Is there any appreciable, real-world reduction in impact to a
runner's, joints, by running (wearing running shoes) on an asphalt
street versus a concrete sidewalk - or have street runners bought into
the 'Big Myth' (while increasing their risk of being hit by a vehicle)?

Although it makes sense that asphalt would be somewhat less jarring;
is the impact reduction significant enough to make a difference for
runners' joint health, OR are we really talking a .001% reduction WITH
A PLACEBO EFFECT ONLY?

SPECIFICS/DATA PLEASE.

Thank you very much.

Hi cvcope-ga,

Thanks for your question.

There has been some research done on this subject. I've endeavored to
find some scholarly as well as some less clinical material for you. On
the whole, the conventional wisdom that concrete is more damaging than
asphalt as a running surface seems to be correct.

"The forces generated at heel strike are dissipated through the
musculoskeletal system. Harder surfaces result in increased pounding
and subsequent deleterious effects." Because of this, something like
concrete is far less forgiving than asphalt.

Running Injuries -- Starting Off on the Right Foot -- Part II
http://www.chiroweb.com/archives/10/18/17.html

According to an article in "Men's Fitness," a clinical study found
that improper running surfaces were one of the five leading causes of
injury. What may be of interest more specifically, is that depending
on the type of running one does, the types of muscles that are
problematic or the types of injuries that one is prone to, a running
surface that is inappropriate for one person is suitable for another.
Concrete, however, has nothing to recommend itself for except safety
and smoothness.

Two of the podiatrists quoted in the article believe that "the ideal
surface is smooth and moderately (but not too) soft, and the worst is
rock hard, like concrete, or irregular, like the gravelly shoulder of
a crowned or banked road." There is also a chart provided of an
assortment of running surfaces with their pros and cons.

"Ground Rules: Limit the Risk of Injury and Keep Your Cardio Efforts
Going Full Steam Ahead by Picking the Right Running Surface Every
Time," by Bob Cooper. Men's Fitness, June 2002.
http://www.findarticles.com/cf_0/m1608/6_18/86233362/p1/article.jhtml?term=%22running+surfaces%22

According to an article in "The Physician and Sportsmedicine,"
"Running on rigid surfaces can impose stress on the body and can
result in injuries." Too soft a surface (their example was sand) is
not advisable either. Asphalt allows "good foot control and provides
even terrain."

"A Hard Look at Running Surfaces," by Robert D. Chadbourne. The
Physician and Sports Medicine, vol. 18, issue 7, pp 102-106, July
1990.

Dr. John Pagliano (the podiatrist quoted in the Men's Fitness article
above), who also coauthored a scholarly article on Illiotibial Band
Syndrome) comes down against concrete, saying that "if you switch to
softer surfaces, you can cut your injury risk by 50%." In this
particular article, the magazine rates ten running surfaces (1 being
worst/10 being best)--I realize your question is specific to street
running, but I'm including all of the surfaces here in case it's of
interest:

Asphalt: 6
Cinders: 7.5
Concrete: 1
Dirt: 8
Grass: 9.5
Sand: 4
Snow: 2.5
Track (referring to synthetically made tracks): 7
Treadmill: 6.5
Wood Chips: 9

"Judging a Path by It's Cover: Not All Running Surfaces Are Created
Equal," by Marc Bloom. Runner's World, vol. 32, issue 3, pp 54-58,
March 1997.

A softer running surface may help prevent ITB or Illiotibial Band
Syndrome.

Band Aid
http://www.runnersworld.com/home/0,1300,1-78-79-2861,00.html

This may be of interest, although the study did not look at concrete
specifically. A study published in 2000 for "Medicine & Science in
Sports & Exercise" compared three surfaces: conventional asphalt,
rubber-modified asphalt and an acrylic sports surface. The study did
find that there was "a clear mechanical difference in the impact
absorbing ability of the three sports surfaces."

"Surface Effects on Ground Reaction Forces and Lower Extremity
Kinematics in Running," by Sharon J. Dixon, Andrew C. Collop and Mark
E. Batt. Medicine & Science in Sports & Exercise, vol. 32, issue 11,
November 2000, pp 1919-1926. PMID 11079523
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11079523&dopt=Abstract

And another abstract that might be of interest:

"The Biomechanics of Running on Different Surfaces," by R.V. Feehery,
Jr. Clinics in Podiatric Medicine and Surgery, vol. 3, issue 4, pp
649-659, October 1986.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2946394&dopt=Abstract

Some of the above articles are not online for free. If you have access
to a large public or academic library, you may be able to obtain these
either through the library's collection or through Interlibrary loan.

Search strategy:
Google search:
running surfaces concrete
running surfaces injuries
running surfaces asphalt
PubMed search http://www.ncbi.nlm.nih.gov/pubmed/
Findarticles.Com
Also checked a few article databases

I hope this answers your question. If you require additional
information or if the links do not work, please ask for clarification
before rating my answer and I will do my best to assist you.

Regards,
luciaphile-ga

---

Request for Answer Clarification by cvcope-ga on 20 Jan 2003 19:43 PST

I am not sure if my response you your answer was sent.  Please let me
know.  Thank you.

---

Clarification of Answer by luciaphile-ga on 20 Jan 2003 19:59 PST

Hi cvcope-ga, 
 
Did you need further clarification? I received the following:
"I am not sure if my response you your answer was sent.  Please let me
know.  Thank you."

Let me know if you'd like me to clarify further and if so, what
specifically you need addressed. Thanks!

Regards,
luciaphile-ga

---

Request for Answer Clarification by cvcope-ga on 20 Jan 2003 22:02 PST

Dear Lucia(phile):  First and foremost, thanks for answering my
question.  Unfortunately, there seems to be no one out there who takes
this matter seriously enough to do the research and determine the
actual shock transmission to a human's body/joints while running
wearing running shoes on different surfaces.

Mr. Cooper states concrete is 10 times as hard as asphalt and Dr.
Pagliano states that when grass rates a 9.5, asphalt rates a 6 and
concrete rates a 1.  While concrete obviously is harder that asphalt,
it is ludicrous to claim that magnitude of difference.  There is not
nearly as much difference as such statistics suggest – especially when
the significant cushioning provided by running shoes is factored in.

You referenced many interesting articles, just that none of them
provided specific data for the real shock transmission differential to
a runner's joints when he/she is wearing running shoes.  I appreciate
your credible endeavor in pursuit of a definitive answer, but I am
nonetheless disappointed with the lack of specific pertinent data.

Please comment if you wish.  Thanks again.

Richard Copeland
San Diego, CA

P.S.:  I am NOT trying to avoid paying for your answer.

---

Clarification of Answer by luciaphile-ga on 21 Jan 2003 09:14 PST

Hi cvcope-ga,

You wrote: “there seems to be no one out there who takes this matter
seriously enough to do the research and determine the actual shock
transmission to a human's body/joints while running wearing running
shoes on different surfaces.”

There is research in the medical literature on this topic. Because
your original question was specific to asphalt and concrete, I focused
on that. The Dixon article would be an excellent starting point for
you because it does address joint impacts on differing surfaces,
albeit not concrete.

I've got some more citations to some good scholarly articles, but
they're not available for free online. I can post those and give you
the PubMed abstracts, but because of copyright, I wouldn't be able to
post the articles themselves. Let me know if that's okay, in the
meantime, I'll see what else I can turn up for you.

Regards,
luciaphile

---

Request for Answer Clarification by cvcope-ga on 21 Jan 2003 10:03 PST

Dear Luciaphile:  I believe strongly, despite "conventional wisdom,"
there is not a SIGNIFICANT difference between asphalt and concrete in
terms of shock transmission for a runner wearing running shoes. 
You're an intelligent person, I'll bet you also suspect that to be the
case.  Is there any clear data that tells me I am wrong or that I am
right?  That is what I am trying to get clarified.  Thank you very
much.

Richard Copeland 
San Diego, CA

---

Clarification of Answer by luciaphile-ga on 22 Jan 2003 14:47 PST

Hi cvcope-ga,

I’ve done some additional research on your question. 

There have been studies done that touch your topic; nothing additional
that I can find, however, is specific to shock transmission for a shod
runner comparing asphalt and concrete.

Recent clinical studies, however, have looked at the kinematic
adjustments runners make. That is, how “runners adjust the stiffness
of their stance leg to accommodate surface stiffness during steady
state running.”

“Runners Adjust Leg Stiffnesss For Their First Step on a New Running
Surface,” by D.P. Ferris, K. Liang and C.T. Farley. Journal of
Biomechanics, vol. 32, issue 8, pp. 787-794, August 1999.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10433420&dopt=Abstract


What this suggests is that as runners adapt to whatever surface they
are running and lessening the ill effects that might otherwise be
expected from running on a harder surface, which would go to support
your hypothesis that there is no real difference.

“Impacts and Kinematic Adjustments During an Exhaustive Run,” by T.R.
Derrick, D. Dereu, and S.P. McLean. Medicine & Science in Sports &
Exercise, vol. 34, issue 6, pp. 998-1002, June 2002.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12048328&dopt=Abstract

The Dixon study (comparing artificial sports surfaces) offers the
conclusion that more research is needed before generalizations about
the effects on sports surfaces on “lower extremity kinematics.”

“Surface Effects on Ground Reaction Forces and Lower Extremity
Kinematics in Running," by Sharon J. Dixon, Andrew C. Collop and Mark
E. Batt. Medicine & Science in Sports & Exercise, vol. 32, issue 11,
November 2000, pp 1919-1926. PMID 11079523
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11079523&dopt=Abstract

I would also like to add that there are variables that need to be
taken into consideration—the quality and the running shoe for
instance.

Regards,
luciaphile-ga

Luciaphile has done an excellent job of responding to my question,
including providing the further clarifications I requested.  I am not
FULLY satisfied with the information provided - because, apparently,
no clinical researcher has actually done (or, at least, published into
the public domain) the data I seek and is NOT her/his fault.  She/he
would have had to personally have done the research in order to fully
answer the question.

My thanks to Luciaphile AND Google Answers for providing this valuable
service.

This article offers a rather limited perspective on the subject of
running on hard surfaces.  As world-class East African runners who cover
marathon distances on pavement prove, running technique matters.  In
fact, it is my feeling (I am a personal trainer holding several
certifications) that running technique is the most often ignored side of
this issue.

If you ask about ball-heel running on news:rec.running, you will find a
wealth of information, including links to Austin Gontang's
http://www.mindfulness.com, that suggest that any heel-first landing is
poor running form and nothing more.  Theories abound as to why so many
people land heel first, but much research shows that good runners either
land on the ball of their foot first or land midfoot (the entire foot
striking the ground at once).  The best book available on this subject
is by the well-known Dr. Michael Yessis - anyone discussing running
ought to have read this book, "Explosive Running."

The techniques Yessis and Gontang suggest can be learned by anyone; I am
puzzled as to why, if training and/or teaching is required to perform so
many of life's activities, running technique is completely ignored by
most people.  Learn to run properly and the surface on which you run
will matter very little.  I have, quite literally, run barefoot on
concrete with no ill effects.

Steve Freides, NSCA-CPT, RKC

Dear stevefreides-ga:  Thank you for the very intersting slant on my
question.  Of course, there is very little discussion on the 'style'
of running and that could make quite a lot of difference.  I'll look
at http://www.mindfulness.com.

Dick Copeland

There is a new type of running shoe that has a special polymer in the
midsole that automatically adjusts its degree of cushioning to the
level of impact.  the technology is described at www.powerbounce.us.