title: Effect of magnetic knee wrap on quadriceps strength in patients with symptomatic knee osteoarthritis.
abstract: OBJECTIVE
  To determine the effects of magnetic knee wrap on isokinetic quadriceps strength in patients with painful knee osteoarthritis (OA).
  
  
  METHODS
  Randomized, double-blinded, placebo-controlled and before-after trial.
  
  
  METHODS
  Rehabilitation clinic in a tertiary hospital.
  
  
  METHODS
  Eligible patients (N=50) (mean age+/-SD, 66.0+/-8.6 y) with mild to moderate knee OA were recruited from the outpatient department and 37 (74%) completed the trial. Only 3 (6%) withdrew due to study-related adverse effects.
  
  
  METHODS
  Wearing the active (n=24) or sham (n=26) magnetic knee wrap for 12 weeks.
  
  
  METHODS
  The primary outcome measure was isokinetic quadriceps strength. Secondary outcome measures included the Health Assessment Questionnaire Disability Index (HAQ-DI) and the Health Assessment Questionnaire (HAQ) Pain Scale.
  
  
  RESULTS
  Using intention-to-treat analyses, the peak isokinetic quadriceps strength increased significantly in the treated leg at 30 degrees/s (P=.007) and 60 degrees/s (P=.022) after wearing the magnetic knee wrap. Compared with baseline, the median strength increase for the treated leg in the study group significantly exceeded that in the control group at week 4 (.05 Nm/kg vs -.09 Nm/kg at 60 degrees/s, P=.038) and week 12 (30 degrees/s, .09 Nm/kg vs .04 Nm/kg, P=.044; 60 degrees/s, .17 Nm/kg vs .02 Nm/kg, P=.031). The HAQ-DI and HAQ Pain Scales improved significantly in both groups. Compared with baseline, the improvement at week 12 in terms of the HAQ-DI in the study group significantly exceeded that in the control group.
  
  
  CONCLUSIONS
  Magnetic knee wrap may significantly facilitate isokinetic quadriceps strength in patients with mild to moderate knee OA.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital, Keelung, Taiwan. jongyau2002@gmail.com
authors.forename: Chung-Yao
authors.initials: CY
authors.lastname: Chen
authors.forename: Chia-Ling
authors.initials: CL
authors.lastname: Chen
authors.forename: Steele Chih-Chin
authors.initials: SC
authors.lastname: Hsu
authors.forename: Shih-Wei
authors.initials: SW
authors.lastname: Chou
authors.forename: Kun-Chung
authors.initials: KC
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004311:Double-Blind Method; D005260:Female; D006304:Health Status; D006801:Humans; D055909:Magnetic Field Therapy; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D018908:Muscle Weakness / Q000209:etiology / Q000534:rehabilitation*; D020370:Osteoarthritis, Knee / Q000150:complications / Q000534:rehabilitation*; D052097:Quadriceps Muscle