Impact matters: How you put your foot on the ground matters.

Impact matters. For years Ivo and I have been telling our clients this obvious fact. Over and over we hear the heavy heel strike of our barefoot clients on the floors of our office. We are constantly drawing their attention to this unnecessary impact load.  They hear it, feel it, and make immediate notable changes and realize that they are a big part of their own problem.  (Recently, an onslaught of Sever's "disease" cases have been coming into our office and the parents confirm a herd of elephants live on the upper floors of their homes, if you catch our drift. Impact matters.  Kids with heel growth plate issues should not be pounding their heels into the floors.)  We like to say, the heel can touch down first, that is ok, it is normal in walking gait, just please "kiss the floor" with the heel instead of driving nails.  But, to be fair, all those high heel EVA foam cushioned shoes have brought us to where we are, and minimalism is trending us out -- a little.  

Here in this study, they "aimed to determine if a quantifiable relationship exists between the peak sound amplitude and peak vertical ground reaction force (vGRF) and vertical loading rate during running."

They used the same queuing in the study that we use in our offices, participants were verbally instructed to run quietly compared to their normal running. What is interesting is that "simple linear regressions revealed no significant relationships between impact sound and peak vGRF in the normal and quiet conditions and vertical loading rate in the normal condition." But, read carefully. There is a subtlety in this study, there were changes when the runners were queued to run more quietly, consciously.  This was different compared to those who just unconsciously ran quieter. 

"During the normal running condition, 15.4% of participants utilized a non-rearfoot strike technique compared to 76.9% in the quiet condition, which was corroborated by an increased ankle plantarflexion angle at initial contact. "

"This study demonstrated that quieter impact sound is not directly associated with a lower peak vGRF or vertical loading rate. However, given the instructions to run quietly, participants effectively reduced peak impact sound, peak vGRF and vertical loading rate."

J Sports Sci. 2016 Sep 3:1-7. [Epub ahead of print]

Running quietly reduces ground reaction force and vertical loading rate and alters foot strike technique.

Phan X1,2, Grisbrook TL1, Wernli K1,3, Stearne SM1, Davey P1, Ng L1.