The supraclavicular brachial plexus block targets the brachial plexus at the level of the zone of transition – where the trunks are transformed to fascicles just proximal to the clavicle
The brachial plexus is displayed with the suprascapular nerve (red arrow) and the axillary nerve (blue arrow). The five spinal nerve roots of the brachial plexus are indicated by C5 to T1. Green asterix = superior trunk; red asterix = middle trunk; blue asterix = inferior trunk.