title: Associations of foot posture and function to lower extremity pain: results from a population-based foot study.
abstract: OBJECTIVE
  Studies have implicated foot posture and foot function as risk factors for lower extremity pain. Empirical population-based evidence for this assertion is lacking; therefore, the purpose of this study was to evaluate cross-sectional associations of foot posture and foot function to lower extremity joint pain in a population-based study of adults.
  
  
  METHODS
  Participants were members of the Framingham Foot Study. Lower extremity joint pain was determined by the response to the National Health and Nutrition Examination Survey-type question, "On most days do you have pain, aching or stiffness in your (hips, knees, ankles, or feet)?" The Modified Arch Index classified participants as having planus, rectus (referent), or cavus foot posture. The Center of Pressure Excursion Index classified participants as having overpronated, normal (referent), or oversupinated foot function. Crude and adjusted (age, sex, and body mass index) logistic regression determined associations of foot posture and function to lower extremity pain.
  
  
  RESULTS
  Participants with planus structure had higher odds of knee (odds ratio [OR] 1.57, 95% confidence interval [95% CI] 1.24-1.99) or ankle (OR 1.47, 95% CI 1.05-2.06) pain, whereas those with a cavus foot structure had increased odds of ankle pain only (OR 7.56, 95% CI 1.99-28.8) and pain at 1 lower extremity site (OR 1.37, 95% CI 1.04-1.80). Associations between foot function and lower extremity joint pain were not statistically significant except for a reduced risk of hip pain in those with an oversupinated foot function (OR 0.69, 95% CI 0.51-0.93).
  
  
  CONCLUSIONS
  These findings offer a link between foot posture and lower extremity pain, highlighting the need for longitudinal or intervention studies.
authors.affiliation: Glasgow Caledonian University, Glasgow, Scotland, UK.
authors.forename: Jody L
authors.initials: JL
authors.lastname: Riskowski
authors.forename: Alyssa B
authors.initials: AB
authors.lastname: Dufour
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Hagedorn
authors.forename: Howard J
authors.initials: HJ
authors.lastname: Hillstrom
authors.forename: Virginia A
authors.initials: VA
authors.lastname: Casey
authors.forename: Marian T
authors.initials: MT
authors.lastname: Hannan
mesh_terms: D000843:Ankle Joint / Q000503:physiopathology*; D018771:Arthralgia / Q000175:diagnosis / Q000503:physiopathology*; D015992:Body Mass Index; D005260:Female; D005500:Follow-Up Studies; D005528:Foot / Q000503:physiopathology*; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011159:Population Surveillance / Q000379:methods*; D011187:Posture / Q000502:physiology*; D011312:Pressure; D016059:Range of Motion, Articular / Q000502:physiology*; D012189:Retrospective Studies; D012307:Risk Factors