Effect of magnetic knee wrap on quadriceps strength in patients with symptomatic knee osteoarthritis.
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.
Chen
Chung-Yao
CY
Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital, Keelung, Taiwan. jongyau2002@gmail.com
Chen
Chia-Ling
CL
Hsu
Steele Chih-Chin
SC
Chou
Shih-Wei
SW
Wang
Kun-Chung
KC
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