Position of trunk injury of brachial plexus on MRI Locati on Damage No damage Total Amou nt percenta ge Amou nt percenta ge Amou nt percenta ge Upper 18 30, 0 42 70, 0 60 100 Middle 12 20, 0 48 80, 0 60 100 Lower 13 21, 7 47 78, 3 60 100 Total 43 23, 9 137 76, 1 180 100 17 Table 3.25.