RT Article T1 Low back pain in the United States: Incidence and risk factors for presentation in the emergency setting JF The spine journal VO 12 IS 1 SP 63 OP 70 A1 Waterman, Brian R. A2 Schoenfeld, Andrew J. A2 Belmont, Philip J. 1969- LA English YR 2012 UL https://krimdok.uni-tuebingen.de/Record/191261393X DO 10.1016/j.spinee.2011.09.002