RT Journal A1 Greenwald J T1 MEchanics JF JAMA JO JAMA YR 2010 FD September 8 VO 304 IS 10 SP 1048 OP 1048 DO 10.1001/jama.2010.1138 UL http://dx.doi.org/10.1001/jama.2010.1138 AB