title: Dynamic Patterns of Forces and Loading Rate in Runners with Unilateral Plantar Fasciitis: A Cross-Sectional Study.
abstract: OBJECTIVE
  The etiology of plantar fasciitis (PF) has been related to several risk factors, but the magnitude of the plantar load is the most commonly described factor. Although PF is the third most-common injury in runners, only two studies have investigated this factor in runners, and their results are still inconclusive regarding the injury stage.
  
  
  OBJECTIVE
  Analyze and compare the plantar loads and vertical loading rate during running of runners in the acute stage of PF to those in the chronic stage of the injury in relation to healthy runners.
  
  
  METHODS
  Forty-five runners with unilateral PF (30 acute and 15 chronic) and 30 healthy control runners were evaluated while running at 12 km/h for 40 meters wearing standardized running shoes and Pedar-X insoles. The contact area and time, maximum force, and force-time integral over the rearfoot, midfoot, and forefoot were recorded and the loading rate (20-80% of the first vertical peak) was calculated. Groups were compared by ANOVAs (p<0.05).
  
  
  RESULTS
  Maximum force and force-time integral over the rearfoot and the loading rate was higher in runners with PF (acute and chronic) compared with controls (p<0.01). Runners with PF in the acute stage showed lower loading rate and maximum force over the rearfoot compared to runners in the chronic stage (p<0.01).
  
  
  CONCLUSIONS
  Runners with PF showed different dynamic patterns of plantar loads during running over the rearfoot area depending on the injury stage (acute or chronic). In the acute stage of PF, runners presented lower loading rate and forces over the rearfoot, possibly due to dynamic mechanisms related to pain protection of the calcaneal area.
authors.affiliation: University of Sao Paulo, Physical Therapy, Speech and Occupational Therapy Department, School of Medicine, São Paulo, Brazil; University of Santo Amaro, Physical Therapy Department, School of Medicine, São Paulo, Brazil.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Ribeiro
authors.affiliation: University of Sao Paulo, Physical Therapy, Speech and Occupational Therapy Department, School of Medicine, São Paulo, Brazil.
authors.forename: Silvia Maria Amado
authors.initials: SM
authors.lastname: João
authors.affiliation: University of Sao Paulo, Physical Therapy, Speech and Occupational Therapy Department, School of Medicine, São Paulo, Brazil.
authors.forename: Roberto Casanova
authors.initials: RC
authors.lastname: Dinato
authors.affiliation: University of Sao Paulo, Physical Therapy, Speech and Occupational Therapy Department, School of Medicine, São Paulo, Brazil.
authors.forename: Vitor Daniel
authors.initials: VD
authors.lastname: Tessutti
authors.affiliation: University of Sao Paulo, Physical Therapy, Speech and Occupational Therapy Department, School of Medicine, São Paulo, Brazil.
authors.forename: Isabel Camargo Neves
authors.initials: IC
authors.lastname: Sacco
mesh_terms: D000208:Acute Disease; D000328:Adult; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D036981:Fasciitis, Plantar / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012420:Running / Q000293:injuries / Q000502:physiology*; D016474:Weight-Bearing