Pulsed electromagnetic fields for postmenopausal osteoporosis and concomitant lumbar osteoarthritis in southwest China using proximal femur bone mineral density as the primary endpoint: study protocol for a randomized controlled trial June 9, 2015 Trials 2015, 16:265Â doi:10.1186/s13063-015-0780-4 Hui-Fang Liu and Hong-Chen He contributed equally to this work. Published: 10 June 2015