Brachial plexus I/O & injury

C5,6,7->UPPER trunk->MUSCULOcutaneous (think upper trunk helps you show-UP your MUSCLes [supinate forearm and elbow flex--how else do you show your big guns?])

C7->middle trunk->Radial, Axillary, and Median (remember Radial injury=wRist dRop [posterior cord])

C8,T1->lower trunk->Ulnar (UL=LOW backwards and my U's look like C's for Claw hand)

Radial N injury doesn't sound Profundly Humerous (profunda brachial A near Radial N)