title: Pressure algometry is a useful tool to quantify pain in the medial part of the knee: an intra- and inter-reliability study in healthy subjects.
abstract: OBJECTIVE
  Pain quantification is essential for diagnostic and pain monitoring purposes in disorders around the knee. Pressure algometry is a method described to determine pressure pain threshold (PPT) by applying controlled pressure to a given body point. The purpose of this study was to determine the reliability of this method when it was applied to the medial part of the proximal tibia metaphysis and to evaluate the PPT levels between genders.
  
  
  METHODS
  Fifty healthy (mean age; 46.9) volunteers were recruited, 25 men and 25 women. Pressure algometry was applied to a 1 cm(2)-probe area on the medial part of the knee by 2 raters. Intra- and interclass correlation (ICC) was obtained and differences between genders were evaluated. Bland-Altman plots were performed to evaluate the variability of the measures.
  
  
  RESULTS
  The mean values of PPT obtained by rater 1 and 2 were 497.5 Kpa and 489 Kpa respectively. The intrarater reliability values (95% IC) for rater 1 and 2 were 0.97 (0.95-0.98) and 0.84 (0.73-0.90) respectively. With regard to interrater reliability, the ICC (95% IC) for the first measurement was 0.92 (0.87-0.95) and 0.86 (0.78-0.92) for the second one. Women showed significant lower values of PPT than men. The Bland-Altmand plots showed excellent agreement.
  
  
  CONCLUSIONS
  Pressure algometry has excellent reliability when it is applied to the medial part of the proximal metaphysis of the tibia. Women have lower values of PTT than men. The high reliability of the PA in an individual volunteer makes it a more valuable tool for longitudinal assessment of a given patient than for comparison between them.
  
  
  METHODS
  Level III. Prospective study.
authors.affiliation: Orthopaedic department, Consorci Sanitari de ĺAnoia, Avinguda Catalunya 11, 08700 Igualada, Barcelona, Spain.
authors.forename: X
authors.initials: X
authors.lastname: Pelfort
authors.affiliation: Orthopaedic department, Hospital del Mar, Universitat Autònoma de Barcelona, Passeig Marítim 25-29, 08003 Barcelona, Spain; IMIM, Hospital del Mar Medical Research Institute, Barcelona, Spain. Electronic address: rtorresclaramunt@parcdesalutmar.cat.
authors.forename: R
authors.initials: R
authors.lastname: Torres-Claramunt
authors.affiliation: Orthopaedic department, Hospital del Mar, Universitat Autònoma de Barcelona, Passeig Marítim 25-29, 08003 Barcelona, Spain.
authors.forename: J F
authors.initials: JF
authors.lastname: Sánchez-Soler
authors.affiliation: Orthopaedic department, Hospital del Mar, Universitat Autònoma de Barcelona, Passeig Marítim 25-29, 08003 Barcelona, Spain; IMIM, Hospital del Mar Medical Research Institute, Barcelona, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Hinarejos
authors.affiliation: Orthopaedic department, Hospital del Mar, Universitat Autònoma de Barcelona, Passeig Marítim 25-29, 08003 Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Leal-Blanquet
authors.affiliation: Orthopaedic department, Hospital General de Granollers, Universitat Internacional de Catalunya, Granollers, Barcelona, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Valverde
authors.affiliation: Orthopaedic department, Hospital del Mar, Universitat Autònoma de Barcelona, Passeig Marítim 25-29, 08003 Barcelona, Spain; IMIM, Hospital del Mar Medical Research Institute, Barcelona, Spain.
authors.forename: J C
authors.initials: JC
authors.lastname: Monllau
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007719:Knee Joint; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods*; D017288:Pain Threshold; D010173:Palpation / Q000295:instrumentation; D011446:Prospective Studies; D015203:Reproducibility of Results; D012737:Sex Factors
keywords: Algometry; Knee; Pain; Pressure; Threshold