France and the United Kingdom agreed to support Poland and in August of 1939, German troops began to gather on the Polish border. By September 1st, Germany launched an invasion of Poland.
The brachial plexus is a network of nerves that originate in the neck region and branch off to form most of the other nerves that control movement and sensation in the upper limbs, including the shoulder, arm, forearm, and hand.
Interscalene Nerve Block. 1  The plexus is formed from the anterior rami of C5-8 and most of T1. Contributions to the plexus also come from C4 and T2, and occasionally the plexus is mainly derived from C4-8 (âpre-fixedâ plexus), or from C6-T2 (âpost-fixedâ plexus).