title: [Effect of pulsed electromagnetic fields on biomechanical properties of femur in ovariectomized rats].
abstract: 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) OVXo control (no PEMFs treatment), (3) OVX(I) (PEMFs treatment at 8 Hz frequency with 3.8 mT intensity, 20 min daily for 30 days), (4) OVX(II) (PEMFs treatment at 8 Hz frequency with 3. 8 mT intensity, 40 min daily for 30 days), and (5) OVX(III) (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 (P < 0.05 or P < 0.01). The rats treated with PEMFs showed no significant differences in the biomechanical properties compared with the sham controls (P > 0.05).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Physical Medicine & Rehabilitation, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
authors.forename: Deng
authors.initials: D
authors.lastname: Xiao
authors.forename: Lin
authors.initials: L
authors.lastname: Yang
authors.forename: Zhong-jie
authors.initials: ZJ
authors.lastname: Lei
authors.forename: Yong-hong
authors.initials: YH
authors.lastname: Yang
authors.forename: Gao
authors.initials: G
authors.lastname: Qiang
authors.forename: Cheng-qi
authors.initials: CQ
authors.lastname: He
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D004574:Electromagnetic Fields; D005260:Female; D005269:Femur / Q000503:physiopathology*; D055909:Magnetic Field Therapy / Q000379:methods*; D010024:Osteoporosis / Q000503:physiopathology / Q000517:prevention & control / Q000628:therapy*; D010052:Ovariectomy; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley