Ankle sprains and the reorganization of the sensorimotor system

“Our subjects with unilateral chronic ankle sprains had weaker hip abduction strength and less plantar-flexion range of motion on the involved sides. Clinicians should consider exercises to increase hip abduction strength when developing rehabilitation programs for patients with ankle sprains.”-Friel et al

Awhile back we wrote about the principle that if the hip abductors are weak, the leg will posture more adducted (ie, cross over type pattern) and this places the foot more directly below the body midline plumb, this will posture the foot in inversion and thus at greater risk for future inversion sprains.  This sets up the vicious cycle of hip abductor weakness, frontal plane drift of pelvis, inversion of the foot and more ankle sprain risks/events.  The cycle must be broken. The hip must be addressed. That lateral chain must be restored all the way up from the foot.  

Another newer study by Bowker discusses the somatosensory feedback necessary for postural adjustments, walking, and running stating that they may be hampered by a decrease in soleus spinal reflex excitability.  The study adds more validity to what we are all growing to know more clearly, that the central nervous system via supraspinal circuitry plays deeply into chronic ankle instability (CAI). The studies suggest that CAI may be more about coordination and control of dynamic stabilizers and changes in the motor neuron excitability rather than the function of static stabilizers.

“A successful reorganization of the sensorimotor system after an initial ankle sprain is the critical point when individuals suffer chronic ankle instability or become copers [individuals who do not develop chronic instability after an ankle sprain] who break the cycle of recurrent injuries and disabilities seen in CAI,” Masafumi Terada, PhD

According to LER and the Terada work, 

The slow-twitch fibers in the soleus muscle are mostly innervated by small alpha motoneurons, Terada explained, so the study findings suggest that some people may restore their ability to reflexively recruit alpha motoneurons after ankle injury, and some may not.

“Therapeutic interventions that can increase the H-reflex in the soleus may help to break the cycle of recurrent injuries and disabilities seen in CAI,” he said. “Lower-intensity transcutaneous electrical stimulation, joint manipulations, and reflex conditioning protocols may be effective in increasing the soleus spinal excitability.”

The Gait Guys

Reference:

CAI and the CNS: Excitability may influence instability. Larry Hand

http://lermagazine.com/news/in-the-moment-sports-medicine/cai-and-the-cns-excitability-may-influence-instability

Taken from original source:

Bowker S, Terada, M, Thomas AC, et al. Neural excitability and joint laxity in chronic ankle instability, coper, and control groups. J Athl Train 2016 Apr 11. [Epub ahead of print]

J Athl Train. 2006; 41(1): 74–78.PMCID: PMC1421486Ipsilateral Hip Abductor Weakness After Inversion Ankle SprainKaren Friel,Nancy McLean,Christine Myers, and Maria Caceres
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1421486/

The diaphragm and chronic ankle instability.

I have been treating the global manifestations of unaddressed chronic ankle sprains for decades now. I am never unsurprised to find frontal plane hip weakness and dysfunction of the same side obliques , shoulder and spinal stabilizers. Here is one more piece of proof that unaddressed ankles are monster problems, slowly eroding the stability of the system.
But, shame on those who attempt to simplify this, just correcting the breathing and throwing some corrective spinal stability work at this problem. This approach will fail, repeatedly. At some point the ankle has to be addressed and the impaired supra spinal programming. Gait will have to be retrained as well, forget to do this and your efforts will be muted.
-Dr. Allen

“Previous investigations have identified impaired trunk and postural stability in individuals with chronic ankle instability (CAI). The diaphragm muscle contributes to trunk and postural stability by modulating the intra-abdominal pressure. A potential mechanism that could help to explain trunk and postural stability deficits may be related to altered diaphragm function due to supraspinal sensorimotor changes with CAI.”

Reference:

Diaphragm Contractility in Individuals with Chronic Ankle Instability.

Terada, Masafumi; Kosik, Kyle B.; McCann, Ryan S.; Gribble, Phillip A.  Medicine & Science in Sports & Exercise:

http://journals.lww.com/acsm-msse/Abstract/publishahead/Diaphragm_Contractility_in_Individuals_with.97497.aspx

Dry Needling and Proprioception. What a great combination.

Since dry needling and proprioception both have such profound effects on muscle tone, why not combine them to treat chronic ankle instability? We do all the time and here is a FREE FULL TEXT article that ties the two together nicely!

And what better to muscle to use than the peroneii? These babies help control valgus/varus motions of the foot and influence plantar and dorsiflexion AND the longus descends the 1st ray. We call that a triple win!

“This study provides evidence that the inclusion of TrP-DN within the lateral peroneus muscle into a proprioceptive/strengthening exercise program resulted in better outcomes in pain and function 1 month after the end of the therapy in individuals with ankle instability. Our results may anticipate that the benefits of adding TrP-DN in the lateral peroneus muscle for the management of ankle instability are clinically relevant as large between-groups effect sizes were observed in all the outcomes.”

link to full text
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4430654/

photo from this past weekends Dry Needling Seminar: working on the dorsal interossei

Hmmmm…

The question is: “is the earlier activation a good thing”?

What do you say?

“A study of patients with chronic ankle instability (CAI) suggests the onset of knee and ankle muscle activity occurs significantly earlier when shoes and orthoses are worn than when the patients are barefoot.”

http://lermagazine.com/issues/october/shoes-orthoses-improve-muscle-activation-onset-in-unstable-ankles

Podcast 95: Head tilt while squatting or running.

We have a strong show for you today. Ankle instability from a neurologic perspective, shoe wear, head tilt and the neurologic and functional complications… we also talk about Efferent Copy and motor learning.

A. Link to our server:
http://traffic.libsyn.com/thegaitguys/pod_95final.mp3

Direct Download:  http://thegaitguys.libsyn.com/pod-95

-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 & 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”

-Our Book: Pedographs and Gait Analysis and Clinical Case Studies
Electronic copies available here:

-Amazon/Kindle:
http://www.amazon.com/Pedographs-Gait-Analysis-Clinical-Studies-ebook/dp/B00AC18M3E

-Barnes and Noble / Nook Reader:
http://www.barnesandnoble.com/w/pedographs-and-gait-analysis-ivo-waerlop-and-shawn-allen/1112754833?ean=9781466953895

https://itunes.apple.com/us/book/pedographs-and-gait-analysis/id554516085?mt=11

-Hardcopy available from our publisher:
http://bookstore.trafford.com/Products/SKU-000155825/Pedographs-and-Gait-Analysis.aspx

Show notes:

Human exoskeletons: The Ekso
http://www.thedailybeast.com/articles/2015/08/03/the-mechanical-exoskeleton-shaping-the-future-of-health-care.html

Ankle muscle strength influence on muscle activation during dynamic and static ankle training modalities
http://www.tandfonline.com/doi/abs/10.1080/02640414.2015.1072640?rfr_id=ori%3Arid%3Acrossref.org&url_ver=Z39.88-2003&rfr_dat=cr_pub%3Dpubmed&#.VcYWR-1VhBc

Chronic ankle instability:

http://tmblr.co/ZrRYjx1akudcm

http://tmblr.co/ZrRYjx1ah6ThV

http://thegaitguys.tumblr.com/post/68785250796/just-because-a-muscle-tests-weak-doesnt-mean-it
http://thegaitguys.tumblr.com/post/117109093439/last-week-we-ran-an-archived-piece-named-just

the future of footwear and orthotics ?
http://lermagazine.com/special-section/conference-coverage/the-future-of-footwear-and-orthoses-is-here-now-what

squats- head posture-gait vision-gravity
http://thegaitguys.tumblr.com/search/vision

Music: brain rhythm
http://www.kurzweilai.net/the-brains-got-rhythm

Who’d a thought? Can someone make an “app” for that?

Interesting study that we just found out about in the June 15th LER journal titled “Patients with ankle instability respond to auditory feedback by changing gait”

In this study they put a sensor under the head of the 5th metatarsal in 10 folks with chronic ankle instability that would emit a sound in respose to excessive lateral ankle pressure. They were told to “walk quietly” and not let the beeper beep. After a short time, the people in the study were able to walk with decreased pressures in the lateral forefoot, in addition to the midfoot and central forefoot. EMG showed increase in peroneal and medial gastroc activity.

Interesting implications and also some questions.

This study shows that auditory feedback can alter behavior and gait. Is this a good thing? We suppose this depends on what you are trying to accomplish and does it ultimately benefit the patient?

this sensor could be made into an “app” that has some cool rehabilitation implications. Imagine a moveable sensor or multiple sensors that could track patterns over time and plot them for you? The auditory could be used to discourage some bevaiors/characteristics of gait and the “tracking” feature could provide progress information. Or maybe is it hooked up to some of your favorite music and it stops playing when you are not weighting appropriately. Wondering if your patient is loading the head of the 1st metatarsal? This could provide some feedback.

Check it out:

Donovan l, Hart JM, Saliba S et al. Effects of an auditory feedback device on plantar pressure in participants with chronic ankle instability. Med Sci Sports Exerc 2015; 46(5 suppl); S104

CAI: More on Chronic Ankle Instability.

More peroneii action! In folks with chronic ankle instability, it contracts earlier, longer (throughout stance phase) but not stronger…This article looks at activation times and patterns of folks with chronic ankle instability. 

One should never wonder why repeated ankle sprains occur. We have hit this topic hard in the past.  Chronic Ankle Instability (CAI) clients exhibit prioprioceptive and postural control challenges. According to this article, additionally, CAI clients have gait. 

Time of activation for all muscles tested occurred earlier in the CAI group than in the control group. The peroneus longus was activated for a longer duration across the entire stride cycle in the CAI group.”

Individuals with CAI demonstrated neuromuscular-activation strategies throughout the lower extremity that were different from those of healthy control participants. “

Did you see our trademark “goto” exercise in yesterday’s social media Facebook blog post ?  It is a keeper if you ask us.  Don’t ignore chronic peroneal challenges, they will come back to haunt you.

_________

Lower Extremity Muscle Activation in Patients With or Without Chronic Ankle Instability.  Mark A. FegerMEd, ATCLuke DonovanMEd, ATCJoseph M. HartPhD, ATCJay HertelPhD, ATC, FNATA, FACSM Department of Kinesiology, The University of Virginia, Charlottesville

http://www.natajournals.com/doi/abs/10.4085/1062-6050-50.2.06 

Results:  Time of activation for all muscles tested occurred earlier in the CAI group than in the control group. The peroneus longus was activated for a longer duration across the entire stride cycle in the CAI group (36.0% ± 10.3%) than the control group (23.3% ± 22.2%; P = .05). No differences were noted between groups for measures of electromyographic amplitude at either preinitial or postinitial contact (P > .05).

Conclusions:  We identified differences between the CAI and control groups in the timing of muscle activation relative to heel strike in multiple lower extremity muscles and in the percentage of activation time across the entire stride cycle in the peroneus longus muscle. Individuals with CAI demonstrated neuromuscular-activation strategies throughout the lower extremity that were different from those of healthy control participants. Targeted therapeutic interventions for CAI may need to be focused on restoring normal neuromuscular function during gait.