title: Effects of joint effusion on quadriceps muscles in patients with knee osteoarthritis.
abstract: OBJECTIVE
  To evaluate the effect of knee effusion on the quadriceps muscle in patients with knee osteoarthritis (OA).
  
  
  METHODS
  Single-blind, randomized, controlled clinical trial.
  
  
  METHODS
  Single medical center.
  
  
  METHODS
  Forty subjects with knee OA were assigned to a experimental (n = 20) or control (n = 20) group.
  
  
  METHODS
  Quadriceps torque and root mean square (RMS) values of surface electromyography (EMG) of the vastus medialis and vastus lateralis muscles were measured during a maximal isometric contraction at 60° knee flexion. Thereafter, 20 mL of normal saline was injected into the knee joint of the experimental group. Quadriceps torque and RMS values were again measured.
  
  
  RESULTS
  Five subjects did not complete the study. No significant difference in quadriceps peak torque or RMS of EMG activity was observed at baseline, pre-effusion, or post-effusion measures in either group. The experimental group showed no significant change in quadriceps peak torque or RMS of EMG activity in any period compared with the control group.
  
  
  CONCLUSIONS
  These results demonstrate that a 20 ml joint effusion did not affect peak torque or RMS values of the quadriceps muscle in patients with knee OA.
authors.affiliation: Department of Rehabilitation Medicine, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Seong Hoon
authors.initials: SH
authors.lastname: Lim
authors.affiliation: Department of Rehabilitation Medicine, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Bo Young
authors.initials: BY
authors.lastname: Hong
authors.affiliation: Department of Rehabilitation Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Jee Hae
authors.initials: JH
authors.lastname: Oh
authors.affiliation: Department of Rehabilitation Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. Electronic address: ljikyh@catholic.ac.kr.
authors.forename: Jong In
authors.initials: JI
authors.lastname: Lee
mesh_terms: D004576:Electromyography / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007270:Injections, Intra-Articular; D007537:Isometric Contraction / Q000502:physiology*; D007719:Knee Joint; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000188:drug therapy* / Q000503:physiopathology; D052097:Quadriceps Muscle / Q000503:physiopathology*; D016037:Single-Blind Method; D012965:Sodium Chloride / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D012965:Sodium Chloride
keywords: Effusion; Knee; Osteoarthritis; Quadriceps