This study examined the effects of magnetic fields on synovitis in rats. Results showed that the placement of a 3800-gauss magnet on the bottom of the cage significantly suppressed inflammation associated with the condition, relative to controls.

A. Weinberger, Treatment of Experimental Inflammatory Synovitis with Continuous Magnetic Field, Isr Journal of Med Sci, 32(12), December 1996, p. 1197-1201.