Asymmetry seems to matter with pathology.

image credit: https://commons.wikimedia.org/wiki/File:PSM_V46_D167_Outer_surface_of_the_human_brain.jpg

When you have low back pain, your gait is apt to be asymmetrical

...And that is just what this study showed. It looked at 82 right leg dominant folks with slightly less than 1/2 of them havong low back pain. The folks with lower back pain spent more time on their non dominant leg at the beginning of a gait cycle and on their dominant leg at the end of it. Not surprising that they wanted to find a more stable base or center their COP over the weight bearing foot, especially in light to the fact that the back has such poor cortical representation.

Sung PS, Danial P. A Kinematic Symmetry Index of Gait Patterns Between Older Adults With and Without Low Back Pain. Spine (Phila Pa 1976). 2017 Dec 1;42(23):E1350-E1356. doi: 10.1097/BRS.0000000000002161.

The next time they have gait asymmetry, try changing out the insole...

or putting a textured one in there...or maybe putting a some sand or dirt in their shoe...

image credit: https://torange.biz

Textured insoles change (we like to think for the better) proprioceptive input and can improve balance and gait performance, both statically and dynamically. We have seen this in folks with parkinsons (1) as well as stroke (2), though it can be used in the elderly (3), in diabetes and neuropathy (4), as well as healthy individuals (5,6). Changes from postural stability, to changes in anterior/posterior sway, to medial/lateral sway, to step length and height, the research is there.

These results support the hypothesis that enhanced somatosensory feedback to the sensory system, both through the spinocerebellar and dorsal column pathways, as well as the vestibular system, results in an improved motor output (and most likely coordination) of gait.

1. Qiu F, Cole MH, Davids KW, et al. Effects of textured insoles on balance in people with Parkinson's disease. PLoS One. 2013;8(12):e83309. Published 2013 Dec 12. doi:10.1371/journal.pone.00833

2. Ma CC1, Rao N2, Muthukrishnan S3, Aruin AS4. A textured insole improves gait symmetry in individuals with stroke. Disabil Rehabil. 2017 Aug 7:1-5. doi: 10.1080/09638288.2017.1362477. [Epub ahead of print]

3. Annino G1,2,3, Palazzo F2, Alwardat MS4, Manzi V5, Lebone P2, Tancredi V1,2,3, Sinibaldi Salimei P2,6,7, Caronti A2, Panzarino M2,3, Padua E2,3. Effects of long-term stimulation of textured insoles on postural control in health elderly. J Sports Med Phys Fitness. 2018 Apr;58(4):377-384. doi: 10.23736/S0022-4707.16.06705-0. Epub 2016 Sep 15.

4. Paton J, Glasser S, Collings R, Marsden J. Getting the right balance: insole design alters the static balance of people with diabetes and neuropathy. J Foot Ankle Res. 2016;9:40. Published 2016 Oct 5. doi:10.1186/s13047-016-0172-3

5. Steinberg N1, Tirosh O, Adams R, Karin J, Waddington G. Influence of Textured Insoles on Dynamic Postural Balance of Young Dancers. Med Probl Perform Art. 2017 Jun;32(2):63-70. doi: 10.21091/mppa.2017.2012.

6. Collings R1, Paton J2, Chockalingam N3, Gorst T2, Marsden J2. Effects of the site and extent of plantar cutaneous stimulation on dynamic balance and muscle activity while walking. Foot (Edinb). 2015 Sep;25(3):159-63. doi: 10.1016/j.foot.2015.05.003. Epub 2015 May 11.

More asymmetrical thoughts

Again, in this study, like the last we discussed here, we are looking at experienced (and in this case, young) runners; sprinters specifically. Again, they ran relatively short distances (20 meters). More than 1/2 the runners had “large” asymmetries, and they all had asymmetries of some type. Some athletes had injuries and some did not.

There wasn’t a difference in sprint performance over this short distance. This is not surprising in light of the previous paper we discussed; asymmetries seem to worsen over time (Hanley 2018). The level of compensation present (since these are experienced runners) may also be better; the folks that were uninjured having compensation patterns that were more in line with their anatomy, than the injured ones.

• The asymmetries did not change. Thinking about anatomy, especially with hard deformities like torsions or versions, why would they? You can’t change the stripes on a tiger.

• Injured and non injured athletes did not differ in asymmetry before or after the study. Again, why would they? We are talking about gait changes (or perhaps compensations). What is significant for one individual (tibial torsion, femoral retroversion, leg length discrepacy) may not be as significant as it for another, depending on the compensation present.

The study concludes “... kinematic asymmetries in the stride cycle were not associated with neither maximal sprint running performance nor the prevalence of injury among high-level athletic sprinters.” Note that they are talking about prevalence of injury, not incidence of injury.

We still think that asymmetry matters...

Haugen T, Danielsen J, McGhie D, Sandbakk Ø, Ettema G. Kinematic stride cycle asymmetry is not associated with sprint performance and injury prevalence in athletic sprinters. Scand J Med Sci Sports. 2018 Mar;28(3):1001-1008. doi: 10.1111/sms.12953. Epub 2017 Aug 15.

More on Stretching? Enough already, eh?

The last few weeks , we have been talking about techniques to improve your (or your clients) stretching experience. 1st, we talked about reciprocal inhibition here. Next we talked about post isometric inhibition here. The we spoke about the symmetrical tonic neck reflex (response) here. If there is a symmetrical tonic neck reflex, then there must be an asymmetrical one as well, eh? That is the topic of todays discussion. 

The asymmetrical tonic neck reflex was 1st described by Magnus and de Kleyn in 1912 (1). Like in the pictures above, when the head is rotated to one side, there is ipsilateral extension of the upper and lower extremity on that side, and flexion of the contralateral (the side AWAY from where you are rotating) upper and lower extremity. Take a few minutes to see the subtleness of the reflex in the pictures above. Now think about how this occurs in your clients/patients.  The reflex is everywhere!

The reflex persists into adulthood (2) and is modulated by both eye movement and muscular activity (3). When there is neurological compromise, the reflex can be more prevalent, and it seems to arise from the joint mechanoreceptors in the neck and its connection to the reticular formation of the brainstem (4). It may modulate blood flow and cardiovascular activity as well (5). 

So, how can we take advantage of this? We could follow in the footsteps of Berta Bobath (6) and incorporate these into our rehabilitation programs, which we have done, quite successfully. But rather than read a whole book, lets talk about how you could incorporate this into your stretching program. 

Let’s say you want to stretch the right hamstring:

• actively rotating the head to the right (see reference 3) facilitates the right tricep and right quadricep AND facilitates the left bicep and left hamstring
• through reciprocal inhibition, this would inhibit the right bicep and hamstring AND left tricep and left quadricep
• To get a little more out of the stretch, you could actively contract the right tricep and quadricep (MORE reciprocal inhibition), amplifying the effect

We encourage you to try this, both on yourself and your clients. It really works!

Wow, isn’t neurology cool? And you thought it was only for geeks!

The Gait Guys. Giving you info you can use in a practical manner, each and every post. Be a geek. Spread the word. 

1. http://www.worldneurologyonline.com/article/arthur-simons-tonic-neck-reflexes-hemiplegic-persons/#sthash.6QS3Eat3.dpuf 

2. Bruijn SM¹, Massaad F, Maclellan MJ, Van Gestel L, Ivanenko YP, Duysens J. Are effects of the symmetric and asymmetric tonic neck reflexes still visible in healthy adults?Neurosci Lett. 2013 Nov 27;556:89-92. doi: 10.1016/j.neulet.2013.10.028. Epub 2013 Oct

3. Le Pellec A¹, Maton B. Influence of tonic neck reflexes on the upper limb stretch reflex in man. J Electromyogr Kinesiol. 1996 Jun;6(2):73-82.

4. Michael D. Ellis, Justin Drogos, Carolina Carmona, Thierry Keller, Julius P. A. Dewal Neck rotation modulates flexion synergy torques, indicating an ipsilateral reticulospinal source for impairment in stroke Journal of NeurophysiologyDec 2012,108(11)3096-3104;DOI: 10.1152/jn.01030.2011

5. Hervé Normand, Olivier Etard and Pierre Denise Otolithic and tonic neck receptors control of limb blood flow in humans J Appl Physiol  82:1734-1738, 1997.

6. Berta Bobath, Chartered Society of Physiotherapy (Great Britain)  Abnormal postural reflex activity caused by brain lesions Aspen Systems Corp. Rockville, MD, 1985 -