title: Shear wave elastography properties of vastus lateralis and vastus medialis obliquus muscles in normal subjects and female patients with patellofemoral pain syndrome.
abstract: OBJECTIVE
  The aim of our study was to define and compare the mechanical properties of the vastus lateralis (VL) and vastus medialis obliquus muscles (VMO) by the way of quantitative shear-wave elastography in male and female healthy control (HC) subjects, and in female patients with patellofemoral pain syndrome (PFPS).
  
  
  METHODS
  Twenty-two healthy volunteers (11 male and 11 female) and 11 female patients with anterior knee pain were included in the study. The SWE examinations for VL and VMO were performed while the subjects were performing open kinetic chain exercises in neutral and 30° hip abduction. The contraction capacity (CC) and contraction ratio (CR) values were determined in resting and contraction phases in both hip positions.
  
  
  RESULTS
  The mean elasticity values in the CC for VL and VMO muscles were significantly higher in male HC subjects when compared to female HC subjects (p < 0.05). The CR of the VL muscle in female patients with PFPS was not significantly different than the female HC group. The CR for the VMO muscle was significantly lower in female patients with PFPS when compared to female HC subjects (p < 0.05).
  
  
  CONCLUSIONS
  We found a significant VMO weakness, and this method may provide quantitative data that might influence the diagnosis of muscle weakness, in female patients with PFPS.
authors.affiliation: Cerrahpasa Faculty of Medicine, Department of Orthopaedics and Traumatology, Istanbul University, Kocamustafapasa, Istanbul, 34303, Turkey. huseyinbotanlioglu@yahoo.com
authors.forename: Huseyin
authors.initials: H
authors.lastname: Botanlioglu
authors.forename: Fatih
authors.initials: F
authors.lastname: Kantarci
authors.forename: Gokhan
authors.initials: G
authors.lastname: Kaynak
authors.forename: Yelda
authors.initials: Y
authors.lastname: Unal
authors.forename: Sema
authors.initials: S
authors.lastname: Ertan
authors.forename: Onder
authors.initials: O
authors.lastname: Aydingoz
authors.forename: Rifat
authors.initials: R
authors.lastname: Erginer
authors.forename: Mehmet Can
authors.initials: MC
authors.lastname: Unlu
authors.forename: Ismail
authors.initials: I
authors.lastname: Mihmanli
authors.forename: Muharrem
authors.initials: M
authors.lastname: Babacan
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D054459:Elasticity Imaging Techniques; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D046788:Patellofemoral Pain Syndrome / Q000503:physiopathology*; D052097:Quadriceps Muscle / Q000502:physiology* / Q000503:physiopathology*