▁of ▁shoulder ▁external ▁rotation . ▁ ▁C lin ical ▁significance ▁ ▁In j ury ▁There ▁are ▁two ▁types ▁of ▁rot ator ▁cu ff ▁inj uries : ▁ac ute ▁tears ▁and ▁chron ic ▁tears . ▁Ac ute ▁tears ▁occur ▁as ▁a ▁result ▁of ▁a ▁sudden ▁movement . ▁This ▁might ▁include ▁throwing ▁a ▁powerful ▁pitch , ▁holding ▁a ▁fast ▁moving ▁ro pe ▁during ▁water ▁sports , ▁falling ▁over ▁onto ▁an ▁out st retch ed ▁hand ▁at ▁speed , ▁or ▁making ▁a ▁sudden ▁thrust ▁with ▁the ▁p addle ▁in ▁k ay aking . ▁ ▁A ▁chron ic ▁te ar ▁develop s ▁over ▁a ▁period ▁of ▁time . ▁They ▁usually ▁occur ▁at ▁or ▁near ▁the ▁tend on , ▁as ▁a ▁result ▁of ▁the ▁tend on ▁rub bing ▁against ▁the ▁underlying ▁b one . ▁The ▁ter es ▁minor ▁is ▁typically ▁normal ▁following ▁a ▁rot ator ▁cu ff ▁te ar . ▁ ▁Im aging ▁ ▁At ro phy ▁of ▁the ▁ter es ▁minor ▁mus cle ▁is ▁often ▁a ▁consequence ▁of ▁a ▁rot ator ▁cu ff ▁te ar , ▁but ▁common ▁isolated ▁ter es ▁minor ▁at roph ies ▁have ▁also ▁been ▁found . ▁A ▁quadr angular ▁space ▁synd rome ▁causes ▁excess ive ▁and ▁or ▁chron ically ▁compression ▁of ▁the ▁structures ▁which ▁pass ▁through ▁this ▁an atom ical ▁tunnel . ▁The ▁ax ill ary ▁n erve ▁and ▁the ▁posterior ▁hum eral ▁circum flex ▁ar tery ▁pass ▁through ▁the ▁space . ▁People ▁affected ▁note ▁shoulder ▁pain ▁and ▁par est hes ia ▁down ▁the ▁arm ▁first ▁and ▁for em ost ▁in ▁ab du