I paladini delle scarpe moderne
Very few scientists or health professionals still defend modern running shoes (big bulky ones). However, a one of them is a very tenacious, but good expert in the subject; Kevin A. Kirby, Podiatrist (Adjunct Associate Professor, Department of Applied Biomechanics, California School of Podiatric Medicine) keeps exposing himself as a fervent modern running shoes advocate. I know Kevin from blogs like Podiatry Arena and Podiatry Today, and I have to say that his elaborate knowledge on questions surrounding running shoes make him a great debater. I don't agree with some of his opinions but I respect the man and the ideas he scientifically defends.
Kevin recently published an article on http://www.podiatrytoday.com/barefoot-versus-shod-running-which-best and already had exposed "the 10 facts that barefoot running defenders never speak about". Here are our answers in blue!
Kevin A. Kirby: Here are some facts that the barefoot running advocates seem to never mention:
1. All the current world records in track, road racing and cross-country were set, not barefoot, but in shoes.
A : With very minimalist shoes for 90% of them. (zero-drop for spikes, very light and no support for all these shoes)
2. No international marathon has been won by a barefoot runner (running the whole race barefoot) for the last 50 years.
A: That's a proof that modern men are completely addicted to shoes and to a certain degree of protection… it’s not the proof that it’s better (Same parallel with obesity... normality and generality don't mean better... 60% of north-Americans are overweight... and it isn't something I recommend.)
3. "Minimalist shoes" are nothing new and they have been continuously available in running shoe stores for the past 40 years. They were called "racing flats" for the past 40 years.
A: Yes, but the running shoe retailers recommend this type of shoe only to the skinny fast young runners… 3% of the runners and 3% of sales up until 2 years ago. Good thing that this new trend of "Minimalism" is changing minds, and is allowing for a better open-mindedness from retailers!
4. Abebe Bikila won the 1964 Tokyo Olympic Marathon, breaking the world record in a time of 2:12:11, while in shoes, running 7 seconds per mile faster than he had in the 1960 Rome Olympic Marathon where he ran barefoot.
A: Indeed, and 4 years later he was injured (stress fracture caused by his new heel strike pattern induced by the shoes? Don’t know… just guessing :) ) . You can compare track performance… but not different marathons (environmental conditions, hills, …).
5. Zola Budd, who broke the women’s 5,000 meter world record while barefoot now prefers shoes saying: “: “I no longer run barefoot. As I got older, I had injuries to my hamstring. I found that wearing shoes gives me more support and protection from injuries.”
A: Personal feeling and maybe misconception… Some runners successfully switched to barefoot running for exactly the same reasons! Do you think that shoes decrease mechanical stress on the hamstring? Do you think that big bulky shoes decrease the stress on any other part of the body than the foot and the lower part of the leg?
6. Split-toe, thin-soled running shoes, such as the Vibram FiveFinger are nothing new. The 1951 Boston Marathon was won by a Japanese runner, Shigeki Tanaka, wearing a split-toe, thin-soled running made by Onitsuka Tiger (now Asics).
A: No comment… what’s the problem?
7. Six scientific research studies published in peer-reviewed journals show that barefoot running increases the vertical loading rate -VLR- compared to shod running (Dickinson, 1985; Komi, 1987; Lees 1988; Oakley, 1988; DeClercq, 1994; DeWit, 2000).
A: You forgot Cole-1995, De Koning-1993, McCarthy-2011(UP), O’Leary-2008 for your assumption … but also other studies saying the opposite (Lieberman 2010, Divert 2004, Hamill 2011). Most of the studies showing an increase of VLR are done with runners used to shod running...suddenly running barefoot... few trials on a short runway of 20 to 30m... with often no change (or not enough) in their biomechanics (most of the time, these runners, keep heel striking, voluntarily or not). Runners used to run barefoot have clearly less VLR (Lieberman 2010, Squadrone-2009).
8. Barefoot running causes increased tibial acceleration (McNair PJ, Marshall RN: Kinematic and kinetic parameters associated with running in different shoes. Br J Sp Med, 28:256-260, 1994).
A: One more time, a single study with 10 people used to shod running… with small and subtle kinematic differences between barefoot and shod conditions. Why not to name 'Shorten 2002' (review) or 'Kerrigan 2009' (shoes increase joint torques at the knee and hips) or 'Braunstein 2010, Shakoor 2006, Bergmann 2010' (shoes increase stress on the knee) or other studies using extensiometers, intra-articular chips, accelerometers,… and showing different results (Rethnam 2011, Hamill 2011, Lieberman 2010, Bergmann 2010, Divert 2004, 1996 Hennig).
9. The world’s leading researcher in running biomechanics and running shoe biomechanics, Dr. Benno Nigg, did a prospective study that found no significant differences in frequency of running injuries between subjects with high-, medium-, or low-impact peaks and that subjects with higher loading rates had significantly fewer running-related injuries when compared to subjects with lower loading rates (Nigg BM. Impact forces in running. Current Opinion in Orthopedics, 8(6):43-47, 1997). Dr. Nigg further claims that “Currently, there is no conclusive evidence that impact forces during heel-toe running are responsible for development of running-related injuries.” (Nigg BM: Biomechanics of Sports Shoes. University of Calgary, Calgary, 2010. p. 32.)
A: I agree with most of Nigg's statement… but still we need to consider all the other studies on that topic, especially those made after the publication of his book (2011-Zadpoor, 2010-Davis(UP)… and 2006-Millner, 2006-Dixon, 2005-Zifchock, 2005-Divert, 2005-Dallam, 2005-Hreljac, 2004-Arendse, 2003-Mercer, 2000-Hreljac, 2000-Razeghi). Just for your information, the conclusion of Dr Nigg is also suggesting the non-effect of shoe cushioning to prevent injuries.
10. Barefoot running increases internal tibial rotation vs shod running, meaning that rearfoot pronation and injuries associated with excessive rearfoot pronation may be increased in barefoot running (Eslami M, Damavandi M, Allard P: Foot joints and tibial kinematic coupling patterns during stance phase of barefoot versus shod running. J Biomech, 39:S183, 2006. Fukano M, Nagano Y, Ida H, Fukubayashi T: Change in tibial rotation of barefoot versus shod running. Footwear Science, 1:19-23, 2009.)
A: Pure correlation... not causation! Pronation and internal tibial rotation are not clear causes of injuries (2009(RS)-Barton, 2009(SR)-Zammit, 2008-Grau, 2008-Donoghue, 2008-Srcevic, 2007-Wilson, 2006-Cheung, 2005(R)-Hreljac, 2005(R)-Knutson, 2002(R)-Gurney, 2001-Nigg, 2000-Hreljac, 2000-Razegi, 1998-Hintermann, 1997-Wen, 1997-Stergiou, 1994-Hintermann). Some authors think that shoes increase pronation (Stacoff-2001, Hamill-1992, Heil-1999) and can change the knee alignment (Radzimski(RS) 2011, Chen 2010, Kerrigan 2009, Burkett 1985, Chen 2010)
11. There is not one shred of scientific research that shows that running barefoot or running in minimalist shoes reduces the risk of injury. However, the rate of stress fractures in the metatarsals is alarming of those runners who switch to running barefoot or running in “minimalist shoes”, such as the Vibram FiveFingers.
A: Why alarming? Anecdotic cases without scientific evidence (except a study on 2 subjects: Giuliani 2011) are used to draw attention away from the fact that promoting modern running technologic and maximalist shoes (90% of the current market) is not supported by any scientific evidence showing their benefits in preventing running injuries. That being said, I am convinced that a too quick transition towards minimalism or barefoot running can be harmful for tissues weakened by frequent wearing of modern maximalist running shoes.
Kevin A. Kirby, DPM Adjunct Associate Professor Department of Applied Biomechanics California School of Podiatric Medicine A: Blaise Dubois, PT, MSc Candidate, RCAMT, SPD