The branches to the deltoid muscle were located at the lateral part in the initial segment of the axillary nerve, the lateral fascicular groups around the inferior border of the subscapularis muscle and the anterior branch around inferior border of the teres minor muscle respectively. 三角肌肌支在腋神经起始段、四边孔前界和后界处分别位于腋神经主干的外侧半、外侧束组和前侧分支;