title: Diagnostic accuracy of the electromyography parameters associated with anterior knee pain in the diagnosis of patellofemoral pain syndrome.
abstract: OBJECTIVE
  To assess the diagnostic accuracy of the surface electromyography (sEMG) parameters associated with referred anterior knee pain in diagnosing patellofemoral pain syndrome (PFPS).
  
  
  METHODS
  Sensitivity and specificity analysis.
  
  
  METHODS
  Physical rehabilitation center and laboratory of biomechanics and motor control.
  
  
  METHODS
  Pain-free subjects (n=29) and participants with PFPS (n=22) selected by convenience.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  The diagnostic accuracy was calculated for sEMG parameters' reliability, precision, and ability to differentiate participants with and without PFPS. The selected sEMG parameter associated with anterior knee pain was considered as an index test and was compared with the reference standard for the diagnosis of PFPS. Intraclass correlation coefficient, SEM, independent t tests, sensitivity, specificity, negative and positive likelihood ratios, and negative and positive predictive values were used for the statistical analysis.
  
  
  RESULTS
  The medium-frequency band (B2) parameter was reliable (intraclass correlation coefficient=.80-.90), precise (SEM=2.71-3.87 normalized unit), and able to differentiate participants with and without PFPS (P<.05). The association of B2 with anterior knee pain showed positive diagnostic accuracy values (specificity, .87; sensitivity, .70; negative likelihood ratio, .33; positive likelihood ratio, 5.63; negative predictive value, .72; and positive predictive value, .86).
  
  
  CONCLUSIONS
  The results provide evidence to support the use of EMG signals (B2-frequency band of 45-96 Hz) of the vastus lateralis and vastus medialis muscles with referred anterior knee pain in the diagnosis of PFPS.
authors.affiliation: Physical Therapy Department, School of Science and Technology, University of São Paulo State, Presidente Prudente, SP, Brazil; Bioengineering Postgraduate Program, São Carlos School of Engineering, University of São Paulo, São Carlos, SP, Brazil.
authors.forename: Deisi
authors.initials: D
authors.lastname: Ferrari
authors.affiliation: Physical Therapy Department, School of Science and Technology, University of São Paulo State, Presidente Prudente, SP, Brazil; Bioengineering Postgraduate Program, São Carlos School of Engineering, University of São Paulo, São Carlos, SP, Brazil.
authors.forename: Heloyse Uliam
authors.initials: HU
authors.lastname: Kuriki
authors.affiliation: Neuroscience Program and Biomedical Engineering Laboratory, University of São Paulo, SP, Brazil.
authors.forename: Cristiano Rocha
authors.initials: CR
authors.lastname: Silva
authors.affiliation: Physical Therapy Department, School of Science and Technology, University of São Paulo State, Presidente Prudente, SP, Brazil; Bioengineering Postgraduate Program, São Carlos School of Engineering, University of São Paulo, São Carlos, SP, Brazil.
authors.forename: Neri
authors.initials: N
authors.lastname: Alves
authors.affiliation: Physical Therapy Department, School of Science and Technology, University of São Paulo State, Presidente Prudente, SP, Brazil. Electronic address: micolis@fct.unesp.br.
authors.forename: Fábio
authors.initials: F
authors.lastname: Mícolis de Azevedo
mesh_terms: D000293:Adolescent; D004576:Electromyography; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D059352:Musculoskeletal Pain / Q000209:etiology / Q000503:physiopathology*; D010147:Pain Measurement; D057071:Patellofemoral Joint; D046788:Patellofemoral Pain Syndrome / Q000150:complications / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D052097:Quadriceps Muscle / Q000503:physiopathology*; D012815:Signal Processing, Computer-Assisted; D055815:Young Adult
keywords: Anterior knee pain syndrome; Electromyography; Rehabilitation; Sensitivity; Specificity