Article

A Test of the Metabolic Cost of Cushioning Hypothesis during Unshod and Shod Running

Medicine and science in sports and exercise (Impact Factor: 3.98). 02/2014; 46(2):324-329. DOI: 10.1249/MSS.0b013e3182a63b81
Source: PubMed

ABSTRACT

This study aimed to investigate the effects of surface and shoe cushioning on the metabolic cost of running. In running, the leg muscles generate force to cushion the impact with the ground. External cushioning (surfaces or shoes) may reduce the muscular effort needed for cushioning and thus reduce metabolic cost. Our primary hypothesis was that the metabolic cost of unshod running would decrease with a more cushioned running surface. We also hypothesized that because of the counteracting effects of shoe cushioning and mass, unshod running on a hard surface would have approximately the same metabolic cost as running in lightweight, cushioned shoes.
To test these hypotheses, we attached 10- and 20-mm-thick slats of the same foam cushioning used in running shoe midsoles to the belt of a treadmill that had a rigid deck. Twelve subjects who preferred a midfoot strike pattern and had substantial barefoot/minimalist running experience ran without shoes on the normal treadmill belt and on each thickness of foam. They also ran with lightweight, cushioned shoes on the normal belt. We collected V˙O2 and V˙CO2 to calculate the metabolic power demand and used a repeated-measures ANOVA to compare between conditions.
Compared to running unshod on the normal belt, running unshod on the 10-mm-thick foam required 1.63% ± 0.67% (mean ± SD) less metabolic power (P = 0.034) but running on the 20-mm-thick foam had no significant metabolic effect. Running with and without shoes on the normal belt had similar metabolic power demands, likely because the beneficial energetic effects of cushioning counterbalanced the detrimental effects of shoe mass.
On average, surface and shoe cushioning reduce the metabolic power required for submaximal running.

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Available from: Rodger Kram, Jan 24, 2014
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    • "Indirect evidence suggests that the lack of cushioning and arch support in minimalist shoes also improves running economy, independent of shoe mass, by allowing more elastic energy storage and release in the lower extremities (Perl et al., 2012). However, cushioning in shoes helps to reduce the muscular effort needed to cushion impacts with the ground; thus, reducing metabolic cost (Franz et al., 2012; Tung, Franz, & Kram, 2014). It is unclear whether "
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    No preview · Article · Apr 2015 · Journal of Biomechanics
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    • "Many biomechanical studies have shown that individuals respond to a given intervention in a subject-dependent way with the result that the very same intervention can be beneficial for one person but not for another. Subject-dependent responses were reported with respect to footwear (Erhart et al., 2008), running surfaces (Tung et al., 2014), orthotics (Nester et al., 2003), and loading perturbations (James et al., 2014). Thus, from an analytical point of view, the task of predicting the " right " intervention is all but trivial. "
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