I have no doubt about the importance of plantar sensory input has on normal gait, balance and postural stability; having spent many years looking at the impacts of diabetes and what the sensory neuropathy does to gait and balance. What I do have doubts about, and will address this in greater detail in a future post, is the role that footwear, especially softer footwear, has on attenuating that sensory input. The rhetoric and propaganda is all around that we need to feel the ground to have those appropriate sensations for normal function and postural stability. However, simply stating that its important and then wishing it was true does not make it true and is a logical fallacy. The fan boys go as far as saying we need barefoot or minimalism to improve “proprioception”. I am not sure how that actually is supposed to work as there are no proprioceptive sensors in the skin on the sole of the foot….but will leave ridiculing that woo to another day when I feel better! Which brings me to this study that appeared a few weeks ago:
Minimalist, standard and no footwear on static and dynamic postural stability following jump landing
Astrid Zech, Andreas Argubi-Wollesen & Anna-Lina Rahlf
European Journal of Sport Science Published online: 10 Jul 2014
In recreational sports, uncushioned, light-weight and minimalist shoes are increasingly used to imitate barefoot situations. Uncertainty exists whether these shoes provide sufficient stability during challenging movements. In this randomised crossover study, 35 healthy distance runners performed jump landing stabilisation and single-leg stance tests on a force plate, using four conditions in random order: barefoot, uncushioned minimalist shoes, cushioned ultraflexible shoes and standard running shoes. Ground reaction force (GRF) and centre of pressure (COP) data were used to determine unilateral jump landing stabilisation time and COP sway velocity during single-leg stance. Repeated measures analysis of variance revealed significant footwear interactions for medial–lateral (p < 0.001) and anterior–posterior COP sway velocity during standing (p < 0.001). The barefoot condition produced significantly greater postural sway velocities (p < 0.001) compared to all footwear conditions. No significant effects were found for jump landing stabilisation time. In conclusion, the results of this study indicate that increased shoe flexibility and reduced sole support have no, or only minor influence on static and dynamic postural control, and therefore, may not increase the risk of traumatic events during sports activities. However, barefoot conditions should be considered carefully when adequate postural control is needed.
These authors wanted to look at the effects of minimalist shoes on postural stability. They recruited 35 distance runners and tested them in 4 conditions: barefoot; minimalist shoes (Leguano); Nike Free 3.0; Asics GT-2160; and then performed jumping and single leg standing tasks while kinematic and kinetic data was collected.
Nothing in the methods and the analysis jumps out at me as being problematic.
Without getting in the complexity of the reported findings and details of the measurements (they are in the full publication), what the authors found was clear: “The major finding of this study is that, compared to barefoot conditions, shoes improve postural control during single-leg stance in distance runners” and “Our findings suggest that footwear is beneficial for the maintenance of static balance but has no noticeable impact on dynamic postural stability” and “Therefore, it is concluded that shoe flexibility and cushioning has little or no impact on postural stability.”
In other words, being able to “feel” the ground more in the barefoot or minimalist condition did not improve postural stability (or “proprioception” if you want to believe in that woo) compared to having a softer shoe on the foot. Which is the opposite of what the propaganda, rhetoric and wishful thinking predicted.
As always, I go where the evidence takes me until convinced otherwise and this study tells me that barefoot or minimalist shoes do not enhance postural stability due to being able to “feel” the ground more.
Zech, A., Argubi-Wollesen, A., & Rahlf, A. (2014). Minimalist, standard and no footwear on static and dynamic postural stability following jump landing European Journal of Sport Science, 1-7 DOI: 10.1080/17461391.2014.936322