Running cadence doesn't matter? Maybe.

Does running cadence matter? Not as much as previously thought (in terms of speed and efficiency, but this is not a comment on altering biomechanics to avoid or manage running through injury. One of the first things we ask of a runner, who insists they will be running with their injury while we attempt to get ahead of it, is to increase their cadence and land with more finesse (if they are a heavy "plunker", which often happens on longer runs when people fatigue).

“Some ran at 160 steps per minutes and others ran at 210 steps per minute, and it wasn’t related at all to how good they were or how fast they were,” Burns said. “Height influenced it a little bit, but even people who were the same height had an enormous amount of variability.”

"Another unexpected finding is that by the end of a race, cadence varied much less per minute, as if the fatigued runner’s body had locked into an optimal steps-per-minute turnover. It’s unclear why, Burns said, but this deserves further study."

https://news.umich.edu/step-it-up-does-running-cadence-matter-not-as-much-as-previously-thought/?fbclid=IwAR07mIPxVEPXlkkXoU-XxyCIQY7MwfpX0HHXW7lxMqrcx69ZHHjLO1SxPXw

Podcast 143: Future of movement, Running Cadence. Plus: gait rehab, eye control, plantar fascia talk

Topics:


Links to find the podcast:
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doctorallen.co
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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 and just about every other podcast harbor site, just google "the gait guys podcast", you will find us.

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Show notes:

The future of human movement control ?
https://www.zerohedge.com/news/2019-01-01/zuckerberg-funds-wireless-mind-control-using-game-changing-brain-implants

Really interesting study: in-race cadence data from world 100K champs. Fatigue matters less than expected;
https://www.outsideonline.com/2377976/stop-overthinking-your-running-cadence?utm_medium=social&utm_source=twitter&utm_campaign=onsiteshare

A new study shows a majority (82%) of adolescent patients presenting with FAI syndrome can be managed nonoperatively, with significant improvements in outcome scores at a mean follow-up of two years: ow.ly/GXtC30n49nc pic.twitter.com/dyr4f6pEOU

Gait Rehab
https://academic.oup.com/ptj/article/88/12/1460/2742171
" Rehabilitation of gait in PSP should also include oculomotor training because the ability to control eye movements is directly related to the control of gait and safe ambulation. Vision plays a critical role in the control of locomotion because it provides input for anticipatory reactions of the body in response to constraints of the environment. Anticipatory saccades occur normally in situations that involve changing the direction of walking17 or avoiding obstacles.18 When downward saccades are not frequently generated during obstacle avoidance tasks, there is an increase in the risk for falling. Di Fabio et al19 reported that elderly people at a high risk for falling generated fewer saccades than their low-risk counterparts during activities involving stepping over obstacles. In addition, foot clearance trajectories were asymmetric in the high-risk group, with the lag foot trajectory being significantly lower than the lead foot trajectory. Similar behavior has been observed in patients with PSP during stair-climbing activities. Di Fabio et al20 recently reported that patients with severe oculomotor limitations had a lower lag foot trajectory than those with mild oculomotor limitations. "

Eye movements:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4932064/
" The content of the eye movement program was as follows: First, a picture card was shown to the patient, and then mixed with 20 other cards and spread face up on the desk. The patient was instructed to find that one card. This task was repeated approximately 20 times. Second, the therapist moved a baton slowly while drawing curves and the patient was instructed to keep his or her gaze fixed on the tip of the baton. In this task, the distance between the baton and the patient was maintained at approximately 1 m and the task was performed for approximately five minutes. Third, the patient was instructed to shake his or her head laterally as quickly as possible and a letter card with letters written upside down was presented to the patient to read. This task was repeated approximately 10 times. Fourth, the therapist moved a baton slowly from a point approximately 5 cm away from the patient to a point approximately 50 cm away and the patient was instructed to keep his or her eyes on the baton. This task was performed for approximately five minutes. The experimental group underwent eye movement training while the control group underwent gait training for 20 minutes per session, five times per week for six months in total."

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3259492/

Plantar fascia loads higher when forefoot striking . . . .
https://www.sciencedirect.com/science/article/pii/S0021929018308959
Foot arch deformation and plantar fascia loading during running with rearfoot strike and forefoot strike: A dynamic finite element analysis
Tony Lin-WeiChen et al

High pronation was associated with 20-fold higher odds of injury than neutral foot posture
Association between the Foot Posture Index and running related injuries: A case-control study
AitorPérez-Morcillo et al
https://www.sciencedirect.com/science/article/pii/S0268003318304303

movement, gait, thegaitguys, running, cadence, step length, stride length, eye movements, rehab, gait analysis, gait problems, pronation, plantar fascia,

When one foot is shorter, and smaller. Gait thoughts to consider.

This person had a congenital “club foot” at birth also know as congenital talipes equinovarus (CTEV). It is a congenital deformity involving one or both feet. In this case it affected the right foot (the smaller one).
Foot size is often measured with the Brannock device in shoe stores, you know, the weird looking thing with the slider that measures foot length and width. In this case, the right heel:ball ratio, the length from the heel to the first metatarsal head, is shorter. The heel:toe length is also shorter, nothing like stating the obvious ! IF they are shorter then the plantar fascia is shorter, the bones are shorter, the muscles are smaller etc.

So, the maximal height of the arch on the right when the foot is fully supinated is less than that of the left side when also fully supinated (ie. during the second half of the stance phase of gait). Even with maximal strength of the toe extensors which we spoke of yesterday will not sufficiently raise the arch on the right to the degree of the left.

Thus, this client is very likely to have a structural short leg. Certainly you must confirm it but you will likely see it in their gait if you look close enough.
Also, you must remember that the shorter foot will also spend fractionally less time on the ground and will reach toe off quicker than the left. This may also play into a subtle limp.
This client may have a mal-fitting shoe, the right foot will swim a little in a shoe that fits correctly on the left. You may be easily able to remedy all issues with a cork full length sole insert lifting both the heel and forefoot. This can negate the shoe size differential, change the toe off timing and remedy much of the short leg issue. You will know that the right foot at the metatarsal-phalangeal joint bending line will not be flexing where the shoe flexes on that right foot. The Right foot will be trying to bend proximal to the siping line where the shoe is supposed to naturally bend. This will place more stress into that foot. This brings up the rule for shoe fit: never size a persons shoe by pinching the toebox to see if there is ample room, the shoe should be fit to meet the great toe bend point to the flex point of the shoe.
Strength of muscles is directly proportional to the cross sectional area of the muscle. With smaller muscles, this right limb is very likely to be underpowered when compared to the left.
All of these issues can cause a failure of symmetrical hip rotation and pelvic distortion patterning.
Altered arm swing (most likely on the contralateral side) is very likely to accommodate to the smaller weaker right lower limb. Do not be surprised to hear about low back pain or tightness or neck/shoulder issues.
A shorter right leg, due to the issues we have discussed above, will place more impact load into the right hip ( from stepping down into the shorter leg) and more compressive load into the left hip (due to more demand on the left gluteus medius to attempt to lift the shorter leg during the right leg swing phase). This will also challenge the pelvic symmetry and can cause some minor frontal plane lumbar spine architecture changes (structural or functional scoliosis…… if you want to drop such a heavy term on it).

Gait plays deeply into everything. Never underestimate any asymmetry in the body. Some part as to take up the slack or take the hit.

post link:

https://thegaitguys.tumblr.com/post/23230149195/we-could-have-easily-made-this-a-blog-post-about

Coordination of leg swing, thorax rotations, and pelvis rotations during gait: The organisation of total body angular momentum

"In walking faster than 3 km/h, transverse pelvic rotation lengthens the step (“pelvic step”).
The shift in pelvis–thorax coordination from in-phase to out of phase with increasing velocity was found to depend on the pelvis beginning to move in-phase with the femur, while the thorax continued to counter rotate with respect to the femur. "

We are always trying to bring greater understanding to this group at TGG regarding gait mechanics. One must understand the implications of rotational work, and anti-rotational work on the phasic and antiphasic nature of the thorax and the pelvis. We have talked about becoming more phasic when there is spine pain. With today's study, we delve just al little deeper, particularly noting how the pelvis and the femur moving together first, before that is offset by the antiphasic nature of the thorax at higher speeds of gait.
This article uses the terms in phase and out of phase. We have learned over time that those terms to relate more so the description of how the limbs are, or are not, pairing up when a couple is walking together. None the less, the reader here should understand how they are referring to out of phase as antiphasic.

http://www.sciencedirect.com/…/article/pii/S096663620700135X

Sagittal gait change in arthritic hips.

Asymmetries are the norm, whether they are anatomic or functional. This however does not mean that there may, or may not, be present or future consequences to the asymmetries.  It can take time for compensations to develop to accommodate these compensations, and it may take even further time for the body to present (and perhaps not present) consequences to the compensations.

In this study, progressing osteoarthritis in the hip began to eat away as some functional parameters that might otherwise have allowed for more symmetrical step and strike lengths, and one must not forget step width has to be in this discussion as well. 

"The patients walked significantly slower than the controls (p=0.002), revealed significantly reduced joint excursions of the hip (p<0.001) and knee (p=0.011), and a reduced hip flexion moment at midstance and peak hip extension (p<0.001). Differences were primarily manifested during the latter 50% of stance, and were persistent when controlling for velocity." - Eitzen et al.

Thus, to walk a straight line, some adaptive compensations will have to occur in the body to enable a linear progression. This might mean altering hip extension patterns, altering hip rotation relationships within the affected hip and thus of the contralateral hip (which might lead to pelvis distortion patterning), pelvis drift in the frontal plane, pelvis drift in the sagittal plane (APT, PPT), asymmetries in spinal rotation and thus arm swing, to name a few just regionally at the hip-pelvis-spine interval. Adaptations must be made. The question is, does your gait assessment afford you the insight to be addressing the problem, or merely their visible compensation, that is the hard part.  And remember what we always say, you gait analysis is only going to show you what your client is doing, not why they are doing it. Thus, fixing what you see is likely not fixing
"the why".

"Reduced gait velocity, reduced sagittal plane joint excursion, and a reduced hip flexion moment in the late stance phase of gait were found to be evident already in hip osteoarthritis patients with mild to moderate symptoms, not eligible for total hip replacement. " - Eitzen et al.

* Differences were primarily manifested during the latter 50% of stance, and were persistent when controlling for velocity.

https://www.ncbi.nlm.nih.gov/pubmed/23256709

BMC Musculoskelet Disord. 2012 Dec 20;13:258. doi: 10.1186/1471-2474-13-258.
Sagittal plane gait characteristics in hip osteoarthritis patients with mild to moderate symptoms compared to healthy controls: a cross-sectional study.
Eitzen I1, Fernandes L, Nordsletten L, Risberg MA.

Your gait analysis is lying to you more than you think. The more difficult motor program your client is running occurs before the gait analysis even begins.

Even before you client walks back to your treatment room, there are several things that we may not be aware of. Gait initiation is a different and more complex motor program than the simple gait motor program.

Here is a little something we do in our clinics, all the time. When the session room is open for the next client, we greet our client in the lobby. We do not have our staff send them back to the room to change and wait for us. We watch them closely, but without them knowing. How does the client stand up? How do they initiate their gait cycle ? How is their balance? How do they carry their bags, purse, backpack ?
We ask them to head back to the session room to get changed, letting them think we are grabbing a drink of water. And then, in a sneaky manner, we watch them stand, initiate gait, and walk back to the room.
We do this, because, gait initiation is separate motor program. It requires several component parts, a squat, weight shift, double support balance acquisition, COP (center of pressure acquisition), step length precalculations, step width precalculation, foot strike targeting, weight shift again, initial weight transition, and then the gait cycle. And gait initiation is different and asymmetrical in people with pain, we know this for a fact in clients with painful osteoarthritis. These clients develop adaptive posturomotor strategies that shorten the monopodal phase on the affected leg.*
For many gait disorders, these are the component parts that will first show up if there is a problem in the system. Gait initiation is more difficult than gait perpetuation. Besides, how we walk when we do not think we are being watched, when we are carrying our things (purse, phone, bottle of water, backpack, etc) is how we typically walk. Clients will show all the goodies we need to see: the turned out foot, the hiked shoulder, the limps, the staggers, stumbles, speed, step width, and the like. We also get to see how they move in the shoes they live in, the heeled ones, the broken down ones, the work shoes.

So, when your client is having a formal treadmill gait analysis, what are you seeing? Their best behavior, or the truth ? One thing is for sure, you do not see the most important program the precedes their treadmill analysis, namely, how they get out of the chair and up onto the treadmill. This stuff matters.
There are clues everywhere, grab all of them, in as natural a manner as possible.

The Gait Guys

*Arch Phys Med Rehabil. 2000 Feb;81(2):194-200.
Asymmetry of gait initiation in patients with unilateral knee arthritis.
Viton JM1, Timsit M, Mesure S, Massion J, Franceschi JP, Delarque A.

Walking: The brain leads the body by one 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.
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.

https://www.axios.com/when-walking-the-brain-leads-the-body-by-one-step-1513304440-3035f0bb-a992-403f-b084-51e4205cda58.html
https://thegaitguys.tumblr.com/post/44642195883/the-funny-problem-with-the-stairs-at-brooklyns

Step width, length and gait economy.

We have talked about step with hundreds of times it seems. We get asked all the time about optimal or proper step width in our runners, especially the ones that have a tendency to drop into the higher risk category of "cross over" gait. We like to refer them to our standard reply, "many good things happen with increasing your step width, but there is no need to go beyond the hip distance width, no wider than the hips. You should find more gluteal activation there. However, this is less economical than a narrower step width. But, the narrower the step width, you are juggling the increased economy with increased liability (for injury) and riskier biomechanics. One must earn their way into the higher economy narrow step width with gaining durability in these potentially riskier narrow step with mechanics. Failure to do so is a choice taken at your own risk." This article suggest costly risks to a narrow step width as well.

From the Shorter Abstract

"Humans tend to walk economically, with preferred step width and length corresponding to an energetic optimum. In the case of step width, it is costlier to walk with either wider or narrower steps than normally preferred. Wider steps require more mechanical work to redirect the body's motion laterally with each step, but the cost for narrower steps remains unexplained. Here we show that narrow steps are costly because they require the swing leg to be circumducted around the stance leg. And, we could not agree more. There is definitely a sweet spot for every runner, finding it, and earning the durability required to fend off injury is where the magic lies. RAther than tell your runners where to place their feet , thus you defining their step width, give your clients the appropriate hip and frontal plane stability work to find their low risk sweet spot. After all, most of the foot posturing placement is dictated from the hip and pelvis mechanics, as we have written about extensively previously.

Gait Posture. 2017 Mar 23;54:265-270. doi: 10.1016/j.gaitpost.2017.03.021.

The high cost of swing leg circumduction during human walking.

Shorter KA1, Wu AR2, Kuo AD3.

https://www.ncbi.nlm.nih.gov/pubmed/28371740

Pod 133: Two Gait Cases & their Gait Rehab

Today we discuss a few cases we have seen.  We discuss 2 cases, both involved poorly adapted gaits from injury, adaptations that had become the client's new norm. Once you get past Ivo's case presentation, which is very in depth, the discussions quickly go into very important topics that we all over look, namely gait and gait rehab, gait thresholds, metabolic thresholds, cortical fatigue, and how to use some neurologic principles to restore a problematic gait.

Key Tag words:
gait, concussion, head trauma, cortical fatigue, endurance, strength, gait analysis, gait problems, gait rehab, running, running injuries, run-walk, SCFE, slipped epiphysis, femoral growth plate, hip stress fractures, growth plate injury, hip dysplasia, limping gait, club foot, step length, stride length

Links to find the podcast:

iTunes page: https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138?mt=2

http://traffic.libsyn.com/thegaitguys/pod_133final.mp3

http://thegaitguys.libsyn.com/pod-133-two-gait-cases-their-gait-rehab

Libsyn Directory: http://directory.libsyn.com/episode/index/id/6184651

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 and just about every other podcast harbor site, just google "the gait guys podcast", you will find us.

Swing matters, too.

We speak often about the 3 foot rockers, with particular attention often to ankle rocker (ankle mortise). But one must not forget about the rear and forefoot rockers, they have their important place as well.
But, we all too often only think of these parameters when the foot is on the ground.  The truth is, the swing limb is very important as well. How we swing, how the foot prepares for initial contact is also critical. 

Last week Ivo wrote about toe walkers, a topic we have written about several times previously on our blog "The Gait Guys". 

In this study, the researchers were appearing to look at plantarflexion posturing of the foot-ankle complex. the noted that"unilateral restricted ankle motion influenced kinematics mainly in the swing phase" as we proposed. Again, swing phase is just as critical as the stance phase of gait.  One might recall our mnemonic, "when the foot is on the ground, the glutes are in charge, and when the foot is in the air, the abdominals are in charge". This admittedly is a very loose statement, but it has its place to begin the dialogue. Meaning, there is more to it.  Yes, the hip flexors are key, but they have to be active on a precursor, sufficient control of the pelvis, via the abdominals in part.  To this point, the researchers noted that, "hip and knee peak flexion in the swing phase were increased on the restricted side". Meaning, that to clear a plantarflexed foot-ankle complex, one might have to accentuate flexion elsewhere.  No rocket science here. This is the "foot drop" strategy most of us are all to familiar with. People with foot drop have an inability to dorsiflex the ankle to clear the ground in swing, thus, to avoid tripping, one has to flex the limb higher up the chain, perhaps even hike the pelvis with the opposite leg hip abductors (plus a little frontal plane lean perhaps). This article however discusses restrictions, and not what we just discussed, loss of function. 

Furthermore, "Walking with unilateral restricted ankle motion had a negative effect on walking velocity, cadence, step time, and step length."

Gait Posture. 2015 Mar;41(3):835-40. 
Immediate effects of unilateral restricted ankle motion on gait kinematics in healthy subjects.  Romkes J1, Schweizer K2.
 

https://www.ncbi.nlm.nih.gov/pubmed/25800648

Step rate to change foot strike?

Do you do gait retraining? Have you thought about manipulating step rate to change foot strike? If not, you may want to check this out. 

"The intent of our study was to determine whether step-rate manipulation alone was enough to change foot-strike pattern in shod recreational distance runners. We found increasing step rate above the runner’s preferred rate by 10% was successful in changing foot-strike pattern from a heel-strike to a midfoot- or forefoot-strike pattern in 17.5% of the runners, while increasing step rate by 15% changed foot strike pattern in 30%. These results suggest step-rate manipulation alone may be an effective way to change foot-strike pattern in a small percentage of shod distance runners."

http://lermagazine.com/…/step-rate-manipulation-and-foot-st…

A cool paper on taping and reciprocal inhibition. 

“Hip extension increased significantly with gluteal taping (p < 0.05) for both walking speeds at late stance phase of walk compared to sham taping and control. The mean absolute difference between gluteal and control conditions for self-selected velocity was 14.2 degrees (95% CI 8.6 to 19.8) whereas the difference between sham and control conditions was 2.0 degrees (95% CI –2.0 to 6.0). Also, for both speeds, step length on the unaffected side increased significantly with gluteal taping compared with either the control or placebo” conditions. 

link to full text: http://www.sciencedirect.com/science/article/pii/S0004951406700629

Aust J Physiother. 2006;52(1):53-6.Gluteal taping improves hip extension during stance phase of walking following stroke.Kilbreath SL, Perkins S, Crosbie J, McConnell J.

Gait and the lower visual field.

Gait and the eyes. We forget about the eyes. If you have vision issues, your gait may change.
Gaze during adaptive gait involving obstacle crossing is typically directed two or more steps ahead where as visual information of the “in the moment” swinging lower-limb and its relative position during the task is available in the lower visual field. This study determined exactly when visual information is utilised to control/update lead-limb swing trajectory during obstacle negotiation.
In this study, when the lower visual field was blocked out the foot-placement distance and toe-clearance became significantly increased, suggesting the brain overcorrecting for safety. A logical assumption. “These findings suggest that lower visual field input is typically used in an online manner to control/update final foot-placement, and that without such control, uncertainty regarding foot placement causes toe-clearance to be increased.”

http://www.ncbi.nlm.nih.gov/pubmed/22424759

“those with chronic neck pain demonstrated a narrower step width, a shorter step length and slower gait speed during walking with the head movements and at maximum speed” -  Uthaikhup et al. study:

Head movement and Gait Parameters:

By now you should have a good grasp of the global impact of gait and how it presents and translates in everything we do. It is how we move through this world, and everything we do, and everything that has happened to us, impacts our gait. And, our gait impacts things in turn, from our mental state to how we think and act.  

By now, if you have been with us here on The Gait Guys long enough, you know that with the tremendous proprioceptive impact of the system from the cervical spine, that neck pain can influence sensorimotor function and thus motor function. However, little is known about the effects of head movement and walking speed on gait characteristics in patients with neck pain.

From the Uthaikhup et al. study:

Patient sample:  20 women aged between 18 and 59 years with chronic neck pain (>3 months) and 20 healthy controls of similar age, weight and height

Indexes used: Neck Disability Index and Visual Analogue Pain Scale.

“The experiment consisted of two walking sessions. The first session included walking with head straight, head up-down, and head turns from side to side. The second session included walking at comfortable and maximum speeds. Each trial was performed twice. Gait parameters measured using GAITRite walkway system were step length, stride length, step time, stride time, step width, cadence and gait speed.”

According to this study, the clients with chronic neck pain showed several changes in how they implemented their gait. They displayed step width narrowing, a reduction in step length and speed of gait, and even an overall reduction in gait speed when neck movements were induced or encouraged or when there was pain..

As Uthaikhup et al. summarized, “The results suggest that patients with chronic neck pain have gait disturbances. This supports the notion that assessment of gait should be addressed in patients with persistent neck pain.”

You have to know your gait norms to understand abnormals. We have written about other parameters that affect gait speed, step length and width here on the blog. Here is one more parameter for you to store in your noggin. It is all connected. So, when you goto your gait analysis guru, ask them if they are going to clinically assess your painful neck as part of the gait analysis (be prepared for the “deer in the headlights” look).

Dr. Shawn Allen, one of the gait guys

Reference:

Man Ther. 2014 Apr;19(2):137-41. doi: 10.1016/j.math.2013.09.004. Epub 2013 Sep 27.The effects of head movement and walking speed on gait parameters in patients with chronic neck pain. Uthaikhup S, Sunkarat S, Khamsaen K, Meeyan K, Treleaven J.

Does slowing gait increase gait stability ?

As this study suggests, it has been difficult to find studies that establish a clear connection between gait stability and gait speed. One can easily assume that slowing down increases stability, we do it on slippery surfaces, we do it when a joint is painful, even the elderly do it naturally everyday. Walking speed, step length, step frequency, step width, local dynamic stability , and margins of stability were measured in this study below. It was found that the subjects did not change walking speed in response to the balance perturbations rather they made shorter, faster, and wider steps with increasing perturbation intensity. They became locally less stable in response to the perturbations but increased their margins of stability in medio-lateral and backward direction. 

So what did they conclude ?  Here are their words,“In conclusion, not a lower walking speed, but a combination of decreased step length and increased step frequency and step width seems to be the strategy of choice to cope with medio-lateral balance perturbations, which increases Margins of Stability (MoS) and thus decreases the risk of falling.”

It is my assumption, and this just seems logical, that if the perturbations were to continue constantly, that one would slow the gait speed to reduce the need for these shorter, faster and wider steps. 

Dr. Shawn Allen

http://www.ncbi.nlm.nih.gov/pubmed/22464635

Gait Posture. 2012 Jun;36(2):260-4. doi: 10.1016/j.gaitpost.2012.03.005. Epub 2012 Mar 29.Speeding up or slowing down?: Gait adaptations to preserve gait stability in response to balance perturbations.Hak L¹, Houdijk H, Steenbrink F, Mert A, van der Wurff P, Beek PJ, van Dieën JH.

Your gait and peripheral vision: Part 2. There is more to it than what you do/don’t see.

Written by Dr. Shawn Allen

Yesterday we did a blog post on the loss of peripheral vision from drooping eye lids leading to the necessity (not vanity based) of a minor surgical procedure called a blepharoplasty.  Here was that blog post (link), it had some important research based points you need to know.

Vision is typically the predominant sensory system used for guiding locomotion. Online visual control is critical for adjusting lower limb trajectory and ensuring proper foot placement, including optimal limb/foot crossing velocity, optimal trail-foot horizontal distance and lead-toe clearance. Research suggests that peripheral visual cues play a large role in this online gait control. 1

We have discussed many of these issues, the conscious and subconscious importance of vision on human gait, in many of our blog posts over time.  Namely, blog posts on dual-tasking attention, negotiating stairs, and even in tandem walking holding hands. These all require a degree of peripheral vision function otherwise gait problems, including falls, rise on the risk list.

According to Timmis and Buckley (2), “although gaze during adaptive gait involving obstacle crossing is typically directed two or more steps ahead, visual information of the swinging lower-limb and its relative position in the environment (termed visual exproprioception) is available in the lower visual field (lvf).”  Their study determined exactly when lvf exproprioceptive information is utilized to control/update lead-limb swing trajectory during obstacle negotiation. 

Their study determined that “when (the) lower visual field (lvf) was occluded, foot-placement distance and toe-clearance became significantly increased; which is consistent with previous work that likewise used continuous lvf occlusion”. Their findings suggest that “ lvf (exproprioceptive) input is typically used in an online manner to control/update final foot-placement, and that without such control, uncertainty regarding foot placement causes toe-clearance to be increased. Also that lvf input is not normally exploited in an online manner to update toe-clearance during crossing: which is contrary to what previous research has suggested.” 2

Elliot and Buckley (3) showed the importance of peripheral visual cues in the control of minimum-foot-clearance during overground locomotion. In their study, 

From their abstract: “eleven subjects walked at their natural speed whilst wearing goggles providing four different visual conditions: upper occlusion, lower occlusion, circumferential-peripheral occlusion and full vision. Results showed that under circumferential-peripheral occlusion, subjects were more cautious and increased minimum-foot-clearance and decreased walking speed and step length. The minimum-foot-clearance increase can be interpreted as a motor control strategy aiming to safely clear the ground when online visual exproprioceptive cues from the body are not available. The lack of minimum-foot-clearance increase in lower occlusion suggests that the view of a clear pathway from beyond two steps combined with visual exproprioception and optic flow in the upper field were adequate to guide gait. A suggested accompanying safety strategy of reducing the amount of variability of minimum-foot-clearance under circumferential-peripheral occlusion conditions was not found, likely due to the lack of online visual exproprioceptive cues provided by the peripheral visual field for fine-tuning foot trajectory.”

These appear to be important studies on the effects of vision and peripheral vision and proprioceptive cues.  How we move our bodies depends much on visual cues, the ones we know we see, and the ones we are unaware that we “see”. Take this to the next level, imagine how the blind must adapt to gait without these cues. That is gait topic we will save for another time.

So, the gait analysis you are doing with your runners, your athletes, your clients takes into consideration their vision right ? Hmmmm, some how we just know that many gait gurus just sat back in their chairs and let out a long exhale. We go even more rogue in podcast 95 when we discuss head tilt and the vestibular system, we know that one is almost always overlooked. Another long exhale we presume.

Shawn Allen … .  one of the gait guys

References:

1. Exerc Sport Sci Rev. 2008 Jul;36(3):145-51. doi: 10.1097/JES.0b013e31817bff72.Role of peripheral visual cues in online visual guidance of locomotion. Marigold DS¹.

2.Gait Posture. 2012 May;36(1):160-2. doi: 10.1016/j.gaitpost.2012.02.008. Epub 2012 Mar 17.Obstacle crossing during locomotion: visual exproprioceptive information is used in an online mode to update foot placement before the obstacle but not swing trajectory over it.Timmis MA¹, Buckley JG.

3. Gait Posture. 2009 Oct;30(3):370-4. doi: 10.1016/j.gaitpost.2009.06.011. Epub 2009 Jul 22.Peripheral visual cues affect minimum-foot-clearance during overground locomotion.Graci V¹, Elliott DB, Buckley JG.

Texting and Walking.  Your gait will change when you are texting on your phone.

You are going to want to put away your cell phone after you read this, or at least hide your parent’s phones. *(the video link attached here has likely been blocked by ABC News, you should see a forwarded link to their youtube feed. If not,

here it is

.  So you think you are a multi-tasker do you ?  Do you know how much cerebral cortex real estate is necessary to walk or drive and text ? Just try texting while walking for 5 seconds in an unfamiliar environment and see what happens.  Dual tasking is difficult especially when one task is cognitive and the other is spacial and motor. At some point something has to give, especially if you are on the edge of tapping out the executive function centers in the brain because of early disease or age related mental decline.  This has never been more prevalent than in the elderly and the number of mounting studies proving that dual attention tasks lead to a dramatic increase in age related fall injuries.  If you look into the literature the fall rate increases from anywhere from 11 to 50%, these are strong numbers correlating falls and dual attention tasking in the elderly.  Certainly the numbers are worse in the frail and gait challenged and fewer in healthier elderly folks, but the correlation seems to be strong particularly when there are even early signs of frontal cortex demise. We have talked about this on several recent podcasts

(check out podcasts 80-85)

and this has been rooted even further from one of our neurology mentors, Dr. Ted Carrick.   Recently in the Journal of Applied Biomechanics, Parr and associated took 30 young able bodied healthy individuals with experience texting on cellular phones. The study used an 11-camera optical motion capture system on a 8m obstacle-free floor. 

The study showed a reduction in gait velocity in addition to significant changes in spatial and temporal parameters, notably, step width, while the double support phase of the gait cycle increased.  Furthermore, and equally disturbing, toe clearance decreased but luckily step length and cadence decreased. 

Thus, it appears that the attention draining texting task generally forced the brain to slow the gait, reduce step length while improving stability via increasing step width and double support phase of gait, keep in mind that these are young healthy experienced individuals with no early cognitive challenges. 

This is not the case in aging adults, or in adults with factors that have either challenged gait stability (degrees of impaired balance, vision, vestibular, proprioception etc) or challenged frontal cortex function where that functionality of the brain is already nearing its tipping point for adequate function.  Sadly, these are all factors in the aging adult and they are why falls are increased and riskier for the elderly. Essentially, what the studies are showing is that dual tasking creates a distraction that can amplify any sensory-motor challenges in the system.  Mind you, there are studies that show that if the dual task is remedial such as talking while walking the effects are more muted, however in those who are at the tipping point capacity of mental executive function, mere talking (cognitive linguistic engagement), can also tip the system into deciding whether to focus on the gait or the talk but not both adequately.  Something will have to give in these folks, safe competent dual tasking is beyond the ability of their system.  As we have eluded to here, there are many factors and variables that can challenge the system. Visual challenges such as low light vision problems or depth perception challenges can act similarly on the system to dual tasking attempts and thus magnify fall risk. What about sensory challenges from a spinal stenosis or peripheral neuropathy such as in advancing diabetes?  Balance and vestibular challenges, let alone factors such as unfamiliar environments (perhaps magnified by vision challenges) as precursors are a foregone conclusion to increase fall risk in anyone let alone the elderly. By this point in this article it should be a given that texting while doing anything else is a dual tasking brain challenge that could lead to a fall, an embarrassing spill into the public pool or into a fountain at the mall let alone driving off a cliff or into a crowd of people.  But are all of these unfortunate people showing signs of frontal cortex/executive function impairment? Perhaps not, especially if they are healthy.  One has to keep in mind that texting is a high demanding cognitive attention task, even though we think nothing of it as a healthy adult. Think about it, one has to engage a separate screen other than the environment they are trying to walk through. Additionally, one has to think about what they are trying to text, engage a seperate motor program to type, then there is spelling, choosing text recipients, sending the message, watching and listening for a response, and the list goes on meanwhile the person is still trying to run the gait subprograms.  We take it for granted but texting is highly engaging and adding walking can tip the system into a challenge or failure if we are in a crowd, unfamiliar environment, low light etc.   So if you have ever wondered why elderly people trip and fall in even the most benign environments, it is likely a compounded result of challenges to situation and spatial awareness and working memory with many possible factor challenges. Again, things like poor lighting, vision limitations, unfamiliar environment, vestibular limitations, numbness in the feet, talking or even if they are simply carrying the afternoon tea to the sun room these things all are dual tasking and some require higher demands from the executive function brain centers.   Any factor(s) which tax the already-reducing executive function centers in the elderly subtract from the most basic elements required for upright posture and gait.  If dual-tasking can impair healthy young individuals, the elderly are a forgone conclusion to have magnified risks.   There can be a plus to all of this however. If the goal were to only reduce falls and fall risks in the elderly, an astute clinician can work this to their favor and do gait challenges and retraining in the office environment while safely stacking dual task challenges to expand and restore some executive function capabilities.  We are never too old to learn and lay down improved motor and cognitive patterns. So, use this information to your advantage to improve function instead of delivering it as a dark cloud to hang over your clients, whether they are elderly or neurologically challenged.  In summary, put down the darn phone, trust us, that text can wait.  Rather, enjoy the sunshine, the smiling faces, the trees.  If you are driving or walking, dump the phone and pay attention to traffic and your environment. Stop and wave to a friend. Teach your kids about this texting problem, they are likely already oblivious to many risks in the world, and this one likely hasn’t crossed their mind either. At the very least, help the elderly lady or man cross the street. By now you should understand all that they are consciously and subconsciously trying to calculate to negotiate the street crossing. Their declining executive function is often a mental feat all on its own, but having to actually add the physical act of walking (which is likely already showing aspects of age related biomechanical decline) might just be their tipping point leading to a fall.  So offer your arm, a warm smile, and think everything of it, because someday it will be you at that street corner with sweaty palms and great fear.  

Dr. Shawn Allen, one of the gait guys

References : 1. 

Eur J Neurol.

 2009 Jul;16(7):786-95. doi: 10.1111/j.1468-1331.2009.02612.x. Epub 2009 Mar 31. Stops walking when talking: a predictor of falls in older adults?

Beauchet O

1, 

Annweiler C

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Dubost V

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Allali G

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Kressig RW

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Bridenbaugh S

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Berrut G

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Assal F

, 

Herrmann FR

. 2. 

J Appl Biomech.

 2014 Dec;30(6):685-8. doi: 10.1123/jab.2014-0017. Epub 2014 Jul 9. Cellular Phone Texting Impairs Gait in Able-bodied Young Adults. 

Parr ND

1, 

Hass CJ

, 

Tillman MD

. 3. 

Gait Posture.

 2014 Aug 20. pii: S0966-6362(14)00671-7. doi: 10.1016/j.gaitpost.2014.08.007. [Epub ahead of print]  Texting and walking: effects of environmental setting and task prioritization on dual task interference in healthy young adults. Plumer, Apple, Dowd, Keith. 4. 

Gait Posture.

 2012 Apr;35(4):688-90. doi: 10.1016/j.gaitpost.2011.12.005. Epub 2012 Jan 5.  Cell Phones change the way we walk.  Lamberg, Muratori 5. 

Int J Speech Lang Pathol.

 2010 Oct;12(5):455-9. doi: 10.3109/17549507.2010.486446.  Talking while walking: Cognitive loading and injurious falls in Parkinson;s disease. 

LaPointe LL

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Stierwalt JA

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Maitland CG

.

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 we continue, you should recall that there is a brief double limb support phase in walking gait, that which is absent in running gait. Also, we 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 us 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).  For example, when right ankle rocker (dorsiflexion) is impaired, early heel departure will occur and hip extension will be limited. An alteration in right glute function will most likely follow.  One could theorize that the left step length (the length of measure from right heel strike through to left heel strike) would thus be shortened. This would cause a premature load onto the left limb, and could very well force the left frontal plane to be more engaged than is desirable. This could lead to left core and hip frontal plane weakness and compensation patterns to be generated (ie. right arm abduction. One can see all of these components in the photo above, and in this case here). It could also lead to a pelvic distortion pattern which would further throw off the anti-phasic nature of symmetrical and efficient gait.  To complicate the cyclical scenario, the time usually used to move sagittally will be partially used to move into, and back out of, the left frontal plane. This will necessitate some abbreviations in the left stance phase timely mechanical events. Some biomechanical events will have to be abbreviated or sped through and then the right limb will have to adapt to those changes. These are simple gait problems we have talked about over and over again here on the gait guys blog. (Search “arm swing” on our blog and you will find 45 articles around this topic.) These compensation patterns will include expressed weaknesses in various parts of the human frame as part of the pattern, and merely fixing those weaknesses does not address the right ankle rocker problem. Fixing said weaknesses merely encourages the brain to possibly continue to perpetuate necessary tightnesses in other muscles and engrain the compensations (challenges to mobility and stability) further or more complexly.  It is easy to find something weak, it takes a sharp brain to find the sometimes silent sparking event. Are you able to find the problem in this never ending loop of compensations and find a way to unwrinkle the system one logical piece at a time, or will you just chose to strengthen the wrinkled system and hope that the new strength on top of the compensations is adequate for you our your client ? One should not be forever sentenced to daily or weekly rehabilitative sessions/ homework to negate and alleviate symptoms, this is a far more durable machine than that. Fix the problem.

Now, lets add another wrinkle to the system.  What if there were problems before any injuries ?  Meaning, what if there were problems during the timely maturation and suppression of the primitive reflexes ? Or problems in the timely appearance or maturation of postural reflexes? A problem in these areas may very well result in a central or peripheral nervous system malfunction and a representation of such in one’s movement and gait.  That is a larger discussion for another time.

There is a reason that in our practices we often assess and treat contralateral upper and lower limbs as well as to address remnants from old injuries whether they are symptomatic or not. This is a really tough puzzle and game you are playing. For example, when there is insufficient hip internal rotation unilaterally you can regain some of the loss through increased foot pronation unilaterally, but at a consequence to both the local and global pictures.  Remember, most of the time you are trying to walk in a straight line from A to B and if the parts are not symmetrical you have many options to compensate. It is not as simple as telling your athlete to swing one arm more, or to stop pulling it across their body; they need to do those things, it is called a “compensation”. It is often not as simple as finding an impaired Rolling Pattern and driving it back to symmetry, in doing so, you may have just added strength and skill to a compensation.  Merely addressing things locally can be a crime.  If you are seeing an arm swing change, you would be foolish not to look at the opposite lower limb and foot at the very least, and of course assess spinal rotation, lateral flexion and hinging as well as core mobility and stability.  For your neuro nerds, remember the receptors from the central spine and core fire into the midline vermis of the cerebellum (one of the oldest parts of our brain, called the paleo cerebellum); and these pathways, along with other cerebellar efferents, fire our axial extensor muscles that keep us upright in the gravitational plane and provide balance or homeostasis.  So, those need assessed and addressed as well.  

Or, if this is too much thinking for you, … you can just train harder and get stronger . .  . in all your compensation patterns, after all, it is easier than figuring out why and how that right ankle started the whole mess, if in fact that is even the first piece of the puzzle.

Welcome to the matrix.

shawn and ivo, the gait guys

The power to bend bones.

What have we here? Hmmm. This little girl was brought in by her mother because of intermittent knee pain and “collapsing” of the knees while walking, for no apparent reason.

The ankle dorsi flexion (or ankle rocker; see last 2 pictures; we are fully dorsiflexing the ankles)  needs to occur somewhere, how about the knees? Or in this case, the tibia. Wow!

You are looking at a 4 year year with a condition called genu (and tibial) recurvatum. Genu recurvatum is operationally defined as knee hyperextension greater than 5 degrees. The knee is hyperextended, and in this case, the tibia is literally “bent backward”. Look at the 2 pictures of her tibia.

Generally speaking, the tibial plateau usually has a slight posterior inclination (as it does in this case; look carefully at the 1st picture) causing the knee to flex slightly when standing. Sometimes, if it is parallel with the ground and the center of gravity is forward of the knees, the knee will hyperextend (or in this case, the tibia will bend) to compensate.

In this particular case, the tibia has compensated more, rather than the knee itself. The knee joint is stable and there is no ligamentous laxity as of yet. She does not have a neurological disorder, neuromuscular disease or connective tissue disorder. She has congenitally tight calves.

As you can imagine, her step length is abbreviated and ankle rocker is impaired.

So what did we tell her Mom?

• keep her barefoot as much as possible (incidentally, she loves to be barefoot most of the time, gee, go figure!)
• have her walk on her heels (she’s a kid, make a game of it)
• showed her how to do calf stretches
• balance on 1 leg with her eyes open and closed
• keep her out of backless shoes (like the clogs she came in with)
• keep her out of flip flops and sandals where she would have to “scrunch” her toes to keep them on.
• follow back in 3 months to reassess

There you have it. Next time you don’t think Wolff’s (or Davis’s) law* is real, think about this case. Want to know more? Consider taking our National Shoe Fit Program, available by clicking here.

The Gait Guys. Making you gait IQ higher with each post.

*Wolff’s law: Bone will be deposited in areas of stress and removed in areas of strain. or put another way: bone in a healthy person or animal will adapt to the loads under which it is placed

Davis’s law: soft tissue will adapt to the loads that are placed on it

Do they not only look dumb, but reduce your IQ to your waist size?

Can sagging pants lead to cognitive decline? 

There are a number of papers being written about gait changes (step length, frequency, speed)  being indicative of cognitive decline (see here and here for 2 of them).

Wearing sagging, baggy pants has many associated issues (see here for our recent post on that). Can the reverse be true? Can creating a smaller step length cause cognitive decline?

Neurologically, we know that the cerebellum is involved with learning. Balance and coordination tasks improve learning. Yes, it is better to have have your kids banging and climbing on the TV, rather than being passive and watching it.  This is probably due to muscle and joint mechanoreceptors being activated, and that information traveling northward in the spinocerebellr tracts which feed to the flocculo nodular lobe and cerebellar hemispheres. Here they interact with converging input from all the other systems (vision, hearing, and probably smell), as well as descending motor information from your motor cortex. They are processed and then redirected to the areas where they came from, as well as to systems which project that information to many places, including, you guessed it, your temporal lobe (memory), parietal lobe (special integration and discrimination) and frontal lobe (personality and motor activity).

So, what happens when you slow or decrease information to the cerebellum? What happens if we don’t use neurons? They degenerate, or are remodeled into something else as the pathways slowly grow over and are replaced by other information your brain sees as more important.

Could decreasing your step length, altering and/or diminishing proprioception affect cerebellar output? Yes. Could this affect your ability to learn and remember? Yes. Could this lead to cognitive decline? Conceivably…

We think you know  where we stand on this. Think before you sag…while you still can

The Gait Guys.  Definitely NOT saggy : )