[Effects of the PEMFs of different intensity on BMD and biomechanical properties of rabbits' femur].

The effects of the pulsed electromagnetic fields (PEMFs) of different intensity on bone mineral density (BMD) and biomechanical properties of rabbits' femur had been studied. Twenty-seven female white big ear rabbits were randomly divided into three groups. The magnetic groups were fed in 15 Hz PEMFs, which pulse duration was set to be 5 ms (6 h x d(-1)), the magnetic intensity was 10 x 10(-4) T and the other was 20 x 10(-4) T. Control group were just fed in coils, and the instrument of PEMFs was powered off. After six weeks, by examine BMD and biomechanical properties of the rabbits' femur, the effects of these PEMFs were studied. Compared with control group, the values of BMD, maximum load and structural rigidity of magnetic group were significantly increased (P < 0.05). In addition, there was significant increase in values of BMD and structural rigidity in group 10 x 10(-4) T in comparison with group 20 x 10(-4) T (P < 0.05). PEMFs is effective in improving BMD and biomechanical properties. The experiment indicated that there was evident "window-effect" during the treatment by PEMFs. It is favorable to the treatment and prevention of osteoporosis.