RT Journal Article SR Electronic T1 The Effects of Shoulder Abduction and External Rotation on the Axillary Vasculature as Examined by Ultrasound JF Regional Anesthesia & Pain Medicine JO Reg Anesth Pain Med FD BMJ Publishing Group Ltd SP 58 OP 58 DO 10.1136/rapm-00115550-199924031-00058 VO 24 IS Suppl 1 A1 Paul H. Willoughby A1 S Petroff A1 J Lok A1 A Sopchak A1 PS Thomas YR 1999 UL http://rapm.bmj.com/content/24/Suppl_1/58.abstract AB