title: Relationship between pressure pain thresholds and pain ratings in patients with whiplash-associated disorders.
abstract: OBJECTIVE
  Increased sensitivity to pressure is commonly associated with painful musculoskeletal conditions, including whiplash-associated disorders (WADs). Pressure pain thresholds (PPTs) close to the site of presumed tissue damage are thought to represent the degree of peripheral nociceptive sensitization. PPTs over healthy tissue, away from the site of injury, are a marker of central nervous system hyperexcitability. There is uncertainty, however, as to what extent does the sensitization of the nociceptive system, whether peripheral or central, contribute to the ongoing, habitual pain experienced by people with WAD.
  
  
  METHODS
  One hundred patients with WAD were assessed within 4 weeks of their accident and followed after 3 months; 24-hour average neck pain score, PPTs at the cervical spine and tibialis anterior, demographic factors, and psychological measures were collected.
  
  
  RESULTS
  Cervical PPT and neck pain score were significantly, but weakly correlated (r = -0.20 to -0.33). There was no significant correlation between tibialis anterior PPT and pain score at any time point (r = -0.01 to -0.21). Regression analyses indicated a strong influence of generalized psychological distress and fear avoidance on the relationship between PPT and pain report.
  
  
  CONCLUSIONS
  The competing explanations for these findings are that either PPTs provide a poor marker of peripheral and central sensitivity or that these processes are only weakly related to the day-to-day pain experienced by patients with WAD. The latter explanation is supported by the confounding effect of psychological factors on pain score.
authors.affiliation: *The George Institute for Global Health †the Discipline of Physiotherapy, University of Sydney, New South Wales, Australia. skamper@george.org.au
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Kamper
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Maher
authors.forename: Julia M
authors.initials: JM
authors.lastname: Hush
authors.forename: Ashley
authors.initials: A
authors.lastname: Pedler
authors.forename: Michele
authors.initials: M
authors.lastname: Sterling
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000503:physiopathology* / Q000523:psychology; D009619:Nociceptors / Q000502:physiology; D010147:Pain Measurement / Q000379:methods; D017288:Pain Threshold / Q000502:physiology*; D011312:Pressure; D012044:Regression Analysis; D013315:Stress, Psychological; D011795:Surveys and Questionnaires; D014911:Whiplash Injuries / Q000150:complications / Q000503:physiopathology*; D055815:Young Adult