title: Perceiving slipperiness and grip: A meaningful relationship of the shoe-ground interface.
abstract: The present study investigated the relationship between objective measurements of the available (CoFA), the utilized (CoFU) coefficient of friction and subjective perception of grip or slipperiness. It was hypothesized that significant correlations exist between the perception of grip or slip and the CoF during sports movement and that a minimum CoF was needed to ensure an optimal grip/slipperiness perception. Eighteen healthy active females performed forward and backward cutting tasks onto a forceplate. Six shoes and two floors were used to induce different grip conditions. Subjective ratings and CoFUwere assessed for each shoe-floor combination, and mechanical CoFAwas also measured in a specific test bed. Significant relationships (p<0.001) were found between grip, slipperiness ratings or CoFAwith the CoFU(r=0.98, r=-0.97, r=0.88, respectively). Individual sensory thresholds of the minimum required CoFUwere also determined using probit models between the CoFUand the grip acceptability. The mean threshold defined in the present study was 0.70±0.11. This meant that below this threshold, the grip perception was not acceptable, whereas above this threshold, the grip was felt good enough to perform the task. In conclusion, strong relationships between subjective perceptions and objective measurements of friction were found in sports-like movements. Moreover, a minimum friction requirement was defined for indoor dry shoe-floor conditions. The present study gives new insights of the shoe-floor interaction and outlines friction requirements for the manufacturers of sports floor or footwear.
authors.affiliation: Decathlon SportsLab, Department of Movement Sciences, 4 boulevard de Mons, Villeneuve d'Ascq, F-59650, France. Electronic address: cedric.morio@hotmail.fr.
authors.forename: Cédric
authors.initials: C
authors.lastname: Morio
authors.affiliation: Universités de Lille, CNRS, CHU Lille, UMR 9193 - SCALab, Sciences Cognitives et Sciences Affectives, F-59000 Lille, France.
authors.forename: Aurore
authors.initials: A
authors.lastname: Bourrelly
authors.affiliation: Decathlon SportsLab, Department of Movement Sciences, 4 boulevard de Mons, Villeneuve d'Ascq, F-59650, France.
authors.forename: Lise
authors.initials: L
authors.lastname: Sissler
authors.affiliation: Decathlon SportsLab, Department of Movement Sciences, 4 boulevard de Mons, Villeneuve d'Ascq, F-59650, France.
authors.forename: Nils
authors.initials: N
authors.lastname: Gueguen
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control*; D000328:Adult; D005260:Female; D005430:Floors and Floorcoverings; D017276:Friction; D005684:Gait; D006801:Humans; D010465:Perception; D012016:Reference Values; D040242:Risk Reduction Behavior; D012775:Shoes
keywords: Footwear; Friction coefficient; Perception; Subjective rating; Traction