Effect of pulsed electromagnetic fields on biomechanical properties of femur in ovariectomized rats

Objective To test the effect of pulsed electromagnetic fields(PEMFs) with different length of treatment on the biomechanical properties of femurs in ovariectomized rats.Methods Fifty female SD rats were randomly divided into five groups: ① SHAM control(no PEMFs treatment),② OVX0 control(no PEMFs treatment),③ OVXⅠ(PEMFs treatment at 8 Hz frequency with 3.8 mT intensity,20 min daily for 30 days),④ OVXⅡ(PEMFs treatment at 8 Hz frequency with 3.8 mT intensity,40 min daily for 30 days),and ⑤ OVXⅢ(PEMFs treatment at 8 Hz frequency with 3.8 mT intensity,60 min daily for 30 days).All of the rats were subject to bilateral overiectomy except those in the SHAM control group.The biomechanical properties of the femurs were assessed at the end of the PEMFs treatment.Results The rats in the OVX0 control group had significantly lower values in the biomechanical properties than the rats in the other four groups(P0.05 or P0.01).The rats treated with PEMFs showed no significant differences in the biomechanical properties compared with the sham controls(P0.05).Conclusion PEMFs therapy at 8 Hz and 3.8 mT magnetic intensity for 20 to 60 min everyday prevents decline in biomechanical properties of femurs in ovariectomized rat.