Impact forces between barefoot and shod running

I have been around this stump many a time and here we go again:

Meredith, K; Castle, B; Hines, D; Oelkers, N; Peters, J; Reyes, N; Conti, C; Pollard, C; and Witzke, K
International Journal of Exercise Science: Conference Proceedings: Vol. 8: Iss. 3, Article 13. 2015
Recently, barefoot running versus shod running (with shoes) has received a significant amount of attention due to variances found in ground reaction forces (GRF) between the two conditions. However, a recent meta-analysis states that there is limited research showing biomechanical differences between barefoot versus shod running. Others believe running without shoes produces lower GRFs and result in less traumatic impact and stress on the joints of the lower extremity. Analyzing and understanding these GRF differences can help researchers, physical trainers, athletes, etc., to recognize potential benefits and risks that different running styles have on the human body.
PURPOSE: The purpose of this study was to determine the differences in GRFs between barefoot and shod running, focusing on the peak vertical impact forces (first peak) during running.
METHODS: Subjects included 7 female and 5 male physically active participants between the ages of 21-36y. Each subject was instructed to jog at a medium-fast, constant, self-selected pace approximately 6 m over two force plates (AMTI, 1500 Hz) while GRF’s were recorded for the left foot. Peak vertical impact force for two to three trials were averaged for each condition, barefoot and while wearing the subject’s own running shoes. A dependent t-test (SPSS v. 22) was used to test mean differences between conditions at p0.05).
CONCLUSION: This study failed to show a significant difference between peak vertical impact forces during barefoot and shod running. Future research is needed for this study with a larger sample size, perhaps looking at the differences in GRFs in subjects who habitually run barefoot versus those who do not.

I have no more information on this study than what is in the above abstract as it was presented at a conference, so a detailed analysis of the methods is not possible. Nothing in what is stated in the methods and analysis above seems problematic, but it does bear mentioning that this was an acute intervention and the results may or may not be different if the participants went through a proper period of adaptation to the two conditions.

The rhetoric and propaganda was, and to some extent still is, that barefoot or minimalist running results in less impacts and therefore is better. The above study shows that its not. This is also, however, based on the premise that impacts are even a risk factor for running injuries. As I keep pointing out, the evidence for that is far from compelling and there is even evidence that there is a less of a risk of injury if the impact forces are greater.

This study is also pretty consistent with all the other studies that I have reviewed here:
Impact Reduction Through Changing to Midfoot Strike Pattern vs Low Drop Footwear
Tibial strain and barefoot running
Increased Lower Limb Loading with use of Minimalist Running Shoes
Barefoot vs shod running: Effects on tibia loads
Rearfoot and Midfoot/Forefoot Impacts in Habitually Shod Runners
Review of Lieberman et al’s (2010) paper in Nature on Barefoot Running

It is really a bit difficult to get excited about this paper as the issue has been dealt with many times and relitigating the same old issues can get a bit depressing and boring.

As always, I go where the evidence takes me until convinced otherwise ….and this study further confirms that all the rhetoric and propaganda that has been spun in crankosphere blogosphere is yet again not supported by the evidence.

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5 Responses to Impact forces between barefoot and shod running

  1. Roman R. April 12, 2015 at 7:07 am #

    Question is, are they talking about barefoot running or forefoot running barefoot? The differences in the impact peak are based on the way the foot hits the ground, not necessarly the footwear. Don’t know if they imply that barefoot running means forefoot striking and shod running rearfoot striking.
    I think the method with only 2-3 trials is quite vulnerable to gait variations. Additionally I would find it hard to reproduce my selfselected running speed over only 6m after changing footwaer. Also having to hit a target (force plate) can change your strike pattern dramatically.
    In my opinion quite considerable limitations….

    • Craig Payne April 12, 2015 at 7:25 am #

      Don’t know. We do not know what the trial to trial variability was. All we know is what is in the abstract.

  2. Roman R. April 12, 2015 at 9:20 am #

    True. Just a little disturbed by the 2 to 3 trial average. Seems to me kind of random. Like if they looked at the impact curve and said: “yeah those two look fine. Lets take them. The third one looks kinda messed up” or “the first two trials look similar we don’t need a third one”.
    All speculation, but a little odd, don’t you think?

  3. Jeff April 13, 2015 at 9:37 pm #

    The study and your corresponding review seem utterly bent on finding a result before any “research” was done. Barefoot running is a learned skill that 99% of people do not possess. Running properly with a soft forefoot strike, (the thing that nets a runner a low grf value, and prevents injury) while running barefoot or not takes time to accomplish. Running barefoot consistantly aids in learning a proper run form that nets lower grf values. Asking a bunch of general untrained runners, with their heal strike run form, to test in their shoes and then barefoot is not going to give you anything close to accurate results. Try researching the benifits of barefoot running a little more before brandishing an ignorant opinion based on half assed research.

    • Craig Payne April 14, 2015 at 1:56 am #

      All 12 of the formal systematic reviews of all the evidence has concluded that there are no systematic benefits of barefoot running over shod running. None of what you are saying is either supported by the evidence or is contradicted by the evidence. I think I will stick to what the actual scientific evidence actually says.

      The interest in barefoot/minimalism has declined; the sales of minimalist running shoes have dropped to a minuscule share of the market. There is a reason for that.

      BTW, what has lower grf values got to do with injures? And even if you do reduce the grf by changing gait, those forces have to go somewhere else that just increases the risk for injury in those tissues. Stick to the evidence rather than use the wishful thinking fallacy.

      Also, the research that I recently reviewed that looked at doing what you suggest actually showed that the outcome was a less economical way to run. No thanks. Again, I prefer to stick to what the science says.

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