I don't have any direct links to studies as I'm not a member of any clinical science sites. I went over this in my Complementary/ Alternative Therapies (CAM) class and it was greatly disproven by scientific studies.
I,m also into different natural healing methods myself. I have used circular , low gauss magnets that have alternating magnetic fields for soft tissue injuries of the thigh, calf, trap muscles,lower back muscles,wrist carpal tunnel syndrome, and for tennis elbow with great success.