title: Temporal activity of vastus medialis obliquus and vastus lateralis in symptomatic knee osteoarthritis.
abstract: OBJECTIVE
  Knee osteoarthritis has a major impact on quadriceps function, yet its effect on the specific temporal recruitment of vastus medialis obliquus and vastus lateralis is unknown. The aim of this study was to determine the electromyographic onset of vastus medialis obliquus activity relative to that of vastus lateralis in individuals with symptomatic knee osteoarthritis and in an asymptomatic control group during the functional task of stair climbing.
  
  
  METHODS
  Cross-sectional, comprising 41 participants with symptomatic knee osteoarthritis and 33 controls matched for age, sex, and body mass.
  
  
  RESULTS
  No significant differences were detected in the timing of onset of vastus medialis obliquus relative to that of vastus lateralis between the osteoarthritis and control groups. Radiographic osteoarthritis severity, presence of patellofemoral joint disease, and pain intensity did not seem to influence the temporal relationship of the vastii in the osteoarthritis group.
  
  
  CONCLUSIONS
  The presence of symptomatic, radiographic knee osteoarthritis is not associated with deficits in the temporal recruitment of vastus medialis obliquus and vastus lateralis during stair climbing. This implies that selective retraining of the individual components of the quadriceps is not indicated in rehabilitation programs for patients with this disease.
authors.affiliation: Centre for Sports Medicine Research and Education, School of Physiotherapy, The University of Melbourne, Melbourne, Australia.
authors.forename: Rana S
authors.initials: RS
authors.lastname: Hinman
authors.forename: Kim L
authors.initials: KL
authors.lastname: Bennell
authors.forename: Ben R
authors.initials: BR
authors.lastname: Metcalf
authors.forename: Kay M
authors.initials: KM
authors.lastname: Crossley
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004576:Electromyography; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000503:physiopathology*; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000503:physiopathology*; D010147:Pain Measurement; D011859:Radiography; D011930:Reaction Time; D012720:Severity of Illness Index