title: Validation of the movement system impairment-based classification in patients with knee pain.
abstract: BACKGROUND
  Categorizing patients with knee pain problems based on pathoanatomical sources has not proved to be the most effective method for directing physical therapy interventions. Movement system impairment (MSI) classification system may be an alternative in the assessment, diagnosis, and management of patients with knee pain. No previous study has been conducted to validate the proposed system in these patients.
  
  
  OBJECTIVE
  To assess construct validity of the MSI classification system in patients with knee pain.
  
  
  METHODS
  A cross-sectional methodological study.
  
  
  METHODS
  Rasul Akram Hospital.
  
  
  METHODS
  One hundred eighty subjects with knee pain aged 18-65 years.
  
  
  METHODS
  The MSI classification recognizes seven categories of knee pain problems based on the findings from the symptoms and signs assessment. Three physical therapists examined subjects with knee pain. A principal component analysis (PCA) was used to derive proposed categories. Eigenvalues and a scree plot were also used to determine the factor retention.
  
  
  RESULTS
  Four factors related to three proposed categories were extracted from the PCA. Two factors were related to tibiofemoral rotation (TFR) category. The other two factors were related to proposed categories patellar lateral glide (PLG) and tibiofemoral hypomobility (TFHypo).
  
  
  CONCLUSIONS
  The results provided evidence for the construct validity of three (TFR, PLG, and TFHypo) of the seven categories proposed by MSI classification. In addition TFR was subcategorized into two groups which were named as tibial lateral rotation (TLR) and femoral adduction/medial rotation (FAdd/MR) in the present study.
authors.affiliation: Department of Physical Therapy, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Mehrnaz
authors.initials: M
authors.lastname: Kajbafvala
authors.affiliation: Department of Physical Therapy, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Ismail
authors.initials: I
authors.lastname: Ebrahimi-Takamjani
authors.affiliation: Department of Physical Therapy, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Electronic address: mahyarsalavati@gmail.com.
authors.forename: Mahyar
authors.initials: M
authors.lastname: Salavati
authors.affiliation: Department of Statistical Research and Information Technology, Institute for Research and Planning in Higher Education, Tehran, Iran.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Saeedi
authors.affiliation: Department of Physical Therapy, Rehabilitation Faculty, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Zinat
authors.initials: Z
authors.lastname: Ashnagar
authors.affiliation: Department of Physical Therapy, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Pourahmadi
authors.affiliation: Musculoskeletal Rehabilitation Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Mohammad Jafar
authors.initials: MJ
authors.lastname: Shaterzadeh-Yazdi
authors.affiliation: Department of Physical Therapy, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Amiri
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D010146:Pain / Q000145:classification*; D010147:Pain Measurement / Q000379:methods*; D055815:Young Adult
keywords: Classification; Impairment; Knee; Principal component analysis; Validity