Turning: Connecting the kinetic chain

Look at the photo, which way am I turning my head ? How hard am I turning ? Perhaps I am turning hard through my neck and thoracic spine to look over my shoulder.  The point is, you can see it in my feet and if you know your biomechanics you should easily know which way I am turned.

 It should be simple and clear that I am turning my neck and thoracic spine strongly to the left.  The left rotation has forced me to find stability over the lateral left foot while driving the rotation with the right foot.  Left foot had to supinate, right had to pronate. No rocket science here.
Earlier in the week I posted a brief discussion on the neck and proprioception and the upper and lower limb. I caught some questions on challenging the strength of the neurological linkages to the lower limb, so I promised a simple picture to solidify my point.
Where is what i wrote earlier this week.
"From the study: "Limb proprioception is an awareness by the central nervous system (CNS) of the location of a limb in three-dimensional space and is essential for movement and postural control. The CNS uses the position of the head and neck when interpreting the position of the upper limb, and altered input from neck muscles may affect the sensory inputs to the CNS and consequently may impair the awareness of upper limb joint position."

We say it is not just the upper limb however, the neck and head posture is used in interpreting the position of the lower limb as well. And similarly altered head/neck muscle input can impair awareness of the lower limb posture as well. Think about it, we are trying to stay upright in the gravitational plane while keeping the eyes and vestibular centers on the horizon. Gait is nothing more than a single leg balancing act repeated over and over. Faulty info on where our center of pressure is from a visual or vestibular aspect will alter where we put our foot in space. Just look at how many neurologic diseases end up with a wider based gait, because our proprioceptive centers no longer trust our base of support. It is all connected."

Exp Brain Res. 2015 May;233(5):1663-75. doi: 10.1007/s00221-015-4240-x. Epub 2015 Mar 13.

Neck muscle fatigue alters upper limb proprioception.

Zabihhosseinian M1, Holmes MW, Murphy B.
 

As in this study, and putting it together with my photo and discussion at the start here today, limb proprioception is an awareness by the CNS of the location of the limb and is essential for proper movement and postural control. If I had rotated to the left and had my CNS not known where the foot was in space and in relation to the rest of my body, I may have fallen over to the left. Instead, my CNS sensed the weight shift to the left from the neck and torso rotation, and moved my foot weight bearing into supination (affording a slightly greater lateral weight bearing on the foot) to accommodate the shift in my center of pressure and mass laterally.  So, the CNS used the position of the head and neck, and the weight shift, in interpreting the appropriate positioning of the lower limbs. Sometimes moving the foot into supination to accommodate the lateral load is not enough, and we need to actually step laterally to maintain upright.  Altered input from my neck muscles might affect the sensory inputs to the CNS and consequently may impair the awareness of my limb joint positioning in space. This happens often in vestibular challenged clients and in client of aging decline where the system is losing proprioception. If we do not know where a body part is in space, we don't know how to use it or how to load it (think about chronic ankle sprains).

As i said earlier this week, think about it, we are trying to stay upright in the gravitational plane while keeping the eyes and vestibular centers on the horizon. Gait is nothing more than a single leg balancing act repeated over and over. Faulty info on where our center of pressure is from a visual or vestibular aspect will alter where we put our foot in space. Just look at how many neurologic diseases end up with a wider based gait, because our proprioceptive centers no longer trust our base of support. It is all connected.

Think about how amazing this system is when it works right, we can run on a track leaning into the curve, we can ride a bike and lean into turns, we can run forward and yet turn to look behind us, all without falling over -- thanks to our CNS and joint proprioception.

Dr. Shawn Allen, the other gait guy

Children: Postural control of balance

From the study:

“From these indexes it was established that the postural capacity needed just to control balance with the leg muscles was not attained before 4-5 years of independent walking, i.e., at about 5-6 years of age.” -Breniere

reference link:

Exp Brain Res. 1998 Aug;121(3):255-62.Development of postural control of gravity forces in children during the first 5 years of walking.Brenière Y¹, Bril B.

http://www.ncbi.nlm.nih.gov/pubmed/9746131/

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.

“I keep walking into doorframes,” : A visual aspect of problematic gait you likely have not considered.

Written by Dr. Shawn Allen

Recently i had an elderly client come in to see me, we were working on some arthritic knee problems post-total knee arthroplasty. He mentioned to me that he recently had eye surgery because he was having some gait difficulties. My brain immediately when into age related gait decline, you know, balance kind of stuff.  He mentioned that he was banging into door frames because he was not clearing the sides of the door frames and was also banging up his knees, ankles, thighs and toes on many other things.  He said he had been getting anxious about his gait and thought he might be experiencing some kind of neurologic gait problem. He wasn’t trusting his gait, he feared leaving his house. He happened to mention it to his eye doctor a few months ago and here is what he told him .  

“Your upper eye lids are drooping so much that they are obliterating your peripheral vision. You can’t avoid banging into things that you cannot see. Your peripheral vision is imperative for normal safe gait.”

Drooping eyelids are an inevitable effect of getting older, but the sagging eyelids can impair peripheral vision and magnify gait risks. The procedure known as a blepharoplasty is a simple procedure performed on the upper eyelid when the lid drops down and creates a lateral blind or fold blocking out the lateral eye fields. When looking to the extremes of lateral gaze or depending on peripheral vision this fold blocks the lateral field on the affected eye while the bridge of the nose blocks the same lateral field of the other eye. Effectively, the lateral gaze and peripheral vision becomes progressively narrowed. 

Watch the gait of your elderly clients. Observe how they move about your office, around furniture, tables, door frames. Ask if their gait is uncertain. Ask if they are running into things for no apparent reason.  Think about this next time you are walking in close proximity of the elderly, just because you see them in your peripheral vision, does not mean they can see you.  Remember, their balance and stability is likely not what yours is, it might not take much to knock them over for what appears to be little reason at all.

From the Graci study: 

“However, under CPO conditions (circumferential peripheral visual field occlusion), the doorframe led to a further reduction in crossing velocity and increase in trail-foot horizontal distance and lead-toe clearance, which may have been because of concerns about hitting the doorframe with the head and/or upper body.”

From their conclusions, “exteroceptive cues are provided by the central visual field and are used in a feed-forward manner to plan the gait adaptations required to safely negotiate an obstacle, whereas exproprioceptive information is provided by the peripheral visual field and used online to “fine tune” adaptive gait. The loss of the upper and lower peripheral visual fields together had a greater effect on adaptive gait compared with the loss of the lower visual field alone, likely because of the absence of lamellar flow visual cues used to control egomotion.”

Shawn Allen, one of the gait guys.

1. Optom Vis Sci. 2010 Jan;87(1):21-7. doi: 10.1097/OPX.0b013e3181c1d547.Utility of peripheral visual cues in planning and controlling adaptive gait.Graci V¹, Elliott DB, Buckley JG.

2. http://abcnews.go.com/blogs/health/2013/05/31/eye-lifts-fine-line-between-cosmetic-and-therapeutic/

Gait on slippery floors.

You seem to see a glossy wetness to the tile floor ahead of you in the supermarket. Is that just a really polished floor or is that water? Hey, it might be slippery, lets make some adaptive changes up there in the brain.
Postural and temporal gait adaptations, which affected ground reaction forces occur.
This study found that “statistically significant gait adaptations included reductions in stance duration (SD) and loading speed on the supporting foot, shorter normalized stride length (NSL), reduced foot-ramp angle and slower angular foot velocity at heel contact. As a result of these adaptations, anticipation of slippery surfaces led to significant changes in lower extremity joint moments, a reflection of overall muscle reactions.”
Significant gait changes occur when there is percieved risk of slipping, and in this study, “even though subjects were asked to walk as naturally as possible”.

Changes in gait when anticipating slippery floors.
Cham R, et al. Gait Posture. 2002.
http://www.ncbi.nlm.nih.gov/m/pubmed/11869910/

A Wobble in the System: The Gait Changes in Normopressure Hydrocephalus

Can you afford to miss this diagnosis ? 

Today, the gait changes in NPH are discussed because as with many neurologic disorders and diseases, subtle gait changes are the first signs. And, in this disorder, you have to catch the gait changes early on in order to give your client the greatest changes of full recovery.   Today we couple this blog post with a great video story of a missed case study of NPH.

Normopressure hydrocephalus (NPH) consists of the triad of :

1. gait disturbance
2. urinary incontinence
3. dementia or mental decline

In the most general terms, Normal pressure hydrocephalus (NPH), also referred to as symptomatic hydrocephalus, is caused by a decreased absorption of cerebrospinal fluid (CSF). The resultant increased intracranial pressure can cause ventriculomegaly.  In NPH patients, the pressure remains just slightly elevated, but enough to create pressure on the cortical tissues of the brain causing the symptoms above. The vagueness of this problem and its seemingly random symptoms is primarily why this disorder is often missed or misdiagnosed as dementia, Parkinson’s or Alzheimers disorders.

As discussed previously, many early neurological diseases and disorders softly present with early gait changes. And, as in NPH, gait changes may be the earliest symptom of the 3 mentioned earlier. One’s ability to know, observe and recognize abnormal gait patterns coupled with a good historical interview and physical exam can often tease out the earliest manifestation of NPH.

Here is what you need to know about the gait presentation in NPH:

The gait changes are often subtle and progress as NPH progresses because of the changes in the brains ventricular tissues eventually compromising the sensory-motor tracts.
Early gait changes, MILD, may show a cautious gait. Steps length and stride length may be slowed and shortened. The gait may begin to show signs of being deliberate and calculated, less fluid and free. The appearance of unsteadiness or balance challenges may prevail. Once simple environmental obstacles may now present as challenges, things like curbs, stairs, weaving between tables in restaurants or wide open spaces where there is nothing to grasp onto for stability. Weakness and tiredness of the legs may also be part of the complaint, although examination discloses no paresis or ataxia. (Ropper)  A walking aid such as a cane may add comfort but often appears to be rarely used.

As the gait changes progress into the more MODERATE to ADVANCED, the walking aids used often progress into quad walkers.  Wheelchairs are needed in more difficult places or when fatigue is growing factor.  As the gait challenges progress, the careful observer will note a more obvious reduction in step and stride length, a head down posture, less dual tasking engagement during gait execution, slowed walking speed, reduced foot-floor clearance, shuffling gait (keeping the feet more engaged to the ground, this can be a Parkinsonian-type gait mis-read, there will be no tremor or rigidity), searches for stable external cues (reaching for railings, a kind arm or hand, touching walls etc), widening of the feet (broad based stance), and fears of falling backward.

In the most ADVANCED gait impairments, the fear of falling can become too great. There may even be an inability to engage sit-stand-walk motor patterns and the fatigue of the limbs may be too advanced to even stand let along walk. This stage is referred to as Hydrocephalic astasia-abasia (Ropper).  

Normopressure Hydrocephalus is a serious issue if left unrecognized and untreated. Here is yet another reason why you must be familiar with this problem:

“Patients with dementia who are confined to a nursing home and may have undiagnosed NPH can possibly become independent again once treated. So far only one study was able to evaluate the prevalence of NPH, both diagnosed and undiagnosed, among residents of assisted-living facilities, showing a prevalence in 9 to 14% of the residents.” - Marmarou

One’s lack of awareness and knowledge, are one’s greatest enemies. If you don’t know something exists, because you’ve never studied or learned it, how can you be aware of it ? If you’re not spending enough time examining a client, you might be unaware of an issue even though you may be knowledgeable about the issue. One must have both awareness and knowledge. One must also be aware that compensations are the way of the body. What you see is not your client’s problem. It is their strategy to cope.

NPH must be diagnosed early on since a delay in reducing the pressure on the cortical tissues can lead to permanency of disease and dysfunction.  According to Poca there can be a wide range of successes and failures in symptom remediation, but there is clearly a time dependency on early diagnosis. Thus, clearly recognizing any early gait changes and behaviors prior to advancing incontinence and mental decline is paramount.

Bonus: here is a little bonus tidbit for my fellow neuro gait friends. 

Stolze (7) study conclusion: “The gait pattern in normal pressure hydrocephalus is clearly distinguishable from the gait of Parkinson’s disease. As well as the basal ganglia output connections, other pathways and structures most likely in the frontal lobes are responsible for the gait pattern and especially the disturbed dynamic equilibrium in normal pressure hydrocephalus. Hypokinesia and its responsiveness to external cues in both diseases are assumed to be an expression of a disturbed motor planning.”

Dr. Shawn Allen, … one of “the gait guys”

Some of the above was inspired and summarized by this great article, from the Boston Globe.  

References:

1. Marmarou, Anthony; Young, Harold F.; Aygok, Gunes A. (1 April 2007). “Estimated incidence of normal-pressure hydrocephalus and shunt outcome in patients residing in assisted-living and extended-care facilities”. Neurosurgical FOCUS 22 (4): 1–8.

2. Ropper, A.H. & Samuels, M.A. (2009). Adams and Victor’s Principles of Neurology (9th edition). New York, NY: McGraw-Hill Medical.

3. Poca, Maria A.; Mataró, Maria; Matarín, Maria Del Mar; Arikan, Fuat; Junqué, Carmen; Sahuquillo, Juan (1 May 2004). “Is the placement of shunts in patients with idiopathic normal pressure hydrocephalus worth the risk? Results of a study based on continuous monitoring of intracranial pressure”. Journal of Neurosurgery 100 (5): 855–866.

4. Am J Phys Med Rehabil. 2008 Jan;87(1):39-45.
Objective assessment of gait in normal-pressure hydrocephalus.
Williams MA1, Thomas G, de Lateur B, Imteyaz H, Rose JG, Shore WS, Kharkar S, Rigamonti D.

5. Clin Neurophysiol. 2000 Sep;111(9):1678-86.
Gait analysis in idiopathic normal pressure hydrocephalus–which parameters respond to the CSF tap test?
Stolze H1, Kuhtz-Buschbeck JP, Drücke H, Jöhnk K, Diercks C, Palmié S, Mehdorn HM, Illert M, Deuschl G.

6.Rev Neurol (Paris). 2001 Nov;157(11 Pt 1):1416-9.
[Postural and locomotor evaluation of normal pressure hydrocephalus: a case report]. Mesure S1, Donnet A, Azulay JP, Pouget J, Grisoli F.

7.J Neurol Neurosurg Psychiatry. 2001 Mar;70(3):289-97.
Comparative analysis of the gait disorder of normal pressure hydrocephalus and Parkinson’s disease.
Stolze H1, Kuhtz-Buschbeck JP, Drücke H, Jöhnk K, Illert M, Deuschl G.

Gait: sometimes it is about the ear (sort of).

We have talked on several occasions about the aging population and the high morbidity and mortality rates with falls in this population. We have discussed the eyes, dual tasking, changes in environment and many other factors that play seamlessly into normal gait, things we all take for granted. But the aging population has yet another challenge, declining function of the vestibular apparatus. We often hear about balance, and we tend to treat it without truly thinking that this is a integration of the eyes, ears and proprioceptive systems together. If you have clients with multiple falls for unknown reasons, it is time to send them for a check up of the mechanical components of the vestibular system (and visual check up as well) you should be able to do the functional vestibular assessments in your office for the most part.

Recent studies are showing significant declines in semicircular canal function in each of the canal planes as well as otolith function within the aging population. “These findings suggest that age-related slowing of gait speed is in part mediated by the decreased magnitude of saccular response associated with age. ” -Ferrucci study

While the Agrawal study suggested “an overall decline in semicircular canal as well as otolith function associated with aging, although the magnitude of impairment was greater for the semicircular canals than the otoliths in this elderly population. A better understanding of the specific vestibular deficits that occur with aging can inform the development of rational screening, vestibular rehabilitation, and fall risk reduction strategies in older individuals.”

Dr. Shawn Allen, the gait guys

References:

Otol Neurotol. 2015 Jan 7. [Epub ahead of print]
Association Between Saccular Function and Gait Speed: Data From the Baltimore Longitudinal Study of Aging. Layman AJ1, Li C, Simonsick E, Ferrucci L, Carey JP, Agrawal Y.

Otol Neurotol. 2012 Jul;33(5):832-9. doi: 10.1097/MAO.0b013e3182545061.
Decline in semicircular canal and otolith function with age.
Agrawal Y1, Zuniga MG, Davalos-Bichara M, Schubert MC, Walston JD, Hughes J, Carey JP.

Foot Clearance: We don't think about it until we are face down in the mud, and we have all been there.

How many times have you tripped over something so small and insignificant you can barely believe it ? We have all tripped over a small elevation in a cracked sidewalk or a curled up rug corner.  But sometimes we look back and there is no evidence of a culprit, not even a Hobbit or an elf.  How can this happen ?

Minimum foot clearance (MFC) is defined as the minimum vertical distance between the lowest point of the foot of the swing leg and the walking surface during the swing phase of the gait cycle. In other simpler words, the minimum height all parts of the foot need to clear the ground to progress through the swing phase of the limb without contacting the ground. One could justify that getting as close to this minimal amount without catching the foot is most mechanically advantageous.  But, how close to vulnerability are you willing to get ? And as you age, do you even want to enter the danger zone ? Obviously, insufficient clearance is linked to tripping and falling, which is most concerning in the elderly. 

Trips or falls from insufficient foot clearance can be related to insufficient hallux and toe(s) dorsiflexion (extension), ankle dorsiflexion, knee flexion and/or hip flexion, failure to maintain ipsilateral pelvis neutral ( anterior/posterior pelvis posture shifting), even insufficient hip hike generated by the contralateral hip abductors, namely the gluteus medius in most people’s minds. It can also be from an obvious failed concerted effort of all of the above. Note that some of these biomechanical events are sagittal and some are frontal plane.  However, do not ever forget that the swing leg is moving through the axial plane, supported in part by the abdominal wall, starting from a posteriorly obliqued pelvis at swing initiation into an anteriorly obliqued position at terminal swing. We would be remiss as well if we did not ask the reader to consider the “inverted pendulum theory” effect of controlling the dynamically moving torso over the fixed stance phase leg (yes, we could have said “core stability” but that is so flippantly used these days that many lose appreciation for really what is happening dynamically in human locomotion).  If each component is even slightly insufficient, a summation can lead to failed foot clearance.  This is why a total body examination is necessary, every time, and its why the exclusive use of video gait analysis alone will fail every time in finding the culprit(s). 

When we examine people we all tend to look for biomechanical issues unless one grasps the greater global picture of how the body must work as a whole. When one trips we first tend to look for an external source as the cause such as a turned up rug or an object, but there are plentiful internal causes as well. For example, we have this blog post on people tripping on subway stairs.  In this case, there was a change in the perceptual height of the stairs because of a subconscious, learned and engaged sensory-motor behavior of prior steps upward.  However, do not discount direct, peripheral and lower fields of view vision changes or challenges when it comes to trips and falls. Do not forget to consider vestibular components, illumination and gait speed variables as well.  Even the most subtle change in the environment (transitions from tile to carpet, transitions from treadmill to ground walking etc) can cause a trip or fall if it is subtle enough to avoid detection, especially if one is skirting the edge of MFC (minimal foot clearance) already. And, remember this, gait has components of both anticipatory and reactive adjustments, any sensory-motor adaptive changes that impair the speed, calculation and timely integration of these adjustments can change gait behaviors. Sometimes even perceived fall or trip risk in a client can easily slip them into a shorter step/stride length to encourage less single leg stance phase and more double support phase gait. This occurs often in the elderly. This can be met with a reduced minimal foot clearance by design which in itself can increase risk, especially at the moment of transition from a larger step length to a shorter one. Understanding all age-related and non-age related effects on lower limb trajectory variables as described above and only help the clinician become more competent in gait analysis of your client and in understanding the critical variables that are challenging them. 

Many studies indicate that variability and consistency in a motor pattern such as those necessary for foot clearance are huge keys for predictable patterns and injury prevention, and in this case a predictor for trips and falls.  Barrett’s study concluded that “greater MFC variability was observed in older compared to younger adults and older fallers compared to older non-fallers in the majority of studies. Greater MFC variability may contribute to increased risk of trips and associated falls in older compared to young adults and older fallers compared to older non-fallers.”

Once again we outline our mission, to enlighten everyone into the complexities of gait and how gait is all encompassing.  There are so many variables to gait, many of which will never be noted, detected or reflected on a gait analysis and a camera.  Don’t be a minimalist when it comes to evaluating your client’s gait, simply using a treadmill, a camera and some elaborate computer software are not often going to cut the mustard when it really counts.  A knowledgeable and engaged brain are arguably your best gait analysis tools.  

Remember, what you see in someone’s gait is not their problem, it is their adaptive strategy(s).  That is all you are seeing on your camera and computer screen, compensations, not the source of the problem(s).

Shawn and Ivo

the gait guys

References (some of them): 

1. Gait Posture. 2010 Oct;32(4):429-35. doi: 10.1016/j.gaitpost.2010.07.010. Epub 2010 Aug 7.

A systematic review of the effect of ageing and falls history on minimum foot clearance characteristics during level walking. Barrett RS1, Mills PM, Begg RK.

2. Gait Posture. 2007 Feb;25(2):191-8. Epub 2006 May 4. Minimum foot clearance during walking: strategies for the minimisation of trip-related falls. Begg R1, Best R, Dell’Oro L, Taylor S.

3. Clin Biomech (Bristol, Avon). 2011 Nov;26(9):962-8. doi: 10.1016/j.clinbiomech.2011.05.013. Epub 2011 Jun 29. Ageing and limb dominance effects on foot-ground clearance during treadmill and overground walking. Nagano H1, Begg RK, Sparrow WA, Taylor S.

4. Acta Bioeng Biomech. 2014;16(1):3-9. Differences in gait pattern between the elderly and the young during level walking under low illumination. Choi JS, Kang DW, Shin YH, Tack GR.

Podcast 85: Texting & Walking, 2015 Shoe talk

Plus: Endurance training and the immune system, hamstring endurance, Ampla Fly shoe, 

Show sponsors:

www.newbalancechicago.com

A. Link to our server: 

http://traffic.libsyn.com/thegaitguys/pod_85f.mp3

Direct Download: 

http://thegaitguys.libsyn.com/podcast-85-texting-walking-2015-shoe-talk

Other Gait Guys stuff

B. iTunes link:

https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138

C. Gait Guys online /download store (National Shoe Fit Certification and more !) :

http://store.payloadz.com/results/results.aspx?m=80204

D. other web based Gait Guys lectures:

Monthly lectures at : www.onlinece.com   type in Dr. Waerlop or Dr. Allen,  ”Biomechanics”

Show notes:

Exercising Too Long Can Hurt Your Immune System
http://www.outsideonline.com/news-from-the-field/Exercising-for-Too-Long-Can-Hurt-Your-Immune-System.html

Future Shoe: New Ampla Fly Shoe Breaks The Mold
http://running.competitor.com/2014/11/video/nov-30-future-shoe-new-ampla-fly-shoe-breaks-mold_118688

How We Test Shoes
http://www.runnersworld.com/running-shoes/how-we-test-shoes?adbid=10152448718631987&adbpl=fb&adbpr=9815486986&cid=socSG_20141203_36589687

Three minutes of all-out intermittent exercise per week increases skeletal muscle oxidative capacity and improves cardiometabolic health
https://www.readbyqxmd.com/read/25365337/three-minutes-of-all-out-intermittent-exercise-per-week-increases-skeletal-muscle-oxidative-capacity-and-improves-cardiometabolic-health

http://www.ncbi.nlm.nih.gov/pubmed/21446352

http://www.ncbi.nlm.nih.gov/pubmed/21446353

 

Isolated Hamstrings Fatigue Alters Hip and Knee Joint Coordination During a Cutting Maneuver
http://journals.humankinetics.com/jab-in-press/jab-in-press/isolated-hamstrings-fatigue-alters-hip-and-knee-joint-coordination-during-a-cutting-maneuver

The Gait Guys talk about Cerebellar Afferents

http://youtu.be/tP-PvzB-fYM

Texting and Walking

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2535903/

 

 

Proprioceptive afferent inputs can control the timing and pattern of locomotion. When disease is present, or when injury has compromised the neuro-biomechanical linkages, slow postural responses can trump what timely responses are necessary to ensure for smooth locomotion.

 

When many people think of balance and locomotion, the cerebellum is often a top topic for it is important for movement control and plays a particularly crucial role. Thus, a most characteristic sign of cerebellar damage is walking ataxia. It is not known how the cerebellum normally contributes to walking, although recent work suggests that it plays a role in the generation of appropriate patterns of limb movements, dynamic regulation of balance, and adaptation of posture and locomotion through practice. (1)

Reflex pathways exist which regulate the timing of the transition from stance to swing, and control the magnitude of ongoing motoneuronal activity. During locomotion there is a closely regulated feedback from the various sensory receptors in the skin, joints, muscles, tendons, ligaments and other tissues, this is referred to as afferent feedback. When there is damage to these sensory “organs”, or the pathways into, or out of, the central nervous system locomotion becomes difficult.  We can see this in the video case above. This is a case of Chronic Inflammatory Demyelinating Polyradiculopathy (CIDP). It is an immunne-mediated inflammatory disorder of the peripheral nervous system whereby the myelin sheath of neurons is slowly eroded and as a result, the affected nerves and pathways fail to respond well rendering numbness, paresthesias, pain and progressive muscle weakness along with loss of deep tendon refexes. Obviously this will render locomotion fatiguing and difficult. Falls are not uncommon as you can see in the video.

 

Timing and coordination is everything in gait. When a portion of the system is compromised from injury or neurologic deficit, locomotion becomes strained.  There is an intricate balance between the extensor and flexor muscles.  We found this quote by Lam and Pearson particularly relevant to today’s discussion and video.

“Proprioceptive feedback from extensor muscles during the stance phase ensures that the leg does not go into swing when loaded and that the magnitude of extensor activity is adequate for support. Proprioceptive feedback from flexor muscles towards the end of the stance phase facilitates the initiation of the swing phase of walking. Evidence that muscle afferent feedback also contributes to the magnitude and duration of flexor activity during the swing phase has been demonstrated recently. The regulation of the magnitude and duration of extensor and flexor activity during locomotion is mediated by monosynaptic, disynaptic, and polysynaptic muscle afferent pathways in the spinal cord. In addition to allowing for rapid adaptation in motor output during walking, afferent feedback from muscle proprioceptors is also involved in longer-term adaptations in response to changes in the biomechanical or neuromuscular properties of the walking system.” (2)

Gait and any form of locomotion are highly complicated with many pieces necessary to achieve clean, smooth, coordinated motion.  Failure in only one piece of the puzzle can result in profound unhinging of the entire system because of the entangled nature of the feedback loops.  

Nothing dramatic today gang, just some thoughts that came to us after seeing this client and doing some reading to keep up on things.  We thought this would be a nice follow up to Monday’ blog post on proprioception.

Shawn and Ivo

the gait guys

References:

1. Neuroscientist. 2004 Jun;10(3):247-59.

Cerebellar control of balance and locomotion.

Morton SM1, Bastian AJ.

2. Adv Exp Med Biol. 2002;508:343-55.

The role of proprioceptive feedback in the regulation and adaptation of locomotor activity. Lam T1, Pearson KG.

According to the CDC, falls are the number one reason for death and injury among people age 65 and older. More than two million older people went to an emergency room in 2010 because of a fall.

From the article “The Science of Trips and Falls” (link)

“After a fall, older people often say they tripped or slipped. Researchers at Simon Fraser University, in Burnaby, British Columbia, wanted to observe what really happens. The team outfitted a long-term-care facility with video cameras and recorded residents going about their daily lives. They recorded 227 falls from 130 individuals over about three years. Tripping caused just 1 out of 5 of the incidents. The biggest reason for falling—accounting for 41% of the total—was due to incorrect weight shifting, like leaning over too far, says Stephen Robinovitch, a professor in the biomedical physiology and kinesiology and engineering science departments. Other, less frequent reasons for falling included loss of support with an external object, like a walker, or bumping into something.”

Using Tai Chi in the gait retraining process. Watch the attached video above.

This is particularly useful in reteaching weight transfer in the elderly or in the post operative hip, knee or foot clients. It is most useful in post operative total hip or total knee replacements. Note the slow loading responses which focus on effective weight transfer and loading as well as forcing safe balance challenges because the other foot is always skimming across the floor if  needed. 

Also, note that the transfers are always facilitating ankle dorsiflexion, just make sure you are not teaching this with knee extension lockout because it will cheat the amount of effort and wanted challenge to the anterior compartment.

We use the tai chi transfers as shown in our rehab in specific cases, but if you are dealing with the elderly, this is a great part of a daily program to reduce the fall statistics we listed earlier.  It helps the post operative cases and elderly where exactly are the limits of their safe weight shifting and where the risk zone of excessive weight shift begins.  

If you are looking for a good soft gentle way to:

1- improve balance

2- increase awareness of weight shifts that are not beyond the frontal plane stability of the hip (ie. improve awareness of the gluteus medius and lateral hip stabilizers)

3- improve the awareness of the back leg hip extension and gluteus maximus use during the forward weight transfer

4- improving anterior compartment awareness, skill and strength

5- improve weight bearing ankle rocker motion

… . then the basic tai chi walking weight transfer is an excellent start. I have taught my 80 year old parents this simple daily challenge and I think it will reduce their falls. We have used this in post operative knees and hips and it is a nice gentle start for many clients.  And when done super slow in a deep knee bend the challenges as described by our upper level athletes are surprising to both us and them.  Do tai chi for 30 minutes and learn its secret values. Millions of people around the world all can’t be wrong.

Shawn and Ivo, taking gait to new dimensions.

Podcast 40: Trips, Falls and NFL Shoe Injuries

Today we talk about trip and fall incidence, the NFL shoe injury epidemic and so much more ! Join us today on The Gait Guys podcast !

A. Link to our server:

http://thegaitguys.libsyn.com/podcast-40-trips-falls-and-nfl-shoe-injuries

B. iTunes link:

https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138

C. Gait Guys online /download store (National Shoe Fit Certification and more !) :

http://store.payloadz.com/results/results.aspx?m=80204

D. other web based Gait Guys lectures:

www.onlinece.com   type in Dr. Waerlop or Dr. Allen,  ”Biomechanics”

* Today’s show notes:

Neuroscience:

 

1. Foramen magnum position in erect ambulation

http://www.sciencedirect.com/science/article/pii/S0047248413001681

 

1b: Scientists Identify Protein Linking Exercise to Brain Health

REDDIT TOP NEWS | OCTOBER 12, 2013
http://pulse.me/s/s2PNS 

2.  More on Cannabinoids

http://www.medicaljane.com/2013/02/13/cannabinoids-breast-milk-do-cannabinoids-play-a-larger-role-in-our-life-than-we-thought/3. 

 

4. TRips and Falls 

http://online.wsj.com/article/SB10001424052702303983904579093560173066446.html

5.  NFL shoes and injuries

http://www.cbssports.com/nfl/writer/pat-kirwan/23931415/big-nfl-ir-numbers-show-more-foot-ankle-injuries-shoes-at-issue

6. From a Blog reader:

Hi guys,

I have been having major leg issues sine my ACL reconstruction  … .

Our DISCLAIMER !, hear it on the podcast. We are NOT your doctor !

7.  From a Blog reader:

Hello, I’m a 19 year old runner trying to get rid of my crossover gait … 

 

8. Another one from a blog reader

Hi, I have a question about externally rotated hip. When i bring my knee up to my chest, my leg turns outward … 

 

9.  Blog

Im really confused with GaitGguys, I follow but this time mixed messages. Recent video showed was varus/lateral boarder push off gait, girl in tennis shoes … 

 

10. National Shoe Fit program: 

http://store.payloadz.com/details/1050149-movies-and-videos-educational-shoe-fit-program-complete-parts-1-3-medical-version.html

A love letter to us !

Dear Gait Guys,

Hi, my name is Paige. I have been working in a sports medicine outpatient clinic for about 2 months now. I love your podcast and recommend it to as many clinicians as possible. I watched your youtube videos on the shuffle gait and have been implementing them into a patient’s home program. They are working great and the patient loves them as well! Just wanted to let you know! I love the videos and hope to take your shoe fit program at some point! You are geniuses and excellent instructors. I’ve learned so much already that we just don’t get enough of in school!
Thanks so much!
Paige