Benno M. Nigg
Clinical Journal of Sport Medicine. 11:2-9.2001


Jogging and Running is a favourite and easy form of exercise most people resort to when commencing an exercise routine. Unfortunately 37-56% of individuals who begin running become injured within the 1st year (1-5). It is speculated that most running injuries can be caused by overtraining, excessive impact forces and excessive Pronation. Pronation is a natural movement of the foot that occurs during foot landing while running or walking.The purpose of this article is to discuss the possible connection between the amount of impact forces and foot pronation and the development of running related injuries. Firstly, let’s define a few terms: 1. ‘Impact Forces’ force or shock applied over a short time period and repeatedly. Running is an excellent example of force repeatedly occurring as the foot hits the ground and impact is felt by the muscles, bones, tendons, joint and nerves of the lower body. There is a thought that this type of force has a greater effect than a lower force applied over a longer period of time. I want to define one more term that will connect the impact (pardon the pun) to the relevance of this paper and highlight THI’s approach to managing sport injuries of the lower limb that exists in not only runners but basketball, soccer, football and tennis players (pivot sport athletes). As you may recall ‘Pronation’ or what local folks would call “flat foot” is the natural movement of the foot that occurs during foot landing while running or walking….NATURAL POSITION of the foot ladies and gentlemen. Not sure when this happened in the manual therapy/sport world that pronation or overpronation become a disease. ‘Overpronation’ by the way is simply defined as excessive inward rolling of the foot as the their is contact to the ground with walking and especially with running. The purpose of this paper is to introduce, discuss and debunk the idea that devices to correct overpronation while running is not actually doing what we once thought. Interestingly, the author attempts to introduce a new idea/concept as to what happens when the foot hits the ground while runners run and if this causes an increase in injury….so if you run or own a clinic selling these devices you may want to continue reading or delete this blog real quick!


The author, Dr. Benno provided a concise review of the literature indicating a common BELIEF, yes BELIEF that shoes, shoe surface and shoe inserts
can influence foot pronation and subsequently causing injuries. I will not attempt to paraphrase what the good doctor said let me just drop it in right here:
“the concepts of cushioning and movement control were developed as well as concepts to correct harmful impact forces and pronation with magical and OVERLY PRICED items such as running shoes, shoe inserts (orthotics aka the money maker) and sport surface designs. Interestingly, multiple studies back in the day of when this paper was written (2001) and to present day have challenged, mocked and have laughed at the association between impact forces, foot pronation and running injuries.


*Impact forces in heel toe running are forced resulting from collision of the heel with the ground.
*Despite what the shoe salesman at your local athletic store tells you about the OVER PRICED shoes and their features to reduce impact forces such as

  • hardness of the running shoe sole
  • shock absorbing material

Are all false and BULL SHIT. According to Dr. Benno hardness of a running shoe midsole minimally influenced the amount of impact forces during running. Dr. B also noted that the incidence of stress fractures specifically were not reduced due to shock absorbing insoles. Let’s upset you some more, Dr. B also found 4 studies with unexpected results indicating that runners did not show higher incidence of osteoarthritis than nonrunners. That is the total opposite of what Sally The Physio has been saying for years! Also, are you sitting? I really think you should sit for this one “ running on hard surfaces did not result in an increase of running injuries if compared with running on softer surfaces.” This is TOTAL opposite of what I was taught by ALL my exercise prescription instructors and even some of chiropractic instructors.

Serious question: Why the fuck was being taught such bullshit that wasn’t even true?
Honest answer: our education system is lazy as fuck and it is easy to give an answer of simplicity then objectivity.
Here is what Dr. B says about impact forces and why we need them…in certain parts of our body.

*Bone… The skeletal system…the hard things that keep our body up, love and need impact forces to build density and ultimate strength. “Impact stumli have been shown to improve bone integrity.” Says Dr. B. Early findings from the studies Dr. B has examined revealed that cartilage is not a fan of impact forces….specifically “high loading rates: high loading rates is exactly what it sounds like load of impact at a high frequency, showed an increase of cartilage damage in impact experiments compared with low loading rates. BUT conflicting findings examining high performance female gymnasts showed an increase in spine skeletal mass. So what exactly does this mean?! Basically impact activities actually has benefit to our body specifically our bones…we know this already because women who are premenopausal we (health care providers) encourage them to perform impact exercise protocols to support bone mineral density that naturally declines due to the hormonal changes of menopause. Also, “the locomotor system chooses a strategy to keep the skeletal movement in a constant path when force is applied on it.” According to Dr. Benno “The neuromuscular is programmed to avoid any deviation from this path. Thus, appropriate muscles will be activated if any intervention tries to produce a different skeletal movement. An optimal shoe, insert or orthotic would minimize additional (not task related muscle work.” So here is the the MILLION DOLLAR QUESTION: Are wearing orthotics good or bad or do they promote a lazy neuromusculoskeletal system? The answer is ABSOLUTELY. The insert is replacing the job of structures in the body to absorb force (ligaments, joints, tendons, and muscles). So if you replace it with an insert those above structures go out to lunch/coffee break/ vacation and then when you call on said structures to say um move they say “fuck off go ask the orthotic to make you move! And thus an injury occurs cause you are asking structures who have been dormant to generate power or simply move.

TAKE HOME MESSAGE: Train. Train Everyday. Train ALL parts of your body including the joints, ligaments, tendons, nerves and muscles of your feet EVERY DAMN DAY!

For the promotion of Health, Fitness and well being.

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