1. Are we born to run?
A biomechanical analysis of
barefoot/minimalist running and its
correlation to prevention of common
running injuries
Jason W. Harnett
2.
3.
4. Topics discussed
• Running in today’s society
• Evolution of running in humans
• Invention of the modern day running shoe
• Biomechanics of shod vs. barefoot/minimalist
running with analysis
• Common running injuries and causes
• Exercise prescriptions
• Case Study
• Culminating Activity
5. Running: todays society
• Today there are over 20 million runners in america that run
more than 100 times each year(SGMA, 2012)
• $2.46 billion spent on running shoes (SGMA, 2012)
• Over $1 billion dollars in charity raised (SGMA, 2012)
9. Environmental Shift
• Geologic evidence suggests a climate change over 2 million
years ago.
• Woodlands disappeared, savannahs resulted (Hazarika, 2007)
10. Diet Change
• Austrailopithecus were frugivorous (mainly ate fruit) and were
anatomically designed to walk and climb trees.
• Extinction due to environmental shift spawned the
evolvement of home erectus about 2 million years ago
(Hazarika, 2007).
• Homo erectus – first hominid anatomically designed to run.
• Primarily a meat eater
• First throwing weapon was the spear dating back 500,000 years
ago (Wilkens et al, 2012)
• Persistence hunter – chasing prey to the point of exhaustion
(Carrier, 1984)
20. Do shoes prevent injury?
• Van Gent study confirmed that injury rates have not seen any
significant improvement since the 1970s
• How running shoes are commonly prescribed
• Motion control
• Stability
• Cushioned
Marine Corps Study (Knapik, 2010)
No study has ever verified running shoes reduce injuries!
38. Torques on the Joints
• Forefoot runners knee torques are reduced in flexion, internal
rotation and varus (Kerrigan 2009, Standifird 2012)
• Decreased stride length = decreased hip adduction and
extension moment of knee (Heiderscheit 2011)
• Morley et al (2010) showed a decrease of >5 degrees in
calcaneal eversion range and velocity when forefoot striking
= decrease pronation.
39. Why the increased Pronation?
• Heel strikers pronate more because there is no musculature to
attenuate the forces.
• Forefoot strikers can control their pronation with the eccentric
contraction of the tibialis posterior along with the transfering
of forces to rotational motion of the talocrural joint.
• In other words, heel striking may cause excessive pronation
because impact forces cannot be transmitted through a
mobile ankle to the gastroc-soleus complex.
• Forces are transmitted by the subtalar joint, leading to rapid
pronation forces. (Morley, 2010)
43. How to tell is you are over
striding?
• Cadence = Amount of steps per minute
• Ideal number is 180 per minute
• Count number of steps in 6 seconds x 10
44. Video Analysis – (istherea properformtorunning?)
• Can you find 2 biomechanical deficiencies that may be contributing to this runners injuries?
45. Results
• Heel striker = increased transient force (more force in short
amount of time)
• Over strides = cadence of 160 steps per minute = increased
torque on joints
46. Common Running Injuries
• Plantar Fasciitis
• IT Band Syndrome
• Patellofemoral Pain
• Shin splints
• Stress Fractures
47. Plantar Fasciitis
• Plantar Fasciitis is caused
from weak intrinsic foot
musculature, placing
more stress on the
fascia, and flexibility
deficits in the posterior
calf. (Kibler, 1991)
• Minimal/Barefoot
strengthens intrinsic foot
musculature and
lengthens the posterior
calf muscles (Robbins,
1987)
48. IT Band Syndrome
• The development of
iliotibial band syndrome
appears to be related to
increased peak hip
adduction and knee
internal rotation.
(Noehren, 2006)
• According to
Heiderscheit (2011),
increased stride length
commonly seen in shod
runners increases both
hip adduction and
internal torque of the
knee.
49. Patella Femoral Pain
• Excessive impact shock during heel strike and at the
propulsion phase of running may contribute to an increased
risk of developing PFP (Thiis, 2008).
• Foot pronation causes a compensatory internal rotation of
the tibia and femur which upsets the patellofemoral
mechanism (Zappala, 1992).
50. Shin Splints
• According to Moen
(2011), excessive
pronation is linked
with medial tibial
stress syndrome.
• Shod and heel
striking increases
pronation motion
and velocity (Morley
et al. 2010)
51. Stress Fractures
• Studies suggest that
runners with higher
than normal tibial
acceleration and
vertical-force loading
rates are at increased
risk for tibial stress
fractures (Crowell,
2010)
• Barefoot/minimal
running reduces the
rate of loading
(Lieberman, 2011)
53. barefoot/minimalist is not for
everyone
• Surgeries that
have fusion
impair proper
mechanics of
foot
• Other major
orthopedic issues
• Overweight
• Impaired
sensation (ie
diabetics)
54. When to recommend change in
form or footwear?
When runners have tried everything and are still suffering from
injuries and other symptoms
When runner are serious about making a change…it requires
time and dedication
If patients are healthy and compliant, its easy to get injured….
What about people with flat feet and orthotics?....Robbins study
proves feet can be strengthened and arch heights increased.
55. Negative Effects
• There have been several studies that suggest running barefoot
or in minimalist can increase injury rate
• Jenkins 2011 meta-analysis study: Flawed studies, no formal
transitional training ever took place
• Runners were given minimalist shoes without assuring they
knew how to properly use them.
56. Transitioning Running Form
• Shoes have essentially weakened our feet by shortening the
Achilles and weakening the intrinsic and extrinsic foot muscles
and which possibly increases injury. (Robbins, 1987)
• 4x more likely to develop flat feet wearing shoes (Rao, 1992)
• Strengthening and stretching program must be implemented
before attempting to run with a new gait
=
57. How to transition
• Shod to minimal/barefoot……Start Slow!
• 4-6 month process
• Most people have been shod or heel strike runners their
entire life.
58. Transition Phase - Flexibility
• Assess motion at the ankle and forefoot
69. Group Case Study
• 34 year old male recreational runner whom recently began
training for Flying Pigs Marathon. He comes to you
complaining of anterior knee pain.
• Questions?
• Formulate groups and discuss questions you would ask, tests
and measures you would conduct, and exercise prescription
and education you would advise this particular patient.
71. Culminating Activity
• Let’s experience the difference!!
• Audience will run shod for 30 seconds on treadmill
• Then run barefoot for 30 seconds
• Note the differences you personally feel
72. Conclusion
• Scientists agree that we have evolved to run
• Shoes alter biomechanics of running
• Injury rates have not changed in over 30 years and no study
confirms shoes prevent injuries
• Heel striking increases rates of loading and over-striding,
which increases torques on joints
• Both shoes and heel striking encourage excessive pronation
• Shoes are proven to weaken intrinsic foot musculature and
shorten Achilles tendons
• There is enough anecdotal evidence to suggest these facts
may contribute to common overuse running injuries
•Could less be more?????
73. The Foot
• 26 bones
• 33 articulations
• Arch that 4 muscle
layers thick
• Several tendons and
ligaments
• “The human foot is a
masterpiece of
engineering and a
work of art.”
- Leonardo di Vinci
74. references• Kibler WB, Goldberg C, Chandler TJ. Functional biomechanical deficits in running athletes with plantar fasciitis. The American
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• Hazarika, Manji (16–30 June 2007). "Homo erectus/ergaster and Out of Africa: Recent Developments in Paleoanthropology
and Prehistoric Archaeology".
• Carrier DR."The Energetic Paradox of Human Running and Hominid Evolution". Current Anthropology, Vol.25, № 4, August-
October 1984
• Jayne Wilkins, Benjamin J. Schoville, Kyle S. Brown, and Michael Chazan. Evidence for Early Hafted Hunting Technology.
Science, 16 November 2012: 942-946
• Noehren B, Davis I, Hamill J. ASB clinical biomechanics award winner 2006 prospective study of the biomechanical factors
associated with iliotibial band syndrome. Clin Biomech (Bristol, Avon). 2007;22(9):951-6.
• Dixit, Sameer, et al. Management of patellofemoral pain syndrome. Am Fam Physician. 2007;75.2: 194-202.
• Thijs Y, De clercq D, Roosen P, Witvrouw E. Gait-related intrinsic risk factors for patellofemoral pain in novice recreational
runners. Br J Sports Med. 2008;42(6):466-71.
• Zappala FG, Taffel CB, Scuderi GR. Rehabilitation of patellofemoral joint disorders. Orthop Clin North Am. 1992;23:555–66.
• Moen MH, Tol JL, Weir A, et al. Medial tibial stress syndrome: a critical review. Sports Med. 2009; 39:523Y46.
• Crowell HP, Milner CE, Hamill J, Davis IS. Reducing impact loading during running with the use of real-time visual feedback. J
Orthop Sports Phys Ther. 2010;40(4):206-13.
• Heiderscheit BC, Chumanov ES, Michalski MP, Wille CM, Ryan MB. Effects of step rate manipulation on joint mechanics
during running. Med Sci Sports Exerc. 2011;43(2):296-302.
• SGMA. Sporting Goods Manufacturers Association. 2012 SGMA Sports & Fitness Participation Topline Report, based on
participation numbers in the U.S. projected from online interviews of a nationwide sample. To obtain information on any of
the SGMA products or services, email: info@sgma.com, phone (301) 495-6322, or go to www.sgma.com
• Van gent RN, Siem D, Van middelkoop M, Van os AG, Bierma-zeinstra SM, Koes BW. Incidence and determinants of lower
extremity running injuries in long distance runners: a systematic review. Br J Sports Med. 2007;41(8):469-80.
• Hasegawa H, Yamauchi T, Kraemer WJ. Foot strike patterns of runners at the 15-km point during an elite-level half marathon.
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75. References
• Lohman, E. B., Sackiriyas, K. S. B., Swen, B. W. (2011). A comparison of the spatiotemporal parameters, kinematics,
and biomechanics between shod, unshod, and minimally supported running as compared to walking. Physical
Therapy in Sport, 12, 151-163.
• Lieberman et al. (2011). Foot strike patterns and collision forces in habitually barefoot versus shod runners.
Nature, 463, 7280.
• Jenkins, D. W., & Cauthon, D. J. (2011). Barefoot running claims and controversies: A review of the literature.
Journal of the American Podiatric Medical Association, 101(3), 231-246.
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26, 78-83.
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reduction effectiveness of assigning running shoes based on plantar shape in Marine Corps basic training. Am J
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Editor's Notes
Barefoot running has been highly debated hot topic as of late in the biomechanical and clinical fields….i but I think as Pts in the outpatient, where you will generally see overuse running injuries, its important to understand the current literature and its clinical implications…so why is this topic currently so popular…
Why is the topic so popular today…..
Another reason the topic is so popular is from the marketing efforts of companies like vibram five fingers, im sure you may have seen a pair or two of these before….they are marketing the minimalist concept…everyone should run more barefoot, so where are shoes with toes….But is there any real truth behind this craze, or is it just another fad…..we will investigate the research….
One of the fastest growing sports in america today….20 million run at least 3x per week…and 50 million run at least 1x per year…for a charity race or other even….shoes sales reached an alltimehight….6% increase from previous year….charity…top 7 charities combined…
Health benefits
So if so many people get injured running, it begs the question of whether or not we are supposed to be performing this activity….
About 2 million years ago, there was an environmental shift in Africa that caused the loss of all the woodlands starting disappearing and the savannahs started growing…new food started appearing, and that of course was meat….there was a wide variety of ungulates on the grassland, and in order to hunt human being evolved to run….what we are good at is making animals run at speeds that make them gallop….and quadrupeds do not have the ability to pant as they run, therefore they can overheat very quickly….so if you can make an animal run for 15 minutes or so, you have got dinner…this was called persistence hunting…there is no evidence of any sort of weapon until1.5 million years ago…so for half a million years are are hunting prey with no weapons….so this is how humans survived…there is even evidence comparing the last walking man…austrailopithicus (lucy) and the first running man (homo erectus)…anatomical differences…(nuchal ligament, narrow thorax, broader articulation surfaces, shorter femoral necks….so clearly we evolved to perform this activity….so the question is how are human beings running millions of years without any PTs, podiatrists, orthotics, or even shoes for that matter (because evidence of the first shoe ever used by mankind was not until only 10,000 years ago) and remain healthy enough to sustain an entire species….and why today are so many of us getting injured doing the exact same activity we no do for health and recreation? Its almost as if a fish getting a fin injury or a bird getting a wing injury…its counterintuitive….So maybe we are doing it wrong…what is different today than back then?
Our old way of survival was to climb trees for nuts and berries, we then evolved to chasing down animals for survival due to the climate shift….several anatomical diffrences between the first walking man austrailopithicus and homo erectus – the first known runner….this along with the fact that the first projectile weapon was not used until only 17,00 years ago
Our ancestors over 2 million years ago were able to run with no PTs, podiatrists, orthotics or even shoes….it asks the question…could it be the shoes?...spike lee its gotta be the shoes….
There is evidence that shows the first shoes utilized by mankind wasalomost 20,000 years ago….basic function was basically to protect the bottom of your foot….if you think about clothing….there is no other article that offers muscular support…..
This is where I think the downfall of running came from – it was the first shoe to offer any heel cushioning….phil knight was the shoes representative in the US….he later founded nike
This is what running shoes have evolved too…something that is supposedt to be protective…to something that looks like this……this thing is a tank….it has an elevated cushioned heel, stiff heel counter, arch support, high medial mid sole density anti torsion and pronation devices, all the bells and whistles – basically an orthotic device..and it weighs over a poundBut are all these bells and whistles helping prevent running injuries….Recent study by van gent et al from 2007…meta analysis study…confirmed 79% of runner get injured – when compared to another study iSo maybe the more intervention with something…the more we monkey around with the human me
I will say that it is very difficult to confirm the exact rates of injury…so it is hard to make this specific correlationSo if what is the difference in running with shoes and barefoot or minimalist?I guess the best way to investigate is to watch people run….
Elevated Cushioning has allowed for runner to land on their heels…which as a result lead to longer strides, but this may not be a good thing….but if you take someone out of their shoes, which we will see in a minute, they will naturally come off their heels, why do you think that is?You are shielded
You are shielded from the truth….the truth of pain
Biomechanics is a measure of the forces, both internal and external, applied to the body during movement
So maybe its not the shoes….its how we land….much more difficult to forefoot strike in shoes, bc you do not have that tactile feedback
Increased stride length = landing farther in front of body = longer moment arm = more torque on the jointsHold weight out in front of you, now bring it in, which is harder on shoulder joint = same forces on knee and hip during overstriding
An average 54% increase in the hip internal rotation torque, a 36% increase in knee flexion torque, and a 38% increase in knee varus torque were measured when running in running shoes compared with barefoot.
Heel strikers have a higher incidence of pronation due to pronatory whip
