title: Shoe heel abrasion and its possible biomechanical cause: a transversal study with infantry recruits.
abstract: BACKGROUND
  Excessive shoe heel abrasion is of concern to patients and shoe manufacturers, but little scientific information is available about this feature and its possible causes. The purpose of this study was to relate this phenomenon with biomechanical factors that could predispose to shoe heel abrasion.
  
  
  METHODS
  Ninety-seven recruits (median age 25) were enrolled in this study. Shoe abrasion was assessed manually with a metric plastic tape on the posterior part of the heel that comes in contact with the ground. The number of sprains, foot alignment, and calf muscle shortening (Silfverskiold test) was also assessed in order to relate it with shoe heel abrasion. After using our exclusion criteria, 86 recruits and 172 were considered for this study.
  
  
  RESULTS
  The most common abrasion site was the lateral portion of the heel surface (50 %). Forty-four percent of the participants had neutral hind-foot alignment and 39 % had valgus alignment. Twenty-six (30 %) patients have had previous ankle or foot sprains. Neutral foot was related with less calf muscle shortening. On the other hand, valgus hind-foot alignment was more associated with Achilles shortening (p < 0.05). Patients with neutral alignment were associated with more uniform shoe heel abrasion and varus feet were associated with more central and lateral abrasion (p < 0.05). The pattern of shoe heel abrasion was not statistically related with calf muscle shortening nor with number of sprains.
  
  
  CONCLUSIONS
  This study was able to correlate shoe heel abrasion with biomechanical causes (neutral alignment-uniform abrasion/varus alignment-central and lateral abrasion). More effort has to be done to continue evaluating outsole abrasion with its possible biomechanical cause in order to predict and treat possible associated injuries.
authors.affiliation: UFMG-Federal University of Minas Gerais, Juvenal dos santos St, 325, 30380 5030, Belo Horizonte, MG, Brazil. danielbaumfeld@gmail.com.
authors.forename: Daniel
authors.initials: D
authors.lastname: Baumfeld
authors.affiliation: Foot and Ankle Clinic, UNIFESP, Escola Paulista de Medicina, São Paulo, SP, Brazil.
authors.forename: Fernando C
authors.initials: FC
authors.lastname: Raduan
authors.affiliation: Felicio Rocho Hospital, Belo Horizonte, MG, Brazil.
authors.forename: Benjamim
authors.initials: B
authors.lastname: Macedo
authors.affiliation: Madre Teresa Hospital, Belo Horizonte, MG, Brazil.
authors.forename: Thiago Alexandre Alves
authors.initials: TA
authors.lastname: Silva
authors.affiliation: UFMG-Federal University of Minas Gerais, Juvenal dos santos St, 325, 30380 5030, Belo Horizonte, MG, Brazil.
authors.forename: Tiago
authors.initials: T
authors.lastname: Baumfeld
authors.affiliation: Felicio Rocho Hospital, Belo Horizonte, MG, Brazil.
authors.forename: Danilo Fabrino
authors.initials: DF
authors.lastname: Favato
authors.affiliation: UFMG-Federal University of Minas Gerais, Juvenal dos santos St, 325, 30380 5030, Belo Horizonte, MG, Brazil.
authors.forename: Marco Antonio Percope
authors.initials: MA
authors.lastname: de Andrade
authors.affiliation: Foot and Ankle Clinic, UNIFESP, Escola Paulista de Medicina, São Paulo, SP, Brazil.
authors.forename: Caio
authors.initials: C
authors.lastname: Nery
mesh_terms: D000125:Achilles Tendon / Q000473:pathology / Q000502:physiology; D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology*; D006365:Heel / Q000473:pathology* / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008889:Military Personnel; D018579:Patient Selection; D012775:Shoes / Q000009:adverse effects*; D016138:Walking / Q000502:physiology*; D055815:Young Adult