title: On the relationship between subjective and objective measures of fatigue.
abstract: OBJECTIVE
  Objective and subjective methods have been used in the past to assess workplace fatigue, but little is known about correlations between them. We examine correlations between subjective and objective measures, including measures collected in a workplace scenario.
  
  
  METHODS
  15 young and 17 older participants were assessed before and after work with four types of fatigue measure: objective physical (posturography), objective mental (psychomotor vigilance task), subjective physical and mental (self-assessment), objective and subjective realistic (oculomotor behaviour, observer-rated facial expression, typing performance).
  
  
  RESULTS
  Pre- and post-test scores were analysed with an ANOVA, significant differences were submitted to a factor analysis. It yielded three factors: one representing posturography, the second self-rated mental and physical fatigue and the third observer-rated facial expression.
  
  
  CONCLUSIONS
  Results advocate the existence of three independent fatigue components: Objective physical fatigue, introspective and extrospective fatigue. Practitioner Summary: This study analyses correlations between different subjective and objective fatigue markers to better understand the complex nature of workplace fatigue. Measurements were conducted directly at the workplace. Results reveal that fatigue comprises three independent fatigue components: Objective physical fatigue, introspective and extrospective fatigue.
authors.affiliation: a Institute of Physiology and Anatomy , German Sport University Cologne , Cologne , Germany.
authors.forename: Ina
authors.initials: I
authors.lastname: Völker
authors.affiliation: a Institute of Physiology and Anatomy , German Sport University Cologne , Cologne , Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Kirchner
authors.affiliation: a Institute of Physiology and Anatomy , German Sport University Cologne , Cologne , Germany.
authors.forename: Otmar Leo
authors.initials: OL
authors.lastname: Bock
mesh_terms: D000328:Adult; D059026:Diagnostic Self Evaluation; D005221:Fatigue / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000523:psychology; D005260:Female; D006801:Humans; D007361:Intelligence Tests; D008297:Male; D008875:Middle Aged; D010808:Physical Examination / Q000379:methods*; D005082:Physical Exertion / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D011603:Psychophysiology; D013223:Statistics as Topic; D014937:Work / Q000502:physiology / Q000523:psychology
keywords: Fatigue markers; fatigue detection; multidimensional construct; workplace