title: Lower Extremity Biomechanics and Self-Reported Foot-Strike Patterns Among Runners in Traditional and Minimalist Shoes.
abstract: BACKGROUND
  The injury incidence rate among runners is approximately 50%. Some individuals have advocated using an anterior-foot-strike pattern to reduce ground reaction forces and injury rates that they attribute to a rear-foot-strike pattern. The proportion of minimalist shoe wearers who adopt an anterior-foot-strike pattern remains unclear.
  
  
  OBJECTIVE
  To evaluate the accuracy of self-reported foot-strike patterns, compare negative ankle- and knee-joint angular work among runners using different foot-strike patterns and wearing traditional or minimalist shoes, and describe average vertical-loading rates.
  
  
  METHODS
  Descriptive laboratory study.
  
  
  METHODS
  Research laboratory.
  
  
  METHODS
  A total of 60 healthy volunteers (37 men, 23 women; age = 34.9 ± 8.9 years, height = 1.74 ± 0.08 m, mass = 70.9 ± 13.4 kg) with more than 6 months of experience wearing traditional or minimalist shoes were instructed to classify their foot-strike patterns.
  
  
  METHODS
  Participants ran in their preferred shoes on an instrumented treadmill with 3-dimensional motion capture.
  
  
  METHODS
  Self-reported foot-strike patterns were compared with 2-dimensional video assessments. Runners were classified into 3 groups based on video assessment: traditional-shoe rear-foot strikers (TSR; n = 22), minimalist-shoe anterior-foot strikers (MSA; n = 21), and minimalist-shoe rear-foot strikers (MSR; n = 17). Ankle and knee negative angular work and average vertical-loading rates during stance phase were compared among groups.
  
  
  RESULTS
  Only 41 (68.3%) runners reported foot-strike patterns that agreed with the video assessment (κ = 0.42, P < .001). The TSR runners demonstrated greater ankle-dorsiflexion and knee-extension negative work than MSA and MSR runners (P < .05). The MSA (P < .001) and MSR (P = .01) runners demonstrated greater ankle plantar-flexion negative work than TSR runners. The MSR runners demonstrated a greater average vertical-loading rate than MSA and TSR runners (P < .001).
  
  
  CONCLUSIONS
  Runners often cannot report their foot-strike patterns accurately and may not automatically adopt an anterior-foot-strike pattern after transitioning to minimalist running shoes.
authors.affiliation: US Military-Baylor University Sports Medicine Doctoral Program, Keller Army Community Hospital, West Point, NY;
authors.forename: Donald L
authors.initials: DL
authors.lastname: Goss
authors.affiliation: University of North Carolina at Chapel Hill;
authors.forename: Michael
authors.initials: M
authors.lastname: Lewek
authors.affiliation: University of North Carolina at Chapel Hill;
authors.forename: Bing
authors.initials: B
authors.lastname: Yu
authors.affiliation: University of North Carolina at Chapel Hill;
authors.forename: William B
authors.initials: WB
authors.lastname: Ware
authors.affiliation: System for Health and Performance Triad, Defense Health Headquarters, Falls Church, VA.
authors.forename: Deydre S
authors.initials: DS
authors.lastname: Teyhen
authors.affiliation: University of North Carolina at Chapel Hill;
authors.forename: Michael T
authors.initials: MT
authors.lastname: Gross
mesh_terms: D000328:Adult; D000843:Ankle Joint / Q000502:physiology; D001696:Biomechanical Phenomena / Q000502:physiology; D005080:Exercise Test; D005260:Female; D005528:Foot / Q000502:physiology*; D064368:Healthy Volunteers; D006801:Humans; D007719:Knee Joint / Q000502:physiology; D035002:Lower Extremity / Q000502:physiology; D008297:Male; D009068:Movement / Q000502:physiology; D012420:Running / Q000502:physiology*; D057566:Self Report; D012775:Shoes; D013639:Tarsal Bones / Q000502:physiology
keywords: barefoot running; ground reaction forces; loading rate; negative work