The suprascapular nerve (C5 and C6): originates from the superior trunk of the brachial plexus, passes laterally through the posterior triangle of the neck (Fig. 7.54) and through the suprascapular foramen to enter the posterior scapular region, innervates the supraspinatus and infraspinatus muscles, and is accompanied in the lateral parts of the neck and in the posterior scapular region by the suprascapular artery.