title: Football playing surface and shoe design affect rotational traction.
abstract: BACKGROUND
  High rotational traction between football shoes and the playing surface may be a potential mechanism of injury for The abstract goes here and covers two columns. the lower extremity.
  
  
  OBJECTIVE
  Rotational traction at the shoe-surface interface depends on shoe design and surface type.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  A mobile testing apparatus with a compliant ankle was used to apply rotations and measure the torque at the shoe-surface interface. The mechanical surrogate was used to compare 5 football cleat patterns (total of 10 shoe models) and 4 football surfaces (FieldTurf, AstroPlay, and 2 natural grass systems) on site at actual surface installations.
  
  
  RESULTS
  Both artificial surfaces yielded significantly higher peak torque and rotational stiffness than the natural grass surfaces. The only cleat pattern that produced a peak torque significantly different than all others was the turf-style cleat, and it yielded the lowest torque. The model of shoe had a significant effect on rotational stiffness.
  
  
  CONCLUSIONS
  The infill artificial surfaces in this study exhibited greater rotational traction characteristics than natural grass. The cleat pattern did not predetermine a shoe's peak torque or rotational stiffness. A potential shoe design factor that may influence rotational stiffness is the material(s) used to construct the shoe's upper.
  
  
  CONCLUSIONS
  The study provides data on the rotational traction of shoe-surface interfaces currently employed in football. As football shoe and surface designs continue to be updated, new evaluations of their performance must be assessed under simulated loading conditions to ensure that player performance needs are met while minimizing injury risk.
authors.affiliation: Orthopaedic Biomechanics Laboratories, College of Osteopathic Medicine, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Villwock
authors.forename: Eric G
authors.initials: EG
authors.lastname: Meyer
authors.forename: John W
authors.initials: JW
authors.lastname: Powell
authors.forename: Amy J
authors.initials: AJ
authors.lastname: Fouty
authors.forename: Roger C
authors.initials: RC
authors.lastname: Haut
mesh_terms: D016512:Ankle Injuries / Q000209:etiology* / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D005538:Football / Q000293:injuries*; D017276:Friction; D006801:Humans; D012399:Rotation; D012775:Shoes / Q000009:adverse effects*; D013499:Surface Properties; D019415:Torque