Speed Matters: Brief Thoughts on Gait and Running.

The journal article below sparked a few thoughts for a blog post today.

Have you ever tried to walk slower than your normal pace ? How about running slower than your normal pace (  you know, running with that person who is clearly a minute slower pace) ? Why are both so uncomfortable and labor intensive ? Why does your balance, energy and stability become challenged ? After all, slower should be easier right ?!
There are many reasons and this study hints at a few issues but the bottom line is that speed matters.  Have you ever been driving down the road and you see a big pot hole in the road that you just cannot get around because it is either too big or you do not have time to steer around it ?  What is your first reaction ?  Many will press down on the gas pedal. Why is that ? Well, logic for many is that speeding up will possibly enable you to launch across the void and reduce the impact issues of dropping down into the void.  Men will rationalize the “launch across the pothole” theory, and in some respects they are not wrong.
Running and walking slowly sort of bring out some of the same issues.  When we move slowly the body is more likely to drift into the frontal/coronal (side to side) plane.  Moving more quickly ensures that the dominant path is forward. Slowing down does not ensure that forward will occur. side to side sway enters the picture. And when side to side sway enters as an option we have to spend more time and strategies negotiating the side sway.  This is why we see all kinds of corrections with the limbs and core when we attempt to stand on one foot, but we do not see these issues when we walk or run.  When running we are mostly trying to get the next foot underneath our body so that we do not fall forward flat on our face. Locomotion is a strategy of nothing more than trying to stay upright.  When we run the predominant motion is forward. But when we slow down and reduce the advantage of speed to blur out these issues the challenges begin and other planes of movement become an option and thus planes we need to control. It is much why the elderly have more difficulty moving about, because they have to negotiate and control so many other planes of movement.
So, if you want to bring out some faulty motor patterns, move more slowly and see where your deficits lie. One of our assessments for patients and athletes is to have them walk at a 3second pace meaning each foot fall must be held for 3 seconds before the next step can be initiated. This means stance and swing must be slowed to 3 seconds.  Amazing things will show up if you just slow things down and allow weaknesses to percolate to the surface.  Speed blurs them and keeps them suppressed. It is really a form of cheating and compensation.
So, like in your car, speed matters.
Think about this next time you have to walk or run with a slower person. It may be one of the issues, but there are others and we will eventually get to them.

Gait and Speed on Child Development
J Biomech. 2008;41(8):1639-50. Epub 2008 May 7. The effect of walking speed on the gait of typically developing children. Schwartz MH, Rozumalski A, Trost JP. Abstract

Many gait studies include subjects walking well below or above typical self-selected comfortable (free) speed. For this reason, a descriptive study examining the effect of walking speed on gait was conducted. The purpose of the study was to create a single-source, readily accessible repository of comprehensive gait data for a large group of children walking at a wide variety of speeds. Three-dimensional lower extremity joint kinematics, joint kinetics, surface electromyographic (EMG), and spatio-temporal data were collected on 83 typically developing children (ages 4-17) walking at speeds ranging from very slow (>3 standard deviations below mean free speed) to very fast (>3 standard deviations above mean free speed). The resulting data show that speed has a significant influence on many measures of interest, such as kinematic parameters in the sagittal, coronal, and transverse planes. The same was true for kinetic data (ground reaction force, moment, and power), normalized EMG signals, and spatio-temporal parameters. Examples of parameters with linear and various nonlinear speed dependencies are provided. The data from this study, including an extensive electronic addendum, can be used as a reference for both basic biomechanical and clinical gait studies.