To drop or not to drop...That is the question...

Like to run in Zero Drop shoes? Good... we do too... but look at this:

"Barefoot running induced higher loading rates during overground running than the highest drop condition, while it was the opposite during treadmill running. Ankle plantar flexion and knee flexion angles at touchdown were higher during treadmill than overground running for all conditions, except for barefoot which did not show any difference between the tasks."

So, if you want to reduce vertical loading rates, run barefoot on a treadmill.

Does this mean if we want to decrease vertical loading rates when running overground (NOT on a treadmill) we should run in shoes with a large drop?

It seems, according to this study, that kinematics are the same with barefoot but not with shoes.

Which is best for you? You decide...

http://link.springer.com/article/10.1007%2Fs00421-014-3072-x

A great, FREE, full text on forward and backward walking kinematics and a possible link to central pattern generators.

“Leg kinematics during backward walking (BW) are very similar to the time-reversed kinematics during forward walking (FW). This suggests that the underlying muscle activation pattern could originate from a simple time reversal, as well…

"We concluded that the changes in muscle contributions imply that a simple time reversal would be insufficient to produce BW from FW. We therefore propose that BW utilizes extra elements, presumably supraspinal, in addition to a common spinal drive. These additions are needed for propulsion and require a partial reconfiguration of lower level common networks.”

http://jn.physiology.org/content/107/12/3385

Similar muscles contribute to horizontal and vertical acceleration of center of mass in forward and backward walking: implications for neural controlKaren Jansen, Friedl De Groote, Firas Massaad, Pieter Meyns, Jacques Duysens, Ilse JonkersJournal of Neurophysiology Published 15 June 2012 Vol. 107 no. 12, 3385-3396 DOI: 10.1152/jn.01156.2011

Now here is something a little different. Check out this PhD Thesis submission. What you do DOES make a difference! as we have been saying: it is a cortical phenomenon.

http://www.graduate.technion.ac.il/heb/StudentsLec/amir%20haim/abstract.htm

Plasticity of Locomotor Patterns & Gait Conditioning via Controlled

Biomechanical intervention  

Amir Haim, MD (Ph.D candidate)

Supervisor: Dr. Alon Wolf

Biorobotics and Biomechanics Lab,  Faculty of Mechanical Engineering

Overall, the task of walking is attained by a proper kinematic trajectory command conveyed by the nervous system to its skeleto-muscular instruments which generate the appropriate kinetics. Extensive evidence indicates that motor program adaptations can compensate for losses in mechanical integrity through altered movement and muscle activation patterns. Further more, non surgical biomechanical manipulations, have been shown influence kinetic and kinematic parameters and to generate “active”-neuromuscular re-education. 

In the present study we hypothesized that specific biomechanical challenges will stimulate matching biomechanical responses trough out the musculoskeletal kinematic chain. We further hypothesized that repetitive exposure to a biomechanical stimulus would generate  a process of motor learning thus conveying  plasticity of existing  locomotor patterns and gait strategies.

To test our hypothesis; we examined two cohorts - healthy young male adults and subjects suffering from knee Osteoarthritis (OA). All participants underwent gait analysis comprising kinematic kinetic and ellcetromygragic patterns during gait. We modeled the direct locomotor response to controlled footwear-generated biomechanical manipulations utilizing a novel biomechanical apparatus comprising four modular elements . Further more we prospectively examined (via gait analysis and valid questioners) patients with abnormal gait patterns (due to knee osteoarthritis) who were subjected to extended biomechanical intervention.

Study results confirmed our hypothesis; A direct association was found between specific biomechnical challenges and  direct kinetic and kinematic response in both healthy and OA subjects. Like wise, OA participants who where exposed to long term biomechanical interventions exhibited normalization of cartelistic gait patterns and had a favorable subjective outcome. 

http://www.oandp.org/jpo/library/1993_02_039.asp

http://emedicine.medscape.com/article/320160-overview

http://books.google.com/books?id=S2YVKbu77uQC&pg=PA123&lpg=PA123&dq=altered+motor+patterns+and+gait&source=bl&ots=xY7jGQDXA4&sig=6HmLZRimLVjoc_iFjuWaWTjZdUo&hl=en&ei=iFqWS6yrB4vysgOx1LzCAQ&sa=X&oi=book_result&ct=result&resnum=6&ved=0CCMQ6AEwBTgK#v=onepage&q=altered%20motor%20patterns%20and%20gait&f=false

http://jn.physiology.org/cgi/content/full/80/4/1868

http://uppercervicaldr.com/wordpress/?p=58

So, does the angle your foot strikes the ground really matter? With all the talk about minimalistic training and striking under the body being less stress on the human frame and more efficient, you would think so. Here is one study that seems to support that premise.

from the studies conclusion: “Our results indicate that individuals with a larger knee angle (i.e., greater extension) 50 ms prior to initial contact (IC) experience a higher ROL  (Rate of loading) during gait and have poorer proprioceptive scores.”

Proprioception, gait kinematics, and rate of loading during walking: are they related? Riskowski JL, Mikesky AE, Bahamonde RE, Alvey TV 3rd, Burr DB.

J Musculoskelet Neuronal Interact. 2005 Oct-Dec;5(4):379-87.

http://www.ncbi.nlm.nih.gov/pubmed/16340143

Helping to promote gait literacy…We are…The Gait guys