title: Can ultrasound measurements of muscle thickness be used to measure the size of individual quadriceps muscles in people with patellofemoral pain?
abstract: OBJECTIVE
  Selective atrophy of vastus medialis oblique (VMO) may be present in patellofemoral pain (PFP). This study investigated the validity of real-time ultrasound in measuring the thickness of each quadriceps muscle.
  
  
  METHODS
  Cross sectional-Validity.
  
  
  METHODS
  University laboratory.
  
  
  METHODS
  10 limbs, 5 people with unilateral PFP.
  
  
  METHODS
  The thickness of VMO, vastus lateralis (VL), vastus intermedius (VI), rectus femoris (RF), and vastus medialis (VM) measured with ultrasound were compared to magnetic resonance imaging (MRI) muscle thickness measurements, using Pearson's (r), and compared to MRI muscle cross-sectional area (CSA) measurements, using Spearman's correlation coefficient (rho).
  
  
  RESULTS
  There was a good correlation between ultrasound and MRI measures of the thickness of each superficial quadriceps muscle VMO (r = 0.86), VM (r = 0.86), VL (r = 0.94), RF (r = 0.86), and a poor for VI (r = 0.37). Ultrasound measures had a good correlation to MRI muscle CSA measures for VL (rho = 0.83) and RF (rho = 0.88), moderate for VM (rho = 0.73), and poor for VMO (rho = 0.20), and VI (rho = 0.310).
  
  
  CONCLUSIONS
  Real-time ultrasound muscle thickness measurements are correlated to MRI measured thickness of superficial quadriceps muscles (VMO, VL, VL, and RF) in PFP.
authors.affiliation: School of Allied Health, La Trobe University, Bundoora, Victoria 3086 Australia. Electronic address: lsgiles@students.latrobe.edu.au.
authors.forename: Lachlan S
authors.initials: LS
authors.lastname: Giles
authors.affiliation: School of Allied Health, La Trobe University, Bundoora, Victoria 3086 Australia.
authors.forename: Kate E
authors.initials: KE
authors.lastname: Webster
authors.affiliation: School of Allied Health, La Trobe University, Bundoora, Victoria 3086 Australia.
authors.forename: Jodie A
authors.initials: JA
authors.lastname: McClelland
authors.affiliation: School of Primary Health Care, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria 3800 Australia.
authors.forename: Jill
authors.initials: J
authors.lastname: Cook
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D046788:Patellofemoral Pain Syndrome / Q000000981:diagnostic imaging* / Q000473:pathology; D052097:Quadriceps Muscle / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D014463:Ultrasonography; D055815:Young Adult
keywords: Atrophy; Measurement; VMO; Validity