RT Journal Article SR Electronic T1 Extrathoracic muscle wasting in exacerbations of COPD: no longer outside the region of interest JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 530 OP 531 DO 10.1136/thoraxjnl-2020-216647 VO 76 IS 6 A1 Greening, Neil J A1 Polkey, Michael I A1 McAuley, Hamish Joseph Cameron YR 2021 UL http://thorax.bmj.com/content/76/6/530.abstract AB