What Does Changing your Stride Cost You?

http://running.competitor.com/2013/09/training/study-changing-running-stride-does-more-harm-than-good_41136

A recent study cited in Competitor Magazine, talked about common stride “improvements” actually may reduce running economy. They looked at stride rate (cadence) and vertical displacement. One would think, with all the hoopla out there, that more steps per minute and less vertical displacement would be more efficient. The actual study concluded “Alterations led to an increase in metabolic cost in most cases, measured as VO2 uptake per minute and kg body mass,” Another study which had similar results can be found here.

Even though the study had a small sample size (16 participants), If you think about this, it makes sense.   Volitional effort usually has a metabolic cost. It does not make it right or wrong; they are just the facts. The nervous system will take time to integrate new (motor) patterns. Each person has a optimal (homestatic) stride “style” which includes vertical displacement as well as stride length, among other factors (lateral sway, ankle dorsi pantar flexion, knee flexion, thigh flexion, etc).

The study itself also concluded ““Mid- and long-term effects of altering … technique should also be studied.” we concur, we have not seen any long term studies that look at economy over time, but would love to read them if any of our readers run across them.

The Gait Guys.  Bringing you the facts without the bling.

More on the Great Debate: Does decreased step height (resulting in less vertical oscillation) increase running economy

There continues to be a plethora of conflicting data out there on the web. Yes, shocking realization !

This study looks at 16 triathletes; 8 folks trained in the “pose method” of running for 12 weeks, versus the 8 folks who just kept running in their usual fashion (ie. the control group perhaps also known as the “beer and Doritos group”  : )  ). They measured changes in stride length (decreased in posers), vertical oscillation (decreased in posers) and oxygen cost (increased in posers).

According to the study’s conclusion

“The global change in running mechanics associated with 12 weeks of instruction in the pose method resulted in a decrease in stride length, a reduced vertical oscillation in comparison with the control group and a decrease of running economy in triathletes”

Why the changes? Perhaps it takes longer to train appropriately in this method and to become efficient at the method. Perhaps when you lose the “pendulum effect” we spoke about last Thursday on the blog, you become less efficient, or maybe there is another factor. MAYBE “pose running” just isn’t more efficient. Time and more studies will tell.

The Gait Guys. Telling it like it is and bringing you the meat….without the filler

all material copyright 2013 The Gait Guys/ The Homunculus Group. Please ask before lifting our stuff.

J Sports Sci. 2005 Jul;23(7):757-64.

Effect of a global alteration of running technique on kinematics and economy.

Source

Department of Exercise Science, Health Promotion and Recreation, Colorado State University – Pueblo, Pueblo, CO, USA. george.dallam@colostate-pueblo.edu

Abstract

In this study, we examined the consequences of a global alteration in running technique on running kinematics and running economy in triathletes. Sixteen sub-elite triathletes were pre and post tested for running economy and running kinematics at 215 and 250 m.min-1. The members of the treatment group (n=8) were exposed to 12 weeks of instruction in the “pose method” of running, while the members of the control group (n=8) maintained their usual running technique. After the treatment period, the experimental group demonstrated a significant decrease in mean stride length (from 137.25+/-7.63 cm to 129.19+/-7.43 cm; P<0.05), a post-treatment difference in vertical oscillation compared with the control group (6.92+/-1.00 vs. 8.44+/-1.00 cm; P<0.05) and a mean increase in submaximal absolute oxygen cost (from 3.28+/-0.36 l.min-1 to 3.53+/-0.43 l.min-1; P<0.01). The control group exhibited no significant changes in either running kinematics or oxygen cost. The global change in running mechanics associated with 12 weeks of instruction in the pose method resulted in a decrease in stride length, a reduced vertical oscillation in comparison with the control group and a decrease of running economy in triathletes.

PMID:16195026 [PubMed – indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/pubmed/16195026

More on the Great Debate: Does decreased step height (resulting in less vertical oscillation) increase running economy

There continues to be a plethora of conflicting data out there on the web. Yes, shocking realization !

This study looks at 16 triathletes; 8 folks trained in the “pose method” of running for 12 weeks, versus the 8 folks who just kept running in their usual fashion (ie. the control group perhaps also known as the “beer and Doritos group”  : )  ). They measured changes in stride length (decreased in posers), vertical oscillation (decreased in posers) and oxygen cost (increased in posers).

According to the study’s conclusion

“The global change in running mechanics associated with 12 weeks of instruction in the pose method resulted in a decrease in stride length, a reduced vertical oscillation in comparison with the control group and a decrease of running economy in triathletes”

Why the changes? Perhaps it takes longer to train appropriately in this method and to become efficient at the method. Perhaps when you lose the “pendulum effect” we spoke about last Thursday on the blog, you become less efficient, or maybe there is another factor. MAYBE “pose running” just isn’t more efficient. Time and more studies will tell.

The Gait Guys. Telling it like it is and bringing you the meat….without the filler

all material copyright 2013 The Gait Guys/ The Homunculus Group. Please ask before lifting our stuff.

J Sports Sci. 2005 Jul;23(7):757-64.

Effect of a global alteration of running technique on kinematics and economy.

Source

Department of Exercise Science, Health Promotion and Recreation, Colorado State University – Pueblo, Pueblo, CO, USA. george.dallam@colostate-pueblo.edu

Abstract

In this study, we examined the consequences of a global alteration in running technique on running kinematics and running economy in triathletes. Sixteen sub-elite triathletes were pre and post tested for running economy and running kinematics at 215 and 250 m.min-1. The members of the treatment group (n=8) were exposed to 12 weeks of instruction in the “pose method” of running, while the members of the control group (n=8) maintained their usual running technique. After the treatment period, the experimental group demonstrated a significant decrease in mean stride length (from 137.25+/-7.63 cm to 129.19+/-7.43 cm; P<0.05), a post-treatment difference in vertical oscillation compared with the control group (6.92+/-1.00 vs. 8.44+/-1.00 cm; P<0.05) and a mean increase in submaximal absolute oxygen cost (from 3.28+/-0.36 l.min-1 to 3.53+/-0.43 l.min-1; P<0.01). The control group exhibited no significant changes in either running kinematics or oxygen cost. The global change in running mechanics associated with 12 weeks of instruction in the pose method resulted in a decrease in stride length, a reduced vertical oscillation in comparison with the control group and a decrease of running economy in triathletes.

PMID:16195026 [PubMed – indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/pubmed/16195026

The Windmill Pitch: Fastpitch Softball. More proof that arm swing and opposite leg swing are powerfully coordinated and neurologically paired.

Step length and power can affect opposite arm power and speed.

You have heard us talk often about opposite arm and leg swing pairing and how important they are from a neurological coordination issue. We have also talked about energy conservation and transmission in prior blog posts when it comes to arm swing. Good arm swing will lead to energy conservation.  A reduction in arm swing leads to a poor gait economy.  Check out this study here and the statistics. 

Collins et al Proc Biol Sci, 2009, Oct 22 “Dynamic arm swinging in human walking.”

“normal arm swinging requires minimal shoulder torque, while volitionally holding the arms still requires 12 % more metabolic energy.  Among measures of gait mechanics, vertical ground reactive moments are most affected by arm swinging and increased by 63% without arm swing.”

* type in “arm swing” into our blog SEARCH box and you will see 14 articles we have written on arm swing in human locomotion.

Gait is in every sport, just about.  Here we see a beautiful depiction of the opposite arm and leg pairing neuro-biomechanically, albeit not gait here it is still in her movement.  The larger a first step , whether the pitcher is a overhead hardball thrower or underarm fastball pitcher, the concept remains preserved.  I was a pitcher for over 10 years in the Ontario Fastball league back in Canada when I was a youth and teenager.  I was not a big speed pitcher, but what I had troubles coming up with in speed I was able to make up in putting “junk” on the ball.  My first step was large, and the larger the left step length (as seen in this video here), the more pelvic obliquity that could be achieved, which in turn enabled an opposite “anti-phase” rotation of the shoulder girdle.  When you add increased shoulder girdle obliquity with full arm rotation speed losses can be contained and limited.  Hypothetically, ball speed in a smaller player with a large first step can be heightened to the point of a that of a larger stronger pitcher with a smaller step.

Here you can see a great demonstration of this large step length the video.  They are using the tilt board to facilitate a faster downward plantarflexion of the right foot to drive a larger faster left step. It is the same principle as if you stepped off a curb or into a hole unexpectedly, the body’s natural reaction is to step out quickly with the other limb to catch the body’s forward fall. The board is used to achieve the same result with control. This is why you will see pitchers dig out a trench immediately in front of the pitchers rubber, to create this same plantarflexion drop of the right foot (in this case, the right foot for a right handed pitcher).  The deeper the trench, the more aggressive that left step.

Shawn and Ivo………..digging deep trenches today…….. and finding gait theory everywhere, even in fastball.

http://youtu.be/QzojfAUcGEI

http://youtu.be/0OA6RfTre6M

Slow Your Gait & Shorten Your Stride and Your Brain May Slow

Slow Your Gait & Shorten Your Stride and Your Brain May Slow

Well, you have heard it here before, the receptors drive the brain, and here is another study that backs this up. Remember that receptors, which include not only joint mechanoreceptors, but also muscle mechanoreceptors (muscle spindles and golgi tendon organs) and tactile receptors in the skin (Merkels discs, paccinian corpuscles, etc) feed into the brain cortex (via the dorsal column system) and the cerebellum (via the spino cerebellar system). This afferent (sensory information) input is important for proper coordination as well as cognition and learning.

Remember, your brain is always remodeling. Here, the old adage “if you don’t use it, you will lose it” applies. More input = more synapses = more neuronal growth. So less motion = less input=synaptic atrophy = fewer connections and thus slower brain function.

Increased speed and length of stride stretches receptors more; decreased speed and shorter stride lengths decrease receptor activation. So, take big steps quickly, or you may turn into a zombie ! There is a reason why they walk slowly !

In July 2012 at the Alzheimer’s Association International Conference in Vancouver, British Columbia Mayo Clinic researchers presented research indicating that walking problems such as a slow gait and short stride are associated with an increased risk of cognitive decline. Computer assessed gait parameters (stride length, cadence and velocity) in study participants at two or more visits roughly 15 months apart. They revealed that participants with lower cadence, velocity and length of stride experienced significantly larger declines in global cognition, memory and executive function.

references:

http://www.aansneurosurgeon.org/2012/08/02/slow-gait-short-stride-linked-to-increased-risk-of-cognitive-decline/

http://www.newswise.com/articles/view/591437/?sc=dwhn

Slow Your Gait & Shorten Your Stride and Your Brain May Slow

Slow Your Gait & Shorten Your Stride and Your Brain May Slow

Well, you have heard it here before, the receptors drive the brain, and here is another study that backs this up. Remember that receptors, which include not only joint mechanoreceptors, but also muscle mechanoreceptors (muscle spindles and golgi tendon organs) and tactile receptors in the skin (Merkels discs, paccinian corpuscles, etc) feed into the brain cortex (via the dorsal column system) and the cerebellum (via the spino cerebellar system). This afferent (sensory information) input is important for proper coordination as well as cognition and learning.

Remember, your brain is always remodeling. Here, the old adage “if you don’t use it, you will lose it” applies. More input = more synapses = more neuronal growth. So less motion = less input=synaptic atrophy = fewer connections and thus slower brain function.

Increased speed and length of stride stretches receptors more; decreased speed and shorter stride lengths decrease receptor activation. So, take big steps quickly, or you may turn into a zombie ! There is a reason why they walk slowly !

In July 2012 at the Alzheimer’s Association International Conference in Vancouver, British Columbia Mayo Clinic researchers presented research indicating that walking problems such as a slow gait and short stride are associated with an increased risk of cognitive decline. Computer assessed gait parameters (stride length, cadence and velocity) in study participants at two or more visits roughly 15 months apart. They revealed that participants with lower cadence, velocity and length of stride experienced significantly larger declines in global cognition, memory and executive function.

references:

http://www.aansneurosurgeon.org/2012/08/02/slow-gait-short-stride-linked-to-increased-risk-of-cognitive-decline/

http://www.newswise.com/articles/view/591437/?sc=dwhn

This week we will focus on the basics of gait and the gait cycle in our attempt to assist in gait literacy

Gait Cycle Basics: Part 1

Steps and strides….

What does the gait cycle that have to do with therapy or rehabilitation? Well, most people walk at some point in the day, and most have walked into your office. If people can’t carry the changes you made on the table and incorporate it into walking, then what you do will have limited effectiveness. Thus, the need for understanding the gait cycle as it relates to rehabilitation or how it can give you clues to the biomechanical faults present. An example is a loss of functional hip extension and chronic LBP/ SI dysfunction. This could be due to a myriad of reasons, from weak glutes, loss of ankle dorsiflexion, or even a dysfunctional shoulder. Understanding how these seemingly unrelated body parts integrate into the kinetic chain, especially while moving upright through the gravitational plane.

 

One gait cycle consists of the events from heel strike to heel strike on one side. A step length is the distance traveled from one heel strike to the next (on the opposite side). Comparing right to left step lengths can give the evaluator insight into the symmetry of the gait.  Differences in step length, on the simplest level, should cause the individual to deviate consistently from a straight line (technically it should cause the individual to eventually walk in a large circle!).  Often, compensations occur functionally in the lower kinetic chain to compensate for the differences in step length to ensure that you walk in a straight line.  It is these longstanding complex compensations that are the generators of many of our patient’s complaints.

 

A stride length is the distance from heel strike to heel strike on the ipsilateral side (the distance covered in one gait cycle.  Step width, or base of gait, is the lateral distance between the heel centers of two consecutive foot contacts (this typically measures 6-10 cm).  Foot progression angle is the angle of deviation of the long axis of the foot from the line of progression (typically 7-10 degrees). Çhanges in the progression angle can be due to both congenital (torsions, versions) as well as developmental reasons.

Next time we will take a closer look at the gait cycle itself. Yup, we are still…The Gait Guys

special thanks to Dr. Tom Michaud, who has allowed us to use these images in our book