title: Risk factors for foot and ankle disorders among assembly plant workers.
abstract: BACKGROUND
  Jobs that necessitate prolonged standing and walking activities are commonly associated with worker's complaints of foot and ankle pain. The objective of this study was to determine the relative contributions of work activity (time spent standing, walking, or sitting), floor surface characteristics, weight, BMI, age, foot biomechanics, and other demographic and medical history factors to the prevalence of foot and ankle disorders.
  
  
  METHODS
  A cross-sectional observational study design was used to evaluate employees of an engine manufacturing plant. The main outcome variable was foot or ankle disorders defined by pain and a positive physical examination. The independent variables included baseline demographics, medical history, ergonomic exposures, psychosocial factors, shoe characteristics and foot biomechanics.
  
  
  RESULTS
  Twenty-four percent of the cohort met the case definition of foot/ankle disorder with 10% defined as new cases. Fifty-two percent had symptoms of foot/ankle. An increased risk of presenting with foot/ankle disorders was associated with high metatarsal pressure on gait assessment, increased time spent walking, female gender, reported high job dissatisfaction, a history of rheumatoid arthritis, osteoporosis or vascular disorder. For the truck/forklift drivers, an increased number of times getting in and out of the vehicle was associated with a higher prevalence of ankle/foot problems.
  
  
  CONCLUSIONS
  An increased risk is associated with higher metatarsal pressure and increased time spent walking. These findings suggest several options for primary and secondary prevention strategies. The use of shoe orthoses with a medial longitudinal arch and metatarsal pad as well as including optional sit/stand workstations may be helpful.
authors.affiliation: Department of Physical Medicine and Rehabilitation, University of Michigan Health System, Ann Arbor, Michigan, USA. rawerner@umich.edu
authors.forename: Robert A
authors.initials: RA
authors.lastname: Werner
authors.forename: Nancy
authors.initials: N
authors.lastname: Gell
authors.forename: Anne
authors.initials: A
authors.lastname: Hartigan
authors.forename: Neal
authors.initials: N
authors.lastname: Wiggermann
authors.forename: W Monroe
authors.initials: WM
authors.lastname: Keyserling
mesh_terms: D000328:Adult; D000368:Aged; D016512:Ankle Injuries / Q000453:epidemiology* / Q000209:etiology; D018771:Arthralgia / Q000453:epidemiology* / Q000209:etiology; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D006804:Ergonomics; D005260:Female; D018409:Foot Injuries / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009784:Occupational Diseases / Q000453:epidemiology* / Q000209:etiology; D016273:Occupational Exposure / Q000009:adverse effects*; D016017:Odds Ratio; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D055815:Young Adult