Department of Physical Therapy, University of Texas Medical Branch, Galveston, USA.
CONTEXT: Static magnets have become an increasingly popular alternative therapy for individuals with musculoskeletal pain despite limited scientific evidence to support their efficacy or safety.
OBJECTIVE: To determine the effects of static magnets on the pain and functional limitations associated with chronic knee pain due to degenerative joint disease.
DESIGN: Double-blind, randomized, controlled clinical trial.
SETTING: Pretests and posttests were conducted in an academic health science center.
PARTICIPANTS: Forty-three ambulatory subjects with chronic pain in 1 or both knee joints who were recruited from outpatient clinics or who volunteered to participate.
INTERVENTION: Subjects wore pads containing magnets or placebos over their painful knee joints for 2 weeks.
MAIN OUTCOME MEASURES: Self-administered ratings of pain and physical function using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and a timed 15-m (50-ft) walk.
RESULTS: Multivariate analysis of covariance revealed significantly greater improvements in the group wearing magnets (P=.002). Univariate analyses indicated that comparative changes in self-rated pain and physical function (P=.002 and .001, respectively) were greater than changes in gait speed (P=.042).
CONCLUSIONS: The application of static magnets over painful knee joints appears to reduce pain and enhance functional movement. However, further study is needed to determine the physiological mechanisms responsible for this analgesic effect.