thought so...

"CONCLUSION: Superficial cutaneous sensory receptors are not primarily responsible for the gait changes associated with barefoot running."

So what is? Most likely they play a part, but the joint and muscle mechanoreceptors that we had been talking about here on The Gait Guys for the last several years most likely play a larger role. The cutaneous receptors appear to play a role in general sensation, balance and coordination as well as coordination of upper extremity movements.

Thompson MA, Hoffman KM.Superficial plantar cutaneous sensation does not trigger barefoot running adaptations.Gait Posture. 2017 Jun 27;57:305-309. doi: 10.1016/j.gaitpost.2017.06.269. [Epub ahead of print]

https://www.ncbi.nlm.nih.gov/pubmed/28728130

VIDEO CASE: Is this lateral compartment weakness

Trying again here.  VIDEO CASE:  Is this lateral  compartment weakness ?
 
Quite simply, there are too many people playing doctor out there that do not have the ability to examine their clients appropriately. Here is another case of just that. 
It is clear that this client has left lateral compartment deficits. Or is it too much medial compartment tone ? Your screens and loading tests will not likely show you this specifically, this client may merely present, as they did in this case of left frontal plane hip-pelvis drift and a right cross over step.  If you have been with us for awhile, you know these 2 match up when it comes to locomotion. But one must solve the "Why" for the "how" to be accurate (how to fix it).  
But, if you are looking for weakness, you will find it here, yes, peronei and lateral gastroc are weak. But is it inhibition or neurologic or frank weakness ?  It is because of heightened medial compartment tone ? It could be, thus making one think of possible centrally mediated processes. 
And, is the ankle the source or the frontal plane drift (glute weakness) the source ? Cart or the horse ? Chicken or the egg ?  You have to examine your clients, on and off their feet, shoes off, socks off (yes, i took the socks off afterwards). Screens are not enough if you are trying to solve problems. Fixing how your client's improper loading is not a fix always, it could merely be teaching a compensation over a compensation to a problem.   Be smarter than the rest, get the knowledge to examine your clients deeper , and more specific, function. Then, how they are moving, and the movements that you see that you do not like, will make more sense.  
in this case, if you do not address the foot and the hip abductors and pelvis stabilizers, you lose, and so does your client as you build more strength into their asymmetry . . . .  eventually leading, possibly, to complaints.

Why some elderly take stair ascending slowly: PAD, Peripheral arterial disease.

When we think of slowing gait we think of the elderly. There is nothing new in this regard and there have been plenty of papers supporting the cognitive decline the coincides with this aging population. There is even correlation to increased fall risk, which matches up with significant  fall mortality studies.  Reduced, especially right sided, hippocampus volume and function is the current suspect in most research, and it is linked to some impairments in non-verbal memory and the slowing of gait.

Here, we see that PAD (peripheral arterial disease) can also cause a slowing of gait, particularly in stair ascent in this particular study. PAD can cause intermittent claudication pain in the calf and result in altered gait mechanics during level walking as well. The study found that those with claudication walked more slowly than healthy controls.  They also found that there was reduced vertical ground reactive forces, reduced knee extensor moment during forward continuance, reduced ankle angular velocity at peak moment and reduced ankle power generation.  They were also able to determine that the slower gait was related to the claudicated limb, that limb was the one that set the speed of gait. In other words, the system down regulated to the affected limb's capability. The study highlighted the importance of maintaining plantarflexor strength and power in those with peripheral arterial disease with effective claudication.  

Sagittal plane joint kinetics during stair ascent in patients with peripheral arterial disease and intermittent claudication.  Stephanie L. King, Natalie Vanicek, Thomas D. O’Brien
http://www.gaitposture.com/article/S0966-6362(17)30102-9/abstract?platform=hootsuite

Athletes on different surfaces: Asphalt, gravel, grass. It matters.

Hopefully you have noticed that went you are on a crushed limestone trail that your foot tends to spin and slip, kind of like being on ice, real rough ice.  Some people spin more than others but most people will notice some degree of slip or spin. For the LUCKY runner who is almost purely sagittal, they will strike the ground (more likely midfoot when the surface is a little slippery or unstable) and roll off the toe with minimal spin at the ball of the foot during toe off. They might get a little posterior slip at push off which is why we change our gait to be a little more apropulsive on slippery or unstable surfaces and why we see some hip extensor-flexor relationship problems in those that chose a limestone path to run on.
But for many, many who are not as lovely sagittal progressers as the lucky few, there can be much spin slip, typically external rotation foot slippage as we engage our glutes (external rotators) to push off. This can be a result of increased foot progression angle and many other things, but a biggie is that runners are often engaging the more economical narrow based step width, something we like to call the cross over gait (search our blog for dozens of references). When we have a narrow step width, our foot knee and hip are not stacked, the foot is inside the hip width spacing at foot contact. This means our foot attacks the ground with more supination, and thus more pronation afterwards and these accentuations engage more of the frontal and rotation axes in the foot, ankle and the lower limb. This can lead to more aggressive progression to high gear toe off (medial tripod) and thus an induced spin.  And so, when you engage frontal and rotational axes when you are moving forward on a slippery surface, spin results at the contact interface, more spin than we want, and that means changes in the ground reactive events leading to apropulsive gait mechanics and other nasty things we do not want such as toe gripping and clenching, a futile febble attempt to gain better purchase on the ground (in fact a useless strategy, because your foot interfaces with the sock liner of the shoe first, the sole of the shoe doesn't get to see it).
If you are a slipper, head for the asphalt road, so that you do not engage the apropulsive gait cycle biomechanics that can lead to a myriad of attempted stabilization co-contractions, quite frequently in the hip and pelvis stabilizers as one tries to nullify some of the excessive rotation in the limb-foot.  At the very least, mix up your running surfaces, give your body the exposure to variable surfaces, and as this article suggests, different motor patterns and strategies. It just might make you more durable.

-Shawn and Ivo, the gait guys

From the Dolenec study:
"Six male and two female runners participated. The participants ran at a freely chosen velocity in trials on asphalt while in trials on gravel, and grass surfaces they were attempting to reach similar velocities as in the trials on asphalt. Muscle activation of the peroneus brevis, tibialis anterior, soleus, and gastrocnemius medialis of the right leg was recorded. Running on asphalt increased average EMG amplitude of the m. tibialis anterior in the pre-activation phase and the m. gastrocnemius medialis in the entire contact phase compared to running on grass from 0.222 ± 0.113 V to 0.276 ± 0.136 V and from 0.214 ± 0.084 V to 0.238 ± 0.088 V, respectively. The average EMG of m. peroneus brevis in pre-activation phase increased from 0.156 ± 0.026 V to 0.184 ± 0.455 V in running on grass in comparison to running on gravel. Running on different surfaces is connected with different activation patterns of lower leg muscles. Running on asphalt requires stiff ankle joints, running on gravel requires greater stability in ankle joints, while running on grass is the least demanding on lower leg muscles."

Coll Antropol. 2015 Jul;39 Suppl 1:167-72.

Activation Pattern of Lower Leg Muscles in Running on Asphalt, Gravel and Grass.

Dolenec A, Štirn I, Strojnik V.
https://www.ncbi.nlm.nih.gov/pubmed/26434026