title: Shoe drop has opposite influence on running pattern when running overground or on a treadmill.
abstract: OBJECTIVE
  Minimalist running shoes are designed to induce a foot strike made more with the forepart of the foot. The main changes made on minimalist shoe consist in decreasing the height difference between fore and rear parts of the sole (drop). Barefoot and shod running have been widely compared on overground or treadmill these last years, but the key characteristic effects of minimalist shoes have been yet little studied. The purpose of this study is to find whether the shoe drop has the same effect regardless of the task: overground or treadmill running.
  
  
  METHODS
  Twelve healthy male subjects ran with three shoes of different drops (0, 4, 8 mm) and barefoot on a treadmill and overground. Vertical ground reaction force (vGRF) (transient peak and loading rate) and lower limb kinematics (foot, ankle and knee joint flexion angles) were observed.
  
  
  RESULTS
  Opposite footwear effects on loading rate between the tasks were observed. Barefoot running induced higher loading rates during overground running than the highest drop condition, while it was the opposite during treadmill running. Ankle plantar flexion and knee flexion angles at touchdown were higher during treadmill than overground running for all conditions, except for barefoot which did not show any difference between the tasks.
  
  
  CONCLUSIONS
  Shoe drop appears to be a key parameter influencing running pattern, but its effects on vGRF differ depending on the task (treadmill vs. overground running) and must be considered with caution. Unlike shod conditions, kinematics of barefoot condition was not altered by treadmill running explaining opposite conclusions between the tasks.
authors.affiliation: Aix-Marseille University, CNRS, ISM UMR 7287, 163 avenue de Luminy, 13288, Marseille Cedex 09, France, nicolas.chambon@decathlon.com.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Chambon
authors.forename: Nicolas
authors.initials: N
authors.lastname: Delattre
authors.forename: Nils
authors.initials: N
authors.lastname: Guéguen
authors.forename: Eric
authors.initials: E
authors.lastname: Berton
authors.forename: Guillaume
authors.initials: G
authors.lastname: Rao
mesh_terms: D000843:Ankle Joint / Q000502:physiology*; D001696:Biomechanical Phenomena / Q000502:physiology; D005080:Exercise Test; D005528:Foot / Q000502:physiology*; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D012420:Running / Q000502:physiology*; D012775:Shoes; D055815:Young Adult